Merge branch 'upstream' into regression-tests

This commit is contained in:
Trung Nguyen
2024-07-09 08:24:46 -05:00
658 changed files with 74231 additions and 39993 deletions

6
.github/CODEOWNERS vendored
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@ -38,6 +38,7 @@ src/ML-HDNNP/* @singraber
src/ML-IAP/* @athomps src/ML-IAP/* @athomps
src/ML-PACE/* @yury-lysogorskiy src/ML-PACE/* @yury-lysogorskiy
src/ML-POD/* @exapde src/ML-POD/* @exapde
src/ML-UF3/* @monk-04
src/MOFFF/* @hheenen src/MOFFF/* @hheenen
src/MOLFILE/* @akohlmey src/MOLFILE/* @akohlmey
src/NETCDF/* @pastewka src/NETCDF/* @pastewka
@ -58,7 +59,8 @@ src/VTK/* @rbberger
# individual files in packages # individual files in packages
src/GPU/pair_vashishta_gpu.* @andeplane src/GPU/pair_vashishta_gpu.* @andeplane
src/KOKKOS/pair_vashishta_kokkos.* @andeplane src/KOKKOS/pair_vashishta_kokkos.* @andeplane @stanmoore1
src/KOSSOS/pair_pod_kokkos.* @exapde @stanmoore1
src/MANYBODY/pair_vashishta_table.* @andeplane src/MANYBODY/pair_vashishta_table.* @andeplane
src/MANYBODY/pair_atm.* @sergeylishchuk src/MANYBODY/pair_atm.* @sergeylishchuk
src/MANYBODY/pair_nb3b_screened.* @flodesani src/MANYBODY/pair_nb3b_screened.* @flodesani
@ -72,6 +74,8 @@ src/MC/fix_sgcmc.* @athomps
src/REAXFF/compute_reaxff_atom.* @rbberger src/REAXFF/compute_reaxff_atom.* @rbberger
src/KOKKOS/compute_reaxff_atom_kokkos.* @rbberger src/KOKKOS/compute_reaxff_atom_kokkos.* @rbberger
src/REPLICA/fix_pimd_langevin.* @Yi-FanLi src/REPLICA/fix_pimd_langevin.* @Yi-FanLi
src/DPD-BASIC/pair_dpd_coul_slater_long.* @Eddy-Barraud
src/GPU/pair_dpd_coul_slater_long.* @Eddy-Barraud
# core LAMMPS classes # core LAMMPS classes
src/lammps.* @sjplimp src/lammps.* @sjplimp

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@ -15,7 +15,7 @@ jobs:
build: build:
name: MacOS Unit Test name: MacOS Unit Test
if: ${{ github.repository == 'lammps/lammps' }} if: ${{ github.repository == 'lammps/lammps' }}
runs-on: macos-latest runs-on: macos-13
env: env:
CCACHE_DIR: ${{ github.workspace }}/.ccache CCACHE_DIR: ${{ github.workspace }}/.ccache
@ -43,6 +43,8 @@ jobs:
working-directory: build working-directory: build
run: | run: |
ccache -z ccache -z
python3 -m venv macosenv
source macosenv/bin/activate
python3 -m pip install numpy python3 -m pip install numpy
python3 -m pip install pyyaml python3 -m pip install pyyaml
cmake -C ../cmake/presets/clang.cmake \ cmake -C ../cmake/presets/clang.cmake \

11
.gitignore vendored
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@ -43,12 +43,12 @@ Thumbs.db
#cmake #cmake
/build* /build*
/CMakeCache.txt CMakeCache.txt
/CMakeFiles/ CMakeFiles
/Testing
/Makefile /Makefile
/Testing Testing
/cmake_install.cmake Temporary
cmake_install.cmake
/lmp /lmp
out/Debug out/Debug
out/RelWithDebInfo out/RelWithDebInfo
@ -60,3 +60,4 @@ src/Makefile.package.settings-e
/cmake/build/x64-Debug-Clang /cmake/build/x64-Debug-Clang
/install/x64-GUI-MSVC /install/x64-GUI-MSVC
/install /install
.Rhistory

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@ -23,6 +23,7 @@ project(lammps CXX)
set(SOVERSION 0) set(SOVERSION 0)
get_property(BUILD_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG) get_property(BUILD_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
include(GNUInstallDirs)
get_filename_component(LAMMPS_DIR ${CMAKE_CURRENT_SOURCE_DIR}/.. ABSOLUTE) get_filename_component(LAMMPS_DIR ${CMAKE_CURRENT_SOURCE_DIR}/.. ABSOLUTE)
get_filename_component(LAMMPS_LIB_BINARY_DIR ${CMAKE_BINARY_DIR}/lib ABSOLUTE) get_filename_component(LAMMPS_LIB_BINARY_DIR ${CMAKE_BINARY_DIR}/lib ABSOLUTE)
# collect all executables and shared libs in the top level build folder # collect all executables and shared libs in the top level build folder
@ -208,7 +209,7 @@ else()
unset(CMAKE_CXX_CLANG_TIDY CACHE) unset(CMAKE_CXX_CLANG_TIDY CACHE)
endif() endif()
include(GNUInstallDirs)
file(GLOB ALL_SOURCES CONFIGURE_DEPENDS ${LAMMPS_SOURCE_DIR}/[^.]*.cpp) file(GLOB ALL_SOURCES CONFIGURE_DEPENDS ${LAMMPS_SOURCE_DIR}/[^.]*.cpp)
file(GLOB MAIN_SOURCES CONFIGURE_DEPENDS ${LAMMPS_SOURCE_DIR}/main.cpp) file(GLOB MAIN_SOURCES CONFIGURE_DEPENDS ${LAMMPS_SOURCE_DIR}/main.cpp)
list(REMOVE_ITEM ALL_SOURCES ${MAIN_SOURCES}) list(REMOVE_ITEM ALL_SOURCES ${MAIN_SOURCES})
@ -256,6 +257,7 @@ set(STANDARD_PACKAGES
DRUDE DRUDE
EFF EFF
ELECTRODE ELECTRODE
EXTRA-COMMAND
EXTRA-COMPUTE EXTRA-COMPUTE
EXTRA-DUMP EXTRA-DUMP
EXTRA-FIX EXTRA-FIX
@ -281,10 +283,11 @@ set(STANDARD_PACKAGES
ML-HDNNP ML-HDNNP
ML-IAP ML-IAP
ML-PACE ML-PACE
ML-POD
ML-QUIP ML-QUIP
ML-RANN ML-RANN
ML-SNAP ML-SNAP
ML-POD ML-UF3
MOFFF MOFFF
MOLECULE MOLECULE
MOLFILE MOLFILE
@ -689,7 +692,7 @@ endif()
# packages which selectively include variants based on enabled styles # packages which selectively include variants based on enabled styles
# e.g. accelerator packages # e.g. accelerator packages
###################################################################### ######################################################################
foreach(PKG_WITH_INCL CORESHELL DPD-SMOOTH MC MISC PHONON QEQ OPENMP KOKKOS OPT INTEL GPU) foreach(PKG_WITH_INCL CORESHELL DPD-BASIC DPD-SMOOTH MC MISC PHONON QEQ OPENMP KOKKOS OPT INTEL GPU)
if(PKG_${PKG_WITH_INCL}) if(PKG_${PKG_WITH_INCL})
include(Packages/${PKG_WITH_INCL}) include(Packages/${PKG_WITH_INCL})
endif() endif()

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@ -1,6 +1,6 @@
message(STATUS "Downloading and building OpenCL loader library") message(STATUS "Downloading and building OpenCL loader library")
set(OPENCL_LOADER_URL "${LAMMPS_THIRDPARTY_URL}/opencl-loader-2024.02.09.tar.gz" CACHE STRING "URL for OpenCL loader tarball") set(OPENCL_LOADER_URL "${LAMMPS_THIRDPARTY_URL}/opencl-loader-2024.05.09.tar.gz" CACHE STRING "URL for OpenCL loader tarball")
set(OPENCL_LOADER_MD5 "f3573cf9daa3558ba46fd5866517f38f" CACHE STRING "MD5 checksum of OpenCL loader tarball") set(OPENCL_LOADER_MD5 "e7796826b21c059224fabe997e0f2075" CACHE STRING "MD5 checksum of OpenCL loader tarball")
mark_as_advanced(OPENCL_LOADER_URL) mark_as_advanced(OPENCL_LOADER_URL)
mark_as_advanced(OPENCL_LOADER_MD5) mark_as_advanced(OPENCL_LOADER_MD5)

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@ -0,0 +1,9 @@
# pair style dpd/coul/slater/long may only be installed if also KSPACE is installed
if(NOT PKG_KSPACE)
get_property(LAMMPS_PAIR_HEADERS GLOBAL PROPERTY PAIR)
list(REMOVE_ITEM LAMMPS_PAIR_HEADERS ${LAMMPS_SOURCE_DIR}/DPD-BASIC/pair_dpd_coul_slater_long.h)
set_property(GLOBAL PROPERTY PAIR "${LAMMPS_PAIR_HEADERS}")
get_target_property(LAMMPS_SOURCES lammps SOURCES)
list(REMOVE_ITEM LAMMPS_SOURCES ${LAMMPS_SOURCE_DIR}/DPD-BASIC/pair_dpd_coul_slater_long.cpp)
set_property(TARGET lammps PROPERTY SOURCES "${LAMMPS_SOURCES}")
endif()

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@ -45,8 +45,8 @@ if(DOWNLOAD_KOKKOS)
list(APPEND KOKKOS_LIB_BUILD_ARGS "-DCMAKE_CXX_EXTENSIONS=${CMAKE_CXX_EXTENSIONS}") list(APPEND KOKKOS_LIB_BUILD_ARGS "-DCMAKE_CXX_EXTENSIONS=${CMAKE_CXX_EXTENSIONS}")
list(APPEND KOKKOS_LIB_BUILD_ARGS "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}") list(APPEND KOKKOS_LIB_BUILD_ARGS "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}")
include(ExternalProject) include(ExternalProject)
set(KOKKOS_URL "https://github.com/kokkos/kokkos/archive/4.3.00.tar.gz" CACHE STRING "URL for KOKKOS tarball") set(KOKKOS_URL "https://github.com/kokkos/kokkos/archive/4.3.01.tar.gz" CACHE STRING "URL for KOKKOS tarball")
set(KOKKOS_MD5 "889dcea2b5ced3debdc5b0820044bdc4" CACHE STRING "MD5 checksum of KOKKOS tarball") set(KOKKOS_MD5 "243de871b3dc2cf3990c1c404032df83" CACHE STRING "MD5 checksum of KOKKOS tarball")
mark_as_advanced(KOKKOS_URL) mark_as_advanced(KOKKOS_URL)
mark_as_advanced(KOKKOS_MD5) mark_as_advanced(KOKKOS_MD5)
GetFallbackURL(KOKKOS_URL KOKKOS_FALLBACK) GetFallbackURL(KOKKOS_URL KOKKOS_FALLBACK)
@ -71,7 +71,7 @@ if(DOWNLOAD_KOKKOS)
add_dependencies(LAMMPS::KOKKOSCORE kokkos_build) add_dependencies(LAMMPS::KOKKOSCORE kokkos_build)
add_dependencies(LAMMPS::KOKKOSCONTAINERS kokkos_build) add_dependencies(LAMMPS::KOKKOSCONTAINERS kokkos_build)
elseif(EXTERNAL_KOKKOS) elseif(EXTERNAL_KOKKOS)
find_package(Kokkos 4.3.00 REQUIRED CONFIG) find_package(Kokkos 4.3.01 REQUIRED CONFIG)
target_link_libraries(lammps PRIVATE Kokkos::kokkos) target_link_libraries(lammps PRIVATE Kokkos::kokkos)
else() else()
set(LAMMPS_LIB_KOKKOS_SRC_DIR ${LAMMPS_LIB_SOURCE_DIR}/kokkos) set(LAMMPS_LIB_KOKKOS_SRC_DIR ${LAMMPS_LIB_SOURCE_DIR}/kokkos)

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@ -1,5 +1,9 @@
# Plumed2 support for PLUMED package # Plumed2 support for PLUMED package
# for supporting multiple concurrent plumed2 installations for debugging and testing
set(PLUMED_SUFFIX "" CACHE STRING "Suffix for Plumed2 library")
mark_as_advanced(PLUMED_SUFFIX)
if(BUILD_MPI) if(BUILD_MPI)
set(PLUMED_CONFIG_MPI "--enable-mpi") set(PLUMED_CONFIG_MPI "--enable-mpi")
set(PLUMED_CONFIG_CC ${CMAKE_MPI_C_COMPILER}) set(PLUMED_CONFIG_CC ${CMAKE_MPI_C_COMPILER})
@ -21,9 +25,11 @@ else()
set(PLUMED_CONFIG_OMP "--disable-openmp") set(PLUMED_CONFIG_OMP "--disable-openmp")
endif() endif()
set(PLUMED_URL "https://github.com/plumed/plumed2/releases/download/v2.8.3/plumed-src-2.8.3.tgz" # Note: must also adjust check for supported API versions in
# fix_plumed.cpp when version changes from v2.n.x to v2.n+1.y
set(PLUMED_URL "https://github.com/plumed/plumed2/releases/download/v2.9.1/plumed-src-2.9.1.tgz"
CACHE STRING "URL for PLUMED tarball") CACHE STRING "URL for PLUMED tarball")
set(PLUMED_MD5 "76d23cd394eba9e6530316ed1184e219" CACHE STRING "MD5 checksum of PLUMED tarball") set(PLUMED_MD5 "c3b2d31479c1e9ce211719d40e9efbd7" CACHE STRING "MD5 checksum of PLUMED tarball")
mark_as_advanced(PLUMED_URL) mark_as_advanced(PLUMED_URL)
mark_as_advanced(PLUMED_MD5) mark_as_advanced(PLUMED_MD5)
@ -151,15 +157,15 @@ else()
file(MAKE_DIRECTORY ${INSTALL_DIR}/include) file(MAKE_DIRECTORY ${INSTALL_DIR}/include)
else() else()
find_package(PkgConfig REQUIRED) find_package(PkgConfig REQUIRED)
pkg_check_modules(PLUMED REQUIRED plumed) pkg_check_modules(PLUMED REQUIRED plumed${PLUMED_SUFFIX})
add_library(LAMMPS::PLUMED INTERFACE IMPORTED) add_library(LAMMPS::PLUMED INTERFACE IMPORTED)
if(PLUMED_MODE STREQUAL "STATIC") if(PLUMED_MODE STREQUAL "STATIC")
include(${PLUMED_LIBDIR}/plumed/src/lib/Plumed.cmake.static) include(${PLUMED_LIBDIR}/plumed${PLUMED_SUFFIX}/src/lib/Plumed.cmake.static)
elseif(PLUMED_MODE STREQUAL "SHARED") elseif(PLUMED_MODE STREQUAL "SHARED")
include(${PLUMED_LIBDIR}/plumed/src/lib/Plumed.cmake.shared) include(${PLUMED_LIBDIR}/plumed${PLUMED_SUFFIX}/src/lib/Plumed.cmake.shared)
elseif(PLUMED_MODE STREQUAL "RUNTIME") elseif(PLUMED_MODE STREQUAL "RUNTIME")
set_target_properties(LAMMPS::PLUMED PROPERTIES INTERFACE_COMPILE_DEFINITIONS "__PLUMED_DEFAULT_KERNEL=${PLUMED_LIBDIR}/${CMAKE_SHARED_LIBRARY_PREFIX}plumedKernel${CMAKE_SHARED_LIBRARY_SUFFIX}") set_target_properties(LAMMPS::PLUMED PROPERTIES INTERFACE_COMPILE_DEFINITIONS "__PLUMED_DEFAULT_KERNEL=${PLUMED_LIBDIR}/${CMAKE_SHARED_LIBRARY_PREFIX}plumed${PLUMED_SUFFIX}Kernel${CMAKE_SHARED_LIBRARY_SUFFIX}")
include(${PLUMED_LIBDIR}/plumed/src/lib/Plumed.cmake.runtime) include(${PLUMED_LIBDIR}/plumed${PLUMED_SUFFIX}/src/lib/Plumed.cmake.runtime)
endif() endif()
set_target_properties(LAMMPS::PLUMED PROPERTIES INTERFACE_LINK_LIBRARIES "${PLUMED_LOAD}") set_target_properties(LAMMPS::PLUMED PROPERTIES INTERFACE_LINK_LIBRARIES "${PLUMED_LOAD}")
set_target_properties(LAMMPS::PLUMED PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${PLUMED_INCLUDE_DIRS}") set_target_properties(LAMMPS::PLUMED PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${PLUMED_INCLUDE_DIRS}")

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@ -59,12 +59,14 @@ done
echo "Set up wrapper script" echo "Set up wrapper script"
MYDIR=$(dirname "$0") MYDIR=$(dirname "$0")
cp ${MYDIR}/xdg-open ${DESTDIR}/bin
cp ${MYDIR}/linux_wrapper.sh ${DESTDIR}/bin cp ${MYDIR}/linux_wrapper.sh ${DESTDIR}/bin
for s in ${DESTDIR}/bin/* for s in ${DESTDIR}/bin/*
do \ do \
EXE=$(basename $s) EXE=$(basename $s)
test ${EXE} = linux_wrapper.sh && continue test ${EXE} = linux_wrapper.sh && continue
test ${EXE} = qt.conf && continue test ${EXE} = qt.conf && continue
test ${EXE} = xdg-open && continue
ln -s bin/linux_wrapper.sh ${DESTDIR}/${EXE} ln -s bin/linux_wrapper.sh ${DESTDIR}/${EXE}
done done

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@ -4,15 +4,17 @@
# reset locale to avoid problems with decimal numbers # reset locale to avoid problems with decimal numbers
export LC_ALL=C export LC_ALL=C
BASEDIR=$(dirname "$0") BASEDIR="$(dirname "$0")"
EXENAME=$(basename "$0") EXENAME="$(basename "$0")"
PATH="${BASEDIR}/bin:${PATH}"
# append to LD_LIBRARY_PATH to prefer local (newer) libs # append to LD_LIBRARY_PATH to prefer local (newer) libs
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${BASEDIR}/lib LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:${BASEDIR}/lib"
# set some environment variables for LAMMPS etc. # set some environment variables for LAMMPS etc.
LAMMPS_POTENTIALS=${BASEDIR}/share/lammps/potentials LAMMPS_POTENTIALS="${BASEDIR}/share/lammps/potentials"
MSI2LMP_LIBRARY=${BASEDIR}/share/lammps/frc_files MSI2LMP_LIBRARY="${BASEDIR}/share/lammps/frc_files"
export LD_LIBRARY_PATH LAMMPS_POTENTIALS MSI2LMP_LIBRARY export LD_LIBRARY_PATH LAMMPS_POTENTIALS MSI2LMP_LIBRARY PATH
exec "${BASEDIR}/bin/${EXENAME}" "$@" exec "${BASEDIR}/bin/${EXENAME}" "$@"

1074
cmake/packaging/xdg-open Executable file

File diff suppressed because it is too large Load Diff

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@ -26,8 +26,9 @@ set(ALL_PACKAGES
DPD-REACT DPD-REACT
DPD-SMOOTH DPD-SMOOTH
DRUDE DRUDE
ELECTRODE
EFF EFF
ELECTRODE
EXTRA-COMMAND
EXTRA-COMPUTE EXTRA-COMPUTE
EXTRA-DUMP EXTRA-DUMP
EXTRA-FIX EXTRA-FIX
@ -60,6 +61,7 @@ set(ALL_PACKAGES
ML-QUIP ML-QUIP
ML-RANN ML-RANN
ML-SNAP ML-SNAP
ML-UF3
MOFFF MOFFF
MOLECULE MOLECULE
MOLFILE MOLFILE

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@ -28,8 +28,9 @@ set(ALL_PACKAGES
DPD-REACT DPD-REACT
DPD-SMOOTH DPD-SMOOTH
DRUDE DRUDE
ELECTRODE
EFF EFF
ELECTRODE
EXTRA-COMMAND
EXTRA-COMPUTE EXTRA-COMPUTE
EXTRA-DUMP EXTRA-DUMP
EXTRA-FIX EXTRA-FIX
@ -62,6 +63,7 @@ set(ALL_PACKAGES
ML-QUIP ML-QUIP
ML-RANN ML-RANN
ML-SNAP ML-SNAP
ML-UF3
MOFFF MOFFF
MOLECULE MOLECULE
MOLFILE MOLFILE

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@ -22,8 +22,9 @@ set(WIN_PACKAGES
DPD-REACT DPD-REACT
DPD-SMOOTH DPD-SMOOTH
DRUDE DRUDE
ELECTRODE
EFF EFF
ELECTRODE
EXTRA-COMMAND
EXTRA-COMPUTE EXTRA-COMPUTE
EXTRA-DUMP EXTRA-DUMP
EXTRA-FIX EXTRA-FIX
@ -32,7 +33,6 @@ set(WIN_PACKAGES
FEP FEP
GPU GPU
GRANULAR GRANULAR
INTEL
INTERLAYER INTERLAYER
KSPACE KSPACE
LEPTON LEPTON
@ -50,6 +50,7 @@ set(WIN_PACKAGES
ML-POD ML-POD
ML-RANN ML-RANN
ML-SNAP ML-SNAP
ML-UF3
MOFFF MOFFF
MOLECULE MOLECULE
MOLFILE MOLFILE

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@ -26,6 +26,7 @@ set(ALL_PACKAGES
DRUDE DRUDE
EFF EFF
ELECTRODE ELECTRODE
EXTRA-COMMAND
EXTRA-COMPUTE EXTRA-COMPUTE
EXTRA-DUMP EXTRA-DUMP
EXTRA-FIX EXTRA-FIX
@ -45,6 +46,7 @@ set(ALL_PACKAGES
ML-IAP ML-IAP
ML-POD ML-POD
ML-SNAP ML-SNAP
ML-UF3
MOFFF MOFFF
MOLECULE MOLECULE
OPENMP OPENMP

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@ -22,6 +22,7 @@ set(WIN_PACKAGES
DRUDE DRUDE
EFF EFF
ELECTRODE ELECTRODE
EXTRA-COMMAND
EXTRA-COMPUTE EXTRA-COMPUTE
EXTRA-DUMP EXTRA-DUMP
EXTRA-FIX EXTRA-FIX
@ -42,6 +43,7 @@ set(WIN_PACKAGES
ML-IAP ML-IAP
ML-POD ML-POD
ML-SNAP ML-SNAP
ML-UF3
MOFFF MOFFF
MOLECULE MOLECULE
MOLFILE MOLFILE
@ -50,8 +52,8 @@ set(WIN_PACKAGES
ORIENT ORIENT
PERI PERI
PHONON PHONON
POEMS
PLUGIN PLUGIN
POEMS
PTM PTM
QEQ QEQ
QTB QTB

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@ -1,7 +1,7 @@
.TH LAMMPS "1" "17 April 2024" "2024-04-17" .TH LAMMPS "1" "27 June 2024" "2024-06-27"
.SH NAME .SH NAME
.B LAMMPS .B LAMMPS
\- Molecular Dynamics Simulator. Version 17 April 2024 \- Molecular Dynamics Simulator. Version 27 June 2024
.SH SYNOPSIS .SH SYNOPSIS
.B lmp .B lmp

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@ -27,7 +27,7 @@ OPT.
* :doc:`none <bond_none>` * :doc:`none <bond_none>`
* :doc:`zero <bond_zero>` * :doc:`zero <bond_zero>`
* :doc:`hybrid <bond_hybrid>` * :doc:`hybrid (k) <bond_hybrid>`
* *
* *
* *

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@ -108,6 +108,10 @@ KOKKOS, o = OPENMP, t = OPT.
* :doc:`pe/mol/tally <compute_tally>` * :doc:`pe/mol/tally <compute_tally>`
* :doc:`pe/tally <compute_tally>` * :doc:`pe/tally <compute_tally>`
* :doc:`plasticity/atom <compute_plasticity_atom>` * :doc:`plasticity/atom <compute_plasticity_atom>`
* :doc:`pod/atom <compute_pod_atom>`
* :doc:`podd/atom <compute_pod_atom>`
* :doc:`pod/local <compute_pod_atom>`
* :doc:`pod/global <compute_pod_atom>`
* :doc:`pressure <compute_pressure>` * :doc:`pressure <compute_pressure>`
* :doc:`pressure/alchemy <compute_pressure_alchemy>` * :doc:`pressure/alchemy <compute_pressure_alchemy>`
* :doc:`pressure/uef <compute_pressure_uef>` * :doc:`pressure/uef <compute_pressure_uef>`

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@ -25,16 +25,16 @@ OPT.
* :doc:`none <pair_none>` * :doc:`none <pair_none>`
* :doc:`zero <pair_zero>` * :doc:`zero <pair_zero>`
* :doc:`hybrid (k) <pair_hybrid>` * :doc:`hybrid (ko) <pair_hybrid>`
* :doc:`hybrid/overlay (k) <pair_hybrid>` * :doc:`hybrid/molecular (o) <pair_hybrid>`
* :doc:`hybrid/scaled <pair_hybrid>` * :doc:`hybrid/overlay (ko) <pair_hybrid>`
* :doc:`hybrid/scaled (o) <pair_hybrid>`
* :doc:`kim <pair_kim>` * :doc:`kim <pair_kim>`
* :doc:`list <pair_list>` * :doc:`list <pair_list>`
* :doc:`tracker <pair_tracker>` * :doc:`tracker <pair_tracker>`
* *
* *
* *
*
* :doc:`adp (ko) <pair_adp>` * :doc:`adp (ko) <pair_adp>`
* :doc:`agni (o) <pair_agni>` * :doc:`agni (o) <pair_agni>`
* :doc:`aip/water/2dm (t) <pair_aip_water_2dm>` * :doc:`aip/water/2dm (t) <pair_aip_water_2dm>`
@ -94,9 +94,10 @@ OPT.
* :doc:`coul/wolf (ko) <pair_coul>` * :doc:`coul/wolf (ko) <pair_coul>`
* :doc:`coul/wolf/cs <pair_cs>` * :doc:`coul/wolf/cs <pair_cs>`
* :doc:`dpd (giko) <pair_dpd>` * :doc:`dpd (giko) <pair_dpd>`
* :doc:`dpd/fdt <pair_dpd_fdt>` * :doc:`dpd/coul/slater/long (g) <pair_dpd_coul_slater_long>`
* :doc:`dpd/ext (ko) <pair_dpd_ext>` * :doc:`dpd/ext (ko) <pair_dpd_ext>`
* :doc:`dpd/ext/tstat (ko) <pair_dpd_ext>` * :doc:`dpd/ext/tstat (ko) <pair_dpd_ext>`
* :doc:`dpd/fdt <pair_dpd_fdt>`
* :doc:`dpd/fdt/energy (k) <pair_dpd_fdt>` * :doc:`dpd/fdt/energy (k) <pair_dpd_fdt>`
* :doc:`dpd/tstat (gko) <pair_dpd>` * :doc:`dpd/tstat (gko) <pair_dpd>`
* :doc:`dsmc <pair_dsmc>` * :doc:`dsmc <pair_dsmc>`
@ -246,7 +247,7 @@ OPT.
* :doc:`pace (k) <pair_pace>` * :doc:`pace (k) <pair_pace>`
* :doc:`pace/extrapolation (k) <pair_pace>` * :doc:`pace/extrapolation (k) <pair_pace>`
* :doc:`pedone (o) <pair_pedone>` * :doc:`pedone (o) <pair_pedone>`
* :doc:`pod <pair_pod>` * :doc:`pod (k) <pair_pod>`
* :doc:`peri/eps <pair_peri>` * :doc:`peri/eps <pair_peri>`
* :doc:`peri/lps (o) <pair_peri>` * :doc:`peri/lps (o) <pair_peri>`
* :doc:`peri/pmb (o) <pair_peri>` * :doc:`peri/pmb (o) <pair_peri>`
@ -269,7 +270,7 @@ OPT.
* :doc:`smd/ulsph <pair_smd_ulsph>` * :doc:`smd/ulsph <pair_smd_ulsph>`
* :doc:`smtbq <pair_smtbq>` * :doc:`smtbq <pair_smtbq>`
* :doc:`snap (ik) <pair_snap>` * :doc:`snap (ik) <pair_snap>`
* :doc:`soft (go) <pair_soft>` * :doc:`soft (gko) <pair_soft>`
* :doc:`sph/heatconduction (g) <pair_sph_heatconduction>` * :doc:`sph/heatconduction (g) <pair_sph_heatconduction>`
* :doc:`sph/idealgas <pair_sph_idealgas>` * :doc:`sph/idealgas <pair_sph_idealgas>`
* :doc:`sph/lj (g) <pair_sph_lj>` * :doc:`sph/lj (g) <pair_sph_lj>`
@ -303,6 +304,7 @@ OPT.
* :doc:`tip4p/long/soft (o) <pair_fep_soft>` * :doc:`tip4p/long/soft (o) <pair_fep_soft>`
* :doc:`tri/lj <pair_tri_lj>` * :doc:`tri/lj <pair_tri_lj>`
* :doc:`ufm (got) <pair_ufm>` * :doc:`ufm (got) <pair_ufm>`
* :doc:`uf3 (k) <pair_uf3>`
* :doc:`vashishta (gko) <pair_vashishta>` * :doc:`vashishta (gko) <pair_vashishta>`
* :doc:`vashishta/table (o) <pair_vashishta>` * :doc:`vashishta/table (o) <pair_vashishta>`
* :doc:`wf/cut <pair_wf_cut>` * :doc:`wf/cut <pair_wf_cut>`

View File

@ -148,6 +148,14 @@ performance characteristics on NVIDIA GPUs. Both, the KOKKOS
and the :ref:`GPU package <PKG-GPU>` are maintained and the :ref:`GPU package <PKG-GPU>` are maintained
and allow running LAMMPS with GPU acceleration. and allow running LAMMPS with GPU acceleration.
i-PI tool
---------
.. versionchanged:: 27June2024
The i-PI tool has been removed from the LAMMPS distribution. Instead,
instructions to install i-PI from PyPI via pip are provided.
restart2data tool restart2data tool
----------------- -----------------

View File

@ -211,6 +211,9 @@ Argument processing
.. doxygenfunction:: bounds .. doxygenfunction:: bounds
:project: progguide :project: progguide
.. doxygenfunction:: bounds_typelabel
:project: progguide
.. doxygenfunction:: expand_args .. doxygenfunction:: expand_args
:project: progguide :project: progguide

View File

@ -50,6 +50,30 @@ We are looking at the following cases:
- `Case 3: a potential requiring communication`_ - `Case 3: a potential requiring communication`_
- `Case 4: potentials without a compute() function`_ - `Case 4: potentials without a compute() function`_
Package and build system considerations
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In general, new pair styles should be added to the :ref:`EXTRA-PAIR
package <PKG-EXTRA-PAIR>` unless they are an accelerated pair style and
then they should be added to the corresponding accelerator package
(:ref:`GPU <PKG-GPU>`, :ref:`INTEL <PKG-INTEL>`, :ref:`KOKKOS
<PKG-KOKKOS>`, :ref:`OPENMP <PKG-OPENMP>`, :ref:`OPT <PKG-OPT>`). If
you feel that your contribution should be added to a different package,
please consult with the LAMMPS developers first.
The contributed code needs to support the :doc:`traditional GNU make
build process <Build_make>` **and** the :doc:`CMake build process
<Build_cmake>`. For the GNU make process and if the package has an
``Install.sh`` file, most likely that file needs to be updated to
correctly copy the sources when installing the package and properly
delete them when uninstalling. This is particularly important when
added a new pair style that is a derived class from an existing pair
style in a package, so that its installation depends on the the
installation status of the package of the derived class. For the CMake
process, it is sometimes necessary to make changes to the package
specific CMake scripting in ``cmake/Modules/Packages``.
---- ----
Case 1: a pairwise additive model Case 1: a pairwise additive model

View File

@ -305,6 +305,8 @@ of the contents of the :f:mod:`LIBLAMMPS` Fortran interface to LAMMPS.
:ftype extract_setting: function :ftype extract_setting: function
:f extract_global: :f:func:`extract_global` :f extract_global: :f:func:`extract_global`
:ftype extract_global: function :ftype extract_global: function
:f map_atom: :f:func:`map_atom`
:ftype map_atom: function
:f extract_atom: :f:func:`extract_atom` :f extract_atom: :f:func:`extract_atom`
:ftype extract_atom: function :ftype extract_atom: function
:f extract_compute: :f:func:`extract_compute` :f extract_compute: :f:func:`extract_compute`

View File

@ -1,6 +1,10 @@
CHARMM, AMBER, COMPASS, and DREIDING force fields CHARMM, AMBER, COMPASS, and DREIDING force fields
================================================= =================================================
A compact summary of the concepts, definitions, and properties of
force fields with explicit bonded interactions (like the ones discussed
in this HowTo) is given in :ref:`(Gissinger) <Typelabel2>`.
A force field has 2 parts: the formulas that define it and the A force field has 2 parts: the formulas that define it and the
coefficients used for a particular system. Here we only discuss coefficients used for a particular system. Here we only discuss
formulas implemented in LAMMPS that correspond to formulas commonly used formulas implemented in LAMMPS that correspond to formulas commonly used
@ -11,12 +15,42 @@ commands like :doc:`pair_coeff <pair_coeff>` or :doc:`bond_coeff
<bond_coeff>` and so on. See the :doc:`Tools <Tools>` doc page for <bond_coeff>` and so on. See the :doc:`Tools <Tools>` doc page for
additional tools that can use CHARMM, AMBER, or Materials Studio additional tools that can use CHARMM, AMBER, or Materials Studio
generated files to assign force field coefficients and convert their generated files to assign force field coefficients and convert their
output into LAMMPS input. output into LAMMPS input. LAMMPS input scripts can also be generated by
`charmm-gui.org <https://charmm-gui.org/>`_.
See :ref:`(MacKerell) <howto-MacKerell>` for a description of the CHARMM CHARMM and AMBER
force field. See :ref:`(Cornell) <howto-Cornell>` for a description of ----------------
the AMBER force field. See :ref:`(Sun) <howto-Sun>` for a description
of the COMPASS force field. The `CHARMM force field
<https://mackerell.umaryland.edu/charmm_ff.shtml>`_ :ref:`(MacKerell)
<howto-MacKerell>` and `AMBER force field
<https://ambermd.org/AmberModels.php>`_ :ref:`(Cornell) <howto-Cornell>`
have potential energy function of the form
.. math::
V & = \sum_{bonds} E_b + \sum_{angles} \!E_a + \!\overbrace{\sum_{dihedral} \!\!E_d}^{\substack{
\text{charmm} \\
\text{charmmfsw}
}} +\!\!\! \sum_{impropers} \!\!\!E_i \\[.6em]
& \quad + \!\!\!\!\!\!\!\!\!\!\underbrace{~\sum_{pairs} \left(E_{LJ}+E_{coul}\right)}_{\substack{
\text{lj/charmm/coul/charmm} \\
\text{lj/charmm/coul/charmm/implicit} \\
\text{lj/charmm/coul/long} \\
\text{lj/charmm/coul/msm} \\
\text{lj/charmmfsw/coul/charmmfsh} \\
\text{lj/charmmfsw/coul/long}
}} \!\!\!\!\!\!\!\!+ \!\!\sum_{special}\! E_s + \!\!\!\!\sum_{residues} \!\!\!{\scriptstyle\mathrm{CMAP}(\phi,\psi)}
The terms are computed by bond styles (relationship between 2 atoms),
angle styles (between 3 atoms) , dihedral/improper styles (between 4
atoms), pair styles (non-covalently bonded pair interactions) and
special bonds. The CMAP term (see :doc:`fix cmap <fix_cmap>` command for
details) corrects for pairs of dihedral angles ("Correction MAP") to
significantly improve the structural and dynamic properties of proteins
in crystalline and solution environments :ref:`(Brooks)
<howto-Brooks>`. The AMBER force field does not include the CMAP term.
The interaction styles listed below compute force field formulas that The interaction styles listed below compute force field formulas that
are consistent with common options in CHARMM or AMBER. See each are consistent with common options in CHARMM or AMBER. See each
@ -31,10 +65,81 @@ command's documentation for the formula it computes.
* :doc:`pair_style <pair_charmm>` lj/charmm/coul/charmm * :doc:`pair_style <pair_charmm>` lj/charmm/coul/charmm
* :doc:`pair_style <pair_charmm>` lj/charmm/coul/charmm/implicit * :doc:`pair_style <pair_charmm>` lj/charmm/coul/charmm/implicit
* :doc:`pair_style <pair_charmm>` lj/charmm/coul/long * :doc:`pair_style <pair_charmm>` lj/charmm/coul/long
* :doc:`special_bonds <special_bonds>` charmm * :doc:`special_bonds <special_bonds>` charmm
* :doc:`special_bonds <special_bonds>` amber * :doc:`special_bonds <special_bonds>` amber
The pair styles compute Lennard Jones (LJ) and Coulombic interactions
with additional switching or shifting functions that ramp the energy
and/or force smoothly to zero between an inner :math:`(a)` and outer
:math:`(b)` cutoff. The older styles with *charmm* (not *charmmfsw* or
*charmmfsh*\ ) in their name compute the LJ and Coulombic interactions
with an energy switching function (esw) S(r) which ramps the energy
smoothly to zero between the inner and outer cutoff. This can cause
irregularities in pairwise forces (due to the discontinuous second
derivative of energy at the boundaries of the switching region), which
in some cases can result in complications in energy minimization and
detectable artifacts in MD simulations.
.. grid:: 1 1 2 2
.. grid-item::
.. math::
LJ(r) &= 4 \epsilon \left[ \left(\frac{\sigma}{r}\right)^{12} -
\left(\frac{\sigma}{r}\right)^6 \right]\\[.6em]
C(r) &= \frac{C q_i q_j}{ \epsilon r}\\[.6em]
S(r) &= \frac{ \left(b^2 - r^2\right)^2 \left(b^2 + 2r^2 - 3{a^2}\right)}
{ \left(b^2 - a^2\right)^3 }\\[.6em]
E_{LJ}(r) &= \begin{cases}
LJ(r), & r \leq a \\
LJ(r) S(r), & a < r \leq b \\
0, &r > b
\end{cases} \\[.6em]
E_{coul}(r) &= \begin{cases}
C(r), & r \leq a \\
C(r) S(r), & a < r \leq b \\
0, & r > b
\end{cases}
.. grid-item::
.. image:: img/howto_charmm_ELJ.png
:align: center
The newer styles with *charmmfsw* or *charmmfsh* in their name replace
energy switching with force switching (fsw) for LJ interactions and
force shifting (fsh) functions for Coulombic interactions
:ref:`(Steinbach) <howto-Steinbach>`
.. grid:: 1 1 2 2
.. grid-item::
.. math::
E_{LJ}(r) = & \begin{cases}
4 \epsilon \sigma^6 \left(\frac{\displaystyle\sigma
^6-r^6}{\displaystyle r^{12}}-\frac{\displaystyle\sigma ^6}{\displaystyle a^6
b^6}+\frac{\displaystyle 1}{\displaystyle a^3 b^3}\right) & r\leq a \\
\frac{\displaystyle 4 \epsilon \sigma^6 \left(\sigma ^6
\left(b^6-r^6\right)^2-b^3 r^6 \left(a^3+b^3\right)
\left(b^3-r^3\right)^2\right)}{\displaystyle b^6 r^{12}
\left(b^6-a^6\right)} & a<r \leq b\\
0, & r>b
\end{cases}\\[.6em]
E_{coul}(r) & = \begin{cases}
C(r) \frac{\displaystyle (b-r)^2}{\displaystyle r b^2}, & r \leq b \\
0, & r > b
\end{cases}
.. grid-item::
.. image:: img/howto_charmmfsw_ELJ.png
:align: center
These styles are used by LAMMPS input scripts generated by
https://charmm-gui.org/ :ref:`(Brooks) <howto-Brooks>`.
.. note:: .. note::
For CHARMM, newer *charmmfsw* or *charmmfsh* styles were released in For CHARMM, newer *charmmfsw* or *charmmfsh* styles were released in
@ -43,17 +148,33 @@ command's documentation for the formula it computes.
<pair_charmm>` and :doc:`dihedral charmm <dihedral_charmm>` doc <pair_charmm>` and :doc:`dihedral charmm <dihedral_charmm>` doc
pages. pages.
.. note::
The TIP3P water model is strongly recommended for use with the CHARMM
force field. In fact, `"using the SPC model with CHARMM parameters is
a bad idea"
<https://matsci.org/t/using-spc-water-with-charmm-ff/24715>`_ and `"to
enable TIP4P style water in CHARMM, you would have to write a new pair
style"
<https://matsci.org/t/hybrid-pair-styles-for-charmm-and-tip4p-ew/32609>`_
. LAMMPS input scripts generated by Solution Builder on https://charmm-gui.org
use TIP3P molecules for solvation. Any other water model can and
probably will lead to false conclusions.
COMPASS
-------
COMPASS is a general force field for atomistic simulation of common COMPASS is a general force field for atomistic simulation of common
organic molecules, inorganic small molecules, and polymers which was organic molecules, inorganic small molecules, and polymers which was
developed using ab initio and empirical parameterization techniques. developed using ab initio and empirical parameterization techniques
See the :doc:`Tools <Tools>` page for the msi2lmp tool for creating :ref:`(Sun) <howto-Sun>`. See the :doc:`Tools <Tools>` page for the
LAMMPS template input and data files from BIOVIA's Materials Studio msi2lmp tool for creating LAMMPS template input and data files from
files. Please note that the msi2lmp tool is very old and largely BIOVIA's Materials Studio files. Please note that the msi2lmp tool is
unmaintained, so it does not support all features of Materials Studio very old and largely unmaintained, so it does not support all features
provided force field files, especially additions during the last decade. of Materials Studio provided force field files, especially additions
You should watch the output carefully and compare results, where during the last decade. You should watch the output carefully and
possible. See :ref:`(Sun) <howto-Sun>` for a description of the COMPASS force compare results, where possible. See :ref:`(Sun) <howto-Sun>` for a
field. description of the COMPASS force field.
These interaction styles listed below compute force field formulas that These interaction styles listed below compute force field formulas that
are consistent with the COMPASS force field. See each command's are consistent with the COMPASS force field. See each command's
@ -70,14 +191,21 @@ documentation for the formula it computes.
* :doc:`special_bonds <special_bonds>` lj/coul 0 0 1 * :doc:`special_bonds <special_bonds>` lj/coul 0 0 1
DREIDING is a generic force field developed by the `Goddard group <http://www.wag.caltech.edu>`_ at Caltech and is useful for DREIDING
predicting structures and dynamics of organic, biological and main-group --------
inorganic molecules. The philosophy in DREIDING is to use general force
constants and geometry parameters based on simple hybridization DREIDING is a generic force field developed by the `Goddard group
considerations, rather than individual force constants and geometric <http://www.wag.caltech.edu>`_ at Caltech and is useful for predicting
parameters that depend on the particular combinations of atoms involved structures and dynamics of organic, biological and main-group inorganic
in the bond, angle, or torsion terms. DREIDING has an :doc:`explicit hydrogen bond term <pair_hbond_dreiding>` to describe interactions involving a molecules. The philosophy in DREIDING is to use general force constants
hydrogen atom on very electronegative atoms (N, O, F). and geometry parameters based on simple hybridization considerations,
rather than individual force constants and geometric parameters that
depend on the particular combinations of atoms involved in the bond,
angle, or torsion terms. DREIDING has an :doc:`explicit hydrogen bond
term <pair_hbond_dreiding>` to describe interactions involving a
hydrogen atom on very electronegative atoms (N, O, F). Unlike CHARMM
or AMBER, the DREIDING force field has not been parameterized for
considering solvents (like water).
See :ref:`(Mayo) <howto-Mayo>` for a description of the DREIDING force field See :ref:`(Mayo) <howto-Mayo>` for a description of the DREIDING force field
@ -110,21 +238,31 @@ documentation for the formula it computes.
---------- ----------
.. _Typelabel2:
**(Gissinger)** J. R. Gissinger, I. Nikiforov, Y. Afshar, B. Waters, M. Choi, D. S. Karls, A. Stukowski, W. Im, H. Heinz, A. Kohlmeyer, and E. B. Tadmor, J Phys Chem B, 128, 3282-3297 (2024).
.. _howto-MacKerell: .. _howto-MacKerell:
**(MacKerell)** MacKerell, Bashford, Bellott, Dunbrack, Evanseck, Field, **(MacKerell)** MacKerell, Bashford, Bellott, Dunbrack, Evanseck, Field, Fischer, Gao, Guo, Ha, et al (1998). J Phys Chem, 102, 3586 . https://doi.org/10.1021/jp973084f
Fischer, Gao, Guo, Ha, et al, J Phys Chem, 102, 3586 (1998).
.. _howto-Cornell: .. _howto-Cornell:
**(Cornell)** Cornell, Cieplak, Bayly, Gould, Merz, Ferguson, **(Cornell)** Cornell, Cieplak, Bayly, Gould, Merz, Ferguson, Spellmeyer, Fox, Caldwell, Kollman (1995). JACS 117, 5179-5197. https://doi.org/10.1021/ja00124a002
Spellmeyer, Fox, Caldwell, Kollman, JACS 117, 5179-5197 (1995).
.. _howto-Steinbach:
**(Steinbach)** Steinbach, Brooks (1994). J Comput Chem, 15, 667. https://doi.org/10.1002/jcc.540150702
.. _howto-Brooks:
**(Brooks)** Brooks, et al (2009). J Comput Chem, 30, 1545. https://onlinelibrary.wiley.com/doi/10.1002/jcc.21287
.. _howto-Sun: .. _howto-Sun:
**(Sun)** Sun, J. Phys. Chem. B, 102, 7338-7364 (1998). **(Sun)** Sun (1998). J. Phys. Chem. B, 102, 7338-7364. https://doi.org/10.1021/jp980939v
.. _howto-Mayo: .. _howto-Mayo:
**(Mayo)** Mayo, Olfason, Goddard III, J Phys Chem, 94, 8897-8909 **(Mayo)** Mayo, Olfason, Goddard III (1990). J Phys Chem, 94, 8897-8909. https://doi.org/10.1021/j100389a010
(1990).

View File

@ -15,7 +15,8 @@ orientation for rotational models. This produces a stress-free initial
state. Furthermore, bonds are allowed to break under large strains, state. Furthermore, bonds are allowed to break under large strains,
producing fracture. The examples/bpm directory has sample input scripts producing fracture. The examples/bpm directory has sample input scripts
for simulations of the fragmentation of an impacted plate and the for simulations of the fragmentation of an impacted plate and the
pouring of extended, elastic bodies. pouring of extended, elastic bodies. See :ref:`(Clemmer) <howto-Clemmer>`
for more general information on the approach and the LAMMPS implementation.
---------- ----------
@ -150,3 +151,9 @@ the following are currently compatible with BPM bond styles:
interactions, one will need to switch between different *special_bonds* interactions, one will need to switch between different *special_bonds*
settings in the input script. An example is found in settings in the input script. An example is found in
``examples/bpm/impact``. ``examples/bpm/impact``.
----------
.. _howto-Clemmer:
**(Clemmer)** Clemmer, Monti, Lechman, Soft Matter, 20, 1702 (2024).

View File

@ -13,6 +13,7 @@ This section documents the following functions:
- :cpp:func:`lammps_extract_setting` - :cpp:func:`lammps_extract_setting`
- :cpp:func:`lammps_extract_global_datatype` - :cpp:func:`lammps_extract_global_datatype`
- :cpp:func:`lammps_extract_global` - :cpp:func:`lammps_extract_global`
- :cpp:func:`lammps_map_atom`
-------------------- --------------------
@ -120,3 +121,8 @@ subdomains and processors.
.. doxygenfunction:: lammps_extract_global .. doxygenfunction:: lammps_extract_global
:project: progguide :project: progguide
-----------------------
.. doxygenfunction:: lammps_map_atom
:project: progguide

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@ -52,6 +52,7 @@ page gives those details.
* :ref:`DRUDE <PKG-DRUDE>` * :ref:`DRUDE <PKG-DRUDE>`
* :ref:`EFF <PKG-EFF>` * :ref:`EFF <PKG-EFF>`
* :ref:`ELECTRODE <PKG-ELECTRODE>` * :ref:`ELECTRODE <PKG-ELECTRODE>`
* :ref:`EXTRA-COMMAND <PKG-EXTRA-COMMAND>`
* :ref:`EXTRA-COMPUTE <PKG-EXTRA-COMPUTE>` * :ref:`EXTRA-COMPUTE <PKG-EXTRA-COMPUTE>`
* :ref:`EXTRA-DUMP <PKG-EXTRA-DUMP>` * :ref:`EXTRA-DUMP <PKG-EXTRA-DUMP>`
* :ref:`EXTRA-FIX <PKG-EXTRA-FIX>` * :ref:`EXTRA-FIX <PKG-EXTRA-FIX>`
@ -84,6 +85,7 @@ page gives those details.
* :ref:`ML-QUIP <PKG-ML-QUIP>` * :ref:`ML-QUIP <PKG-ML-QUIP>`
* :ref:`ML-RANN <PKG-ML-RANN>` * :ref:`ML-RANN <PKG-ML-RANN>`
* :ref:`ML-SNAP <PKG-ML-SNAP>` * :ref:`ML-SNAP <PKG-ML-SNAP>`
* :ref:`ML-UF3 <PKG-ML-UF3>`
* :ref:`MOFFF <PKG-MOFFF>` * :ref:`MOFFF <PKG-MOFFF>`
* :ref:`MOLECULE <PKG-MOLECULE>` * :ref:`MOLECULE <PKG-MOLECULE>`
* :ref:`MOLFILE <PKG-MOLFILE>` * :ref:`MOLFILE <PKG-MOLFILE>`
@ -403,6 +405,7 @@ and :ref:`ASPHERE <PKG-ASPHERE>` packages are installed.
* :doc:`bond_style oxdna2/\* <bond_oxdna>` * :doc:`bond_style oxdna2/\* <bond_oxdna>`
* :doc:`bond_style oxrna2/\* <bond_oxdna>` * :doc:`bond_style oxrna2/\* <bond_oxdna>`
* :doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>` * :doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>`
* examples/PACKAGES/cgdna
---------- ----------
@ -676,7 +679,12 @@ DPD-BASIC package
Pair styles for the basic dissipative particle dynamics (DPD) method Pair styles for the basic dissipative particle dynamics (DPD) method
and DPD thermostatting. and DPD thermostatting.
**Author:** Kurt Smith (U Pittsburgh), Martin Svoboda, Martin Lisal (ICPF and UJEP) Pair style :doc:`dpd/coul/slater/long <pair_dpd_coul_slater_long>` also
includes smeared charges for coulomb interactions and thus requires the
:ref:`KSPACE <PKG-KSPACE>` package to be installed to handle the long-range
Coulomb part of the interactions.
**Authors:** Kurt Smith (U Pittsburgh), Martin Svoboda, Martin Lisal (ICPF and UJEP), Eddy Barraud (IFPEN)
**Supporting info:** **Supporting info:**
@ -685,6 +693,7 @@ and DPD thermostatting.
* :doc:`pair_style dpd/tstat <pair_dpd>` * :doc:`pair_style dpd/tstat <pair_dpd>`
* :doc:`pair_style dpd/ext <pair_dpd_ext>` * :doc:`pair_style dpd/ext <pair_dpd_ext>`
* :doc:`pair_style dpd/ext/tstat <pair_dpd_ext>` * :doc:`pair_style dpd/ext/tstat <pair_dpd_ext>`
* :doc:`pair_style dpd/coul/slater/long <pair_dpd_coul_slater_long>`
* examples/PACKAGES/dpd-basic * examples/PACKAGES/dpd-basic
---------- ----------
@ -886,6 +895,22 @@ This package has :ref:`specific installation instructions <electrode>` on the
---------- ----------
.. _PKG-EXTRA-COMMAND:
EXTRA-COMMAND package
---------------------
**Contents:**
Additional command styles that are less commonly used.
**Supporting info:**
* src/EXTRA-COMMAND: filenames -> commands
* :doc:`general commands <Commands_all>`
----------
.. _PKG-EXTRA-COMPUTE: .. _PKG-EXTRA-COMPUTE:
EXTRA-COMPUTE package EXTRA-COMPUTE package
@ -1925,6 +1950,31 @@ computes which analyze attributes of the potential.
---------- ----------
.. _PKG-ML-UF3:
ML-UF3 package
--------------
**Contents:**
A pair style for the ultra-fast force field potentials (UF3). UF3 is a
methodology for deriving a highly accurate classical potential which is
fast to evaluate and is fitted to a large archives of quantum mechanical
(DFT) data. The use of b-spline basis set in UF3 enables the rapid
evaluation of 2-body and 3-body interactions.
**Authors:** Ajinkya C Hire (University of Florida),
Hendrik Krass (University of Constance),
Matthias Rupp (Luxembourg Institute of Science and Technology),
Richard Hennig (University of Florida)
**Supporting info:**
* src/ML-UF3: filenames -> commands
* :doc:`pair_style uf3 <pair_uf3>`
* examples/uf3
* https://github.com/uf3/uf3
.. _PKG-MOFFF: .. _PKG-MOFFF:
MOFFF package MOFFF package

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@ -158,6 +158,11 @@ whether an extra library is needed to build and use the package:
- :doc:`fix electrode/conp <fix_electrode>` - :doc:`fix electrode/conp <fix_electrode>`
- PACKAGES/electrode - PACKAGES/electrode
- no - no
* - :ref:`EXTRA-COMMAND <PKG-EXTRA-COMMAND>`
- additional command styles
- :doc:`general commands <Commands_all>`
- n/a
- no
* - :ref:`EXTRA-COMPUTE <PKG-EXTRA-COMPUTE>` * - :ref:`EXTRA-COMPUTE <PKG-EXTRA-COMPUTE>`
- additional compute styles - additional compute styles
- :doc:`compute <compute>` - :doc:`compute <compute>`
@ -318,6 +323,11 @@ whether an extra library is needed to build and use the package:
- :doc:`pair_style snap <pair_snap>` - :doc:`pair_style snap <pair_snap>`
- snap - snap
- no - no
* - :ref:`ML-UF3 <PKG-ML-UF3>`
- quantum-fitted ultra fast potentials
- :doc:`pair_style uf3 <pair_uf3>`
- PACKAGES/uf3
- no
* - :ref:`MOFFF <PKG-MOFFF>` * - :ref:`MOFFF <PKG-MOFFF>`
- styles for `MOF-FF <MOFplus_>`_ force field - styles for `MOF-FF <MOFplus_>`_ force field
- :doc:`pair_style buck6d/coul/gauss <pair_buck6d_coul_gauss>` - :doc:`pair_style buck6d/coul/gauss <pair_buck6d_coul_gauss>`

View File

@ -90,7 +90,7 @@ Miscellaneous tools
* :ref:`LAMMPS coding standards <coding_standard>` * :ref:`LAMMPS coding standards <coding_standard>`
* :ref:`emacs <emacs>` * :ref:`emacs <emacs>`
* :ref:`i-pi <ipi>` * :ref:`i-PI <ipi>`
* :ref:`kate <kate>` * :ref:`kate <kate>`
* :ref:`LAMMPS shell <lammps_shell>` * :ref:`LAMMPS shell <lammps_shell>`
* :ref:`LAMMPS GUI <lammps_gui>` * :ref:`LAMMPS GUI <lammps_gui>`
@ -376,21 +376,40 @@ See README file in the tools/fep directory.
.. _ipi: .. _ipi:
i-pi tool i-PI tool
------------------- -------------------
The tools/i-pi directory contains a version of the i-PI package, with .. versionchanged:: 27June2024
all the LAMMPS-unrelated files removed. It is provided so that it can
be used with the :doc:`fix ipi <fix_ipi>` command to perform The tools/i-pi directory used to contain a bundled version of the i-PI
path-integral molecular dynamics (PIMD). software package for use with LAMMPS. This version, however, was
removed in 06/2024.
The i-PI package was created and is maintained by Michele Ceriotti, The i-PI package was created and is maintained by Michele Ceriotti,
michele.ceriotti at gmail.com, to interface to a variety of molecular michele.ceriotti at gmail.com, to interface to a variety of molecular
dynamics codes. dynamics codes.
See the tools/i-pi/manual.pdf file for an overview of i-PI, and the i-PI is now available via PyPI using the pip package manager at:
:doc:`fix ipi <fix_ipi>` page for further details on running PIMD https://pypi.org/project/ipi/
calculations with LAMMPS.
Here are the commands to set up a virtual environment and install
i-PI into it with all its dependencies.
.. code-block:: sh
python -m venv ipienv
source ipienv/bin/activate
pip install --upgrade pip
pip install ipi
To install the development version from GitHub, please use:
.. code-block:: sh
pip install git+https://github.com/i-pi/i-pi.git
For further information, please consult the [i-PI home
page](https://ipi-code.org).
---------- ----------
@ -709,8 +728,8 @@ CMake is required.
The LAMMPS GUI has been successfully compiled and tested on: The LAMMPS GUI has been successfully compiled and tested on:
- Ubuntu Linux 20.04LTS x86_64 using GCC 9, Qt version 5.12 - Ubuntu Linux 20.04LTS x86_64 using GCC 9, Qt version 5.12
- Fedora Linux 38 x86\_64 using GCC 13 and Clang 16, Qt version 5.15LTS - Fedora Linux 40 x86\_64 using GCC 14 and Clang 17, Qt version 5.15LTS
- Fedora Linux 38 x86\_64 using GCC 13, Qt version 6.5LTS - Fedora Linux 40 x86\_64 using GCC 14, Qt version 6.5LTS
- Apple macOS 12 (Monterey) and macOS 13 (Ventura) with Xcode on arm64 and x86\_64, Qt version 5.15LTS - Apple macOS 12 (Monterey) and macOS 13 (Ventura) with Xcode on arm64 and x86\_64, Qt version 5.15LTS
- Windows 10 and 11 x86_64 with Visual Studio 2022 and Visual C++ 14.36, Qt version 5.15LTS - Windows 10 and 11 x86_64 with Visual Studio 2022 and Visual C++ 14.36, Qt version 5.15LTS
- Windows 10 and 11 x86_64 with MinGW / GCC 10.0 cross-compiler on Fedora 38, Qt version 5.15LTS - Windows 10 and 11 x86_64 with MinGW / GCC 10.0 cross-compiler on Fedora 38, Qt version 5.15LTS
@ -752,22 +771,23 @@ if necessary. When both, Qt5 and Qt6 are available, Qt6 will be preferred
unless ``-D LAMMPS_GUI_USE_QT5=yes`` is set. unless ``-D LAMMPS_GUI_USE_QT5=yes`` is set.
It should be possible to build the LAMMPS GUI as a standalone It should be possible to build the LAMMPS GUI as a standalone
compilation (e.g. when LAMMPS has been compiled with traditional make), compilation (e.g. when LAMMPS has been compiled with traditional make).
then the CMake configuration needs to be told where to find the LAMMPS Then the CMake configuration needs to be told where to find the LAMMPS
headers and the LAMMPS library, via ``-D headers and the LAMMPS library, via ``-D
LAMMPS_SOURCE_DIR=/path/to/lammps/src``. CMake will try to guess a LAMMPS_SOURCE_DIR=/path/to/lammps/src``. CMake will try to guess a
build folder with the LAMMPS library from that path, but it can also be build folder with the LAMMPS library from that path, but it can also be
set with ``-D LAMMPS_LIB_DIR=/path/to/lammps/lib``. set with ``-D LAMMPS_LIB_DIR=/path/to/lammps/lib``.
Rather than linking to the LAMMPS library during compilation, it is also Rather than linking to the LAMMPS library during compilation, it is also
possible to compile the GUI with a plugin loader library that will load possible to compile the GUI with a plugin loader that will load
the LAMMPS library dynamically at runtime during the start of the GUI the LAMMPS library dynamically at runtime during the start of the GUI
from a shared library; e.g. ``liblammps.so`` or ``liblammps.dylib`` or from a shared library; e.g. ``liblammps.so`` or ``liblammps.dylib`` or
``liblammps.dll`` (depending on the operating system). This has the ``liblammps.dll`` (depending on the operating system). This has the
advantage that the LAMMPS library can be updated LAMMPS without having advantage that the LAMMPS library can be built from updated or modified
to recompile the GUI. The ABI of the LAMMPS C-library interface is very LAMMPS source without having to recompile the GUI. The ABI of the
stable and generally backward compatible. This feature is enabled by LAMMPS C-library interface is very stable and generally backward
setting ``-D LAMMPS_GUI_USE_PLUGIN=on`` and then ``-D compatible. This feature is enabled by setting
``-D LAMMPS_GUI_USE_PLUGIN=on`` and then ``-D
LAMMPS_PLUGINLIB_DIR=/path/to/lammps/plugin/loader``. Typically, this LAMMPS_PLUGINLIB_DIR=/path/to/lammps/plugin/loader``. Typically, this
would be the ``examples/COUPLE/plugin`` folder of the LAMMPS would be the ``examples/COUPLE/plugin`` folder of the LAMMPS
distribution. distribution.
@ -779,8 +799,8 @@ macOS
""""" """""
When building on macOS, the build procedure will try to manufacture a When building on macOS, the build procedure will try to manufacture a
drag-n-drop installer, LAMMPS-macOS-multiarch.dmg, when using the 'dmg' drag-n-drop installer, ``LAMMPS-macOS-multiarch.dmg``, when using the
target (i.e. ``cmake --build <build dir> --target dmg`` or ``make dmg``. 'dmg' target (i.e. ``cmake --build <build dir> --target dmg`` or ``make dmg``.
To build multi-arch executables that will run on both, arm64 and x86_64 To build multi-arch executables that will run on both, arm64 and x86_64
architectures natively, it is necessary to set the CMake variable ``-D architectures natively, it is necessary to set the CMake variable ``-D
@ -819,12 +839,12 @@ and LAMMPS GUI can be launched from anywhere from the command line.
The standard CMake build procedure can be applied and the The standard CMake build procedure can be applied and the
``mingw-cross.cmake`` preset used. By using ``mingw64-cmake`` the CMake ``mingw-cross.cmake`` preset used. By using ``mingw64-cmake`` the CMake
command will automatically include a suitable CMake toolset file (the command will automatically include a suitable CMake toolchain file (the
regular cmake command can be used after that). After building the regular cmake command can be used after that to modify the configuration
libraries and executables, you can build the target 'zip' settings, if needed). After building the libraries and executables,
(i.e. ``cmake --build <build dir> --target zip`` or ``make zip`` you can build the target 'zip' (i.e. ``cmake --build <build dir> --target zip``
to stage all installed files into a LAMMPS_GUI folder and then or ``make zip`` to stage all installed files into a LAMMPS_GUI folder
run a script to copy all required dependencies, some other files, and then run a script to copy all required dependencies, some other files,
and create a zip file from it. and create a zip file from it.
Linux Linux

View File

@ -71,11 +71,11 @@ all atoms, e.g. in a data or restart file.
atom IDs are required, due to how neighbor lists are built. atom IDs are required, due to how neighbor lists are built.
The *map* keyword determines how atoms with specific IDs are found The *map* keyword determines how atoms with specific IDs are found
when required. An example are the bond (angle, etc) methods which when required. For example, the bond (angle, etc) methods need to
need to find the local index of an atom with a specific global ID find the local index of an atom with a specific global ID which is a
which is a bond (angle, etc) partner. LAMMPS performs this operation bond (angle, etc) partner. LAMMPS performs this operation efficiently
efficiently by creating a "map", which is either an *array* or *hash* by creating a "map", which is either an *array* or *hash* table, as
table, as described below. described below.
When the *map* keyword is not specified in your input script, LAMMPS When the *map* keyword is not specified in your input script, LAMMPS
only creates a map for :doc:`atom_styles <atom_style>` for molecular only creates a map for :doc:`atom_styles <atom_style>` for molecular
@ -83,34 +83,39 @@ systems which have permanent bonds (angles, etc). No map is created
for atomic systems, since it is normally not needed. However some for atomic systems, since it is normally not needed. However some
LAMMPS commands require a map, even for atomic systems, and will LAMMPS commands require a map, even for atomic systems, and will
generate an error if one does not exist. The *map* keyword thus generate an error if one does not exist. The *map* keyword thus
allows you to force the creation of a map. The *yes* value will allows you to force the creation of a map.
create either an *array* or *hash* style map, as explained in the next
paragraph. The *array* and *hash* values create an array-style or
hash-style map respectively.
For an *array*\ -style map, each processor stores a lookup table of Specifying a value of *yes* will create either an array-style or
length N, where N is the largest atom ID in the system. This is a hash-style map, depending on the size of the system. If no atom ID is
fast, simple method for many simulations, but requires too much memory larger than 1 million, then an array-style map is used, otherwise a
for large simulations. For a *hash*\ -style map, a hash table is hash-style map is used. Specifying a value of *array* or *hash*
created on each processor, which finds an atom ID in constant time creates an array-style or hash-style map respectively, regardless of
(independent of the global number of atom IDs). It can be slightly the size of the system.
slower than the *array* map, but its memory cost is proportional to
the number of atoms owned by a processor, i.e. N/P when N is the total
number of atoms in the system and P is the number of processors.
The *first* keyword allows a :doc:`group <group>` to be specified whose For an array-style map, each processor stores a lookup table of length
atoms will be maintained as the first atoms in each processor's list N, where N is the largest atom ID in the system. This is a fast,
of owned atoms. This in only useful when the specified group is a simple method for many simulations, but requires too much memory for
small fraction of all the atoms, and there are other operations LAMMPS large simulations. For a hash-style map, a hash table is created on
is performing that will be sped-up significantly by being able to loop each processor, which finds an atom ID in constant time (independent
over the smaller set of atoms. Otherwise the reordering required by of the global number of atom IDs). It can be slightly slower than the
this option will be a net slow-down. The :doc:`neigh_modify include <neigh_modify>` and :doc:`comm_modify group <comm_modify>` *array* map, but its memory cost is proportional to the number of
commands are two examples of commands that require this setting to atoms owned by a processor, i.e. N/P when N is the total number of
work efficiently. Several :doc:`fixes <fix>`, most notably time atoms in the system and P is the number of processors.
integration fixes like :doc:`fix nve <fix_nve>`, also take advantage of
this setting if the group they operate on is the group specified by The *first* keyword allows a :doc:`group <group>` to be specified
this command. Note that specifying "all" as the group-ID effectively whose atoms will be maintained as the first atoms in each processor's
turns off the *first* option. list of owned atoms. This in only useful when the specified group is
a small fraction of all the atoms, and there are other operations
LAMMPS is performing that will be sped-up significantly by being able
to loop over the smaller set of atoms. Otherwise the reordering
required by this option will be a net slow-down. The
:doc:`neigh_modify include <neigh_modify>` and :doc:`comm_modify group
<comm_modify>` commands are two examples of commands that require this
setting to work efficiently. Several :doc:`fixes <fix>`, most notably
time integration fixes like :doc:`fix nve <fix_nve>`, also take
advantage of this setting if the group they operate on is the group
specified by this command. Note that specifying "all" as the group-ID
effectively turns off the *first* option.
It is OK to use the *first* keyword with a group that has not yet been It is OK to use the *first* keyword with a group that has not yet been
defined, e.g. to use the atom_modify first command at the beginning of defined, e.g. to use the atom_modify first command at the beginning of
@ -148,15 +153,16 @@ cache locality will be undermined.
.. note:: .. note::
Running a simulation with sorting on versus off should not Running a simulation with sorting on versus off should not change
change the simulation results in a statistical sense. However, a the simulation results in a statistical sense. However, a
different ordering will induce round-off differences, which will lead different ordering will induce round-off differences, which will
to diverging trajectories over time when comparing two simulations. lead to diverging trajectories over time when comparing two
Various commands, particularly those which use random numbers simulations. Various commands, particularly those which use random
(e.g. :doc:`velocity create <velocity>`, and :doc:`fix langevin <fix_langevin>`), may generate (statistically identical) numbers (e.g. :doc:`velocity create <velocity>`, and :doc:`fix
results which depend on the order in which atoms are processed. The langevin <fix_langevin>`), may generate (statistically identical)
order of atoms in a :doc:`dump <dump>` file will also typically change results which depend on the order in which atoms are processed.
if sorting is enabled. The order of atoms in a :doc:`dump <dump>` file will also typically
change if sorting is enabled.
.. note:: .. note::
@ -183,12 +189,13 @@ Default
By default, *id* is yes. By default, atomic systems (no bond topology By default, *id* is yes. By default, atomic systems (no bond topology
info) do not use a map. For molecular systems (with bond topology info) do not use a map. For molecular systems (with bond topology
info), a map is used. The default map style is array if no atom ID is info), the default is to use a map of either *array* or *hash* style
larger than 1 million, otherwise the default is hash. By default, a depending on the size of the sustem, as explained above for the *map
"first" group is not defined. By default, sorting is enabled with a yes* keyword/value option. By default, a *first* group is not
frequency of 1000 and a binsize of 0.0, which means the neighbor defined. By default, sorting is enabled with a frequency of 1000 and
cutoff will be used to set the bin size. If no neighbor cutoff is a binsize of 0.0, which means the neighbor cutoff will be used to set
defined, sorting will be turned off. the bin size. If no neighbor cutoff is defined, sorting will be turned
off.
---------- ----------

View File

@ -1,8 +1,11 @@
.. index:: bond_style hybrid .. index:: bond_style hybrid
.. index:: bond_style hybrid/kk
bond_style hybrid command bond_style hybrid command
========================= =========================
Accelerator Variants: *hybrid/kk*
Syntax Syntax
"""""" """"""
@ -15,7 +18,7 @@ Syntax
Examples Examples
"""""""" """"""""
.. code-block: LAMMPS .. code-block:: LAMMPS
bond_style hybrid harmonic fene bond_style hybrid harmonic fene
bond_coeff 1 harmonic 80.0 1.2 bond_coeff 1 harmonic 80.0 1.2
@ -60,6 +63,10 @@ bond types.
---------- ----------
.. include:: accel_styles.rst
----------
Restrictions Restrictions
"""""""""""" """"""""""""

View File

@ -27,6 +27,7 @@ Examples
.. code-block:: LAMMPS .. code-block:: LAMMPS
# LJ units
bond_style oxdna/fene bond_style oxdna/fene
bond_coeff * 2.0 0.25 0.7525 bond_coeff * 2.0 0.25 0.7525
@ -36,6 +37,32 @@ Examples
bond_style oxrna2/fene bond_style oxrna2/fene
bond_coeff * 2.0 0.25 0.76107 bond_coeff * 2.0 0.25 0.76107
bond_style oxdna/fene
bond_coeff * oxdna_lj.cgdna
# Real units
bond_style oxdna/fene
bond_coeff * 11.92337812042065 2.1295 6.409795
bond_style oxdna2/fene
bond_coeff * 11.92337812042065 2.1295 6.4430152
bond_style oxrna2/fene
bond_coeff * 11.92337812042065 2.1295 6.482800913
bond_style oxrna2/fene
bond_coeff * oxrna2_real.cgdna
.. note::
The coefficients in the above examples have to be kept fixed and
cannot be changed without reparameterizing the entire model. They are
provided in forms compatible with both *units lj* and *units real*
(see documentation of :doc:`units <units>`). These can also be read
from a potential file with correct unit style by specifying the name
of the file. Several potential files for each unit style are included
in the ``potentials`` directory of the LAMMPS distribution.
Description Description
""""""""""" """""""""""
@ -46,15 +73,14 @@ The *oxdna/fene*, *oxdna2/fene*, and *oxrna2/fene* bond styles use the potential
E = - \frac{\epsilon}{2} \ln \left[ 1 - \left(\frac{r-r_0}{\Delta}\right)^2\right] E = - \frac{\epsilon}{2} \ln \left[ 1 - \left(\frac{r-r_0}{\Delta}\right)^2\right]
to define a modified finite extensible nonlinear elastic (FENE) to define a modified finite extensible nonlinear elastic (FENE)
potential :ref:`(Ouldridge) <Ouldridge0>` to model the connectivity of the potential :ref:`(Ouldridge) <Ouldridge0>` to model the connectivity of
phosphate backbone in the oxDNA/oxRNA force field for coarse-grained the phosphate backbone in the oxDNA/oxRNA force field for coarse-grained
modelling of DNA/RNA. modelling of DNA/RNA.
The following coefficients must be defined for the bond type via the The following coefficients must be defined for the bond type via the
:doc:`bond_coeff <bond_coeff>` command as given in the above example, or :doc:`bond_coeff <bond_coeff>` command as given in the above example, or
in the data file or restart files read by the in the data file or restart files read by the :doc:`read_data
:doc:`read_data <read_data>` or :doc:`read_restart <read_restart>` <read_data>` or :doc:`read_restart <read_restart>` commands:
commands:
* :math:`\epsilon` (energy) * :math:`\epsilon` (energy)
* :math:`\Delta` (distance) * :math:`\Delta` (distance)
@ -62,41 +88,40 @@ commands:
.. note:: .. note::
The oxDNA bond style has to be used together with the The oxDNA bond style has to be used together with the corresponding
corresponding oxDNA pair styles for excluded volume interaction oxDNA pair styles for excluded volume interaction *oxdna/excv* ,
*oxdna/excv* , stacking *oxdna/stk* , cross-stacking *oxdna/xstk* and stacking *oxdna/stk* , cross-stacking *oxdna/xstk* and coaxial
coaxial stacking interaction *oxdna/coaxstk* as well as stacking interaction *oxdna/coaxstk* as well as hydrogen-bonding
hydrogen-bonding interaction *oxdna/hbond* (see also documentation of interaction *oxdna/hbond* (see also documentation of :doc:`pair_style
:doc:`pair_style oxdna/excv <pair_oxdna>`). For the oxDNA2 oxdna/excv <pair_oxdna>`). For the oxDNA2 :ref:`(Snodin) <Snodin0>`
:ref:`(Snodin) <Snodin0>` bond style the analogous pair styles bond style the analogous pair styles *oxdna2/excv* , *oxdna2/stk* ,
*oxdna2/excv* , *oxdna2/stk* , *oxdna2/xstk* , *oxdna2/coaxstk* , *oxdna2/xstk* , *oxdna2/coaxstk* , *oxdna2/hbond* and an additional
*oxdna2/hbond* and an additional Debye-Hueckel pair style Debye-Hueckel pair style *oxdna2/dh* have to be defined. The same
*oxdna2/dh* have to be defined. The same applies to the oxRNA2 applies to the oxRNA2 :ref:`(Sulc1) <Sulc01>` styles.
:ref:`(Sulc1) <Sulc01>` styles.
The coefficients in the above example have to be kept fixed and cannot
be changed without reparameterizing the entire model.
.. note:: .. note::
This bond style has to be used with the *atom_style hybrid bond ellipsoid oxdna* This bond style has to be used with the *atom_style hybrid bond
(see documentation of :doc:`atom_style <atom_style>`). The *atom_style oxdna* ellipsoid oxdna* (see documentation of :doc:`atom_style
stores the 3'-to-5' polarity of the nucleotide strand, which is set through <atom_style>`). The *atom_style oxdna* stores the 3'-to-5' polarity
the bond topology in the data file. The first (second) atom in a bond definition of the nucleotide strand, which is set through the bond topology in
is understood to point towards the 3'-end (5'-end) of the strand. the data file. The first (second) atom in a bond definition is
understood to point towards the 3'-end (5'-end) of the strand.
.. warning:: .. warning::
If data files are produced with :doc:`write_data <write_data>`, then the If data files are produced with :doc:`write_data <write_data>`, then
:doc:`newton <newton>` command should be set to *newton on* or *newton off on*. the :doc:`newton <newton>` command should be set to *newton on* or
Otherwise the data files will not have the same 3'-to-5' polarity as the *newton off on*. Otherwise the data files will not have the same
initial data file. This limitation does not apply to binary restart files 3'-to-5' polarity as the initial data file. This limitation does not
produced with :doc:`write_restart <write_restart>`. apply to binary restart files produced with :doc:`write_restart
<write_restart>`.
Example input and data files for DNA and RNA duplexes can be found in Example input and data files for DNA and RNA duplexes can be found in
examples/PACKAGES/cgdna/examples/oxDNA/ , /oxDNA2/ and /oxRNA2/. A simple python ``examples/PACKAGES/cgdna/examples/oxDNA/`, `.../oxDNA2/`` and
setup tool which creates single straight or helical DNA strands, DNA/RNA ``.../oxRNA2/``. A simple python setup tool which creates single
duplexes or arrays of DNA/RNA duplexes can be found in straight or helical DNA strands, DNA/RNA duplexes or arrays of DNA/RNA
examples/PACKAGES/cgdna/util/. duplexes can be found in ``examples/PACKAGES/cgdna/util/``.
Please cite :ref:`(Henrich) <Henrich0>` in any publication that uses Please cite :ref:`(Henrich) <Henrich0>` in any publication that uses
this implementation. An updated documentation that contains general information this implementation. An updated documentation that contains general information
@ -113,6 +138,39 @@ and for sequence-specific hydrogen-bonding and stacking interactions
---------- ----------
Potential file reading
""""""""""""""""""""""
For each style oxdna, oxdna2 and oxrna2, the first parameter argument
can be a filename, and if it is, no further arguments should be
supplied. Therefore the following command:
.. code-block:: LAMMPS
bond_style oxdna/fene
bond_coeff * oxdna_lj.cgdna
will be interpreted as a request to read the (FENE) potential
:ref:`(Ouldridge) <Ouldridge0>` parameters from the file with the given
name. The file can define multiple potential parameters for both bonded
and pair interactions, but for the above bonded interactions there must
exist in the file a line of the form:
.. code-block:: LAMMPS
* fene epsilon delta r0
There are sample potential files for each unit style in the
``potentials`` directory of the LAMMPS distribution. The potential file
unit system must align with the units defined via the :doc:`units
<units>` command. For conversion between different *LJ* and *real* unit
systems for oxDNA, the python tool *lj2real.py* located in the
``examples/PACKAGES/cgdna/util/`` directory can be used. This tool
assumes similar file structure to the examples found in
``examples/PACKAGES/cgdna/examples/``.
----------
Restrictions Restrictions
"""""""""""" """"""""""""

View File

@ -272,6 +272,10 @@ The individual style names on the :doc:`Commands compute <Commands_compute>` pag
* :doc:`pe/mol/tally <compute_tally>` - potential energy between two groups of atoms separated into intermolecular and intramolecular components via the tally callback mechanism * :doc:`pe/mol/tally <compute_tally>` - potential energy between two groups of atoms separated into intermolecular and intramolecular components via the tally callback mechanism
* :doc:`pe/tally <compute_tally>` - potential energy between two groups of atoms via the tally callback mechanism * :doc:`pe/tally <compute_tally>` - potential energy between two groups of atoms via the tally callback mechanism
* :doc:`plasticity/atom <compute_plasticity_atom>` - Peridynamic plasticity for each atom * :doc:`plasticity/atom <compute_plasticity_atom>` - Peridynamic plasticity for each atom
* :doc:`pod/atom <compute_pod_atom>` - POD descriptors for each atom
* :doc:`podd/atom <compute_pod_atom>` - derivative of POD descriptors for each atom
* :doc:`pod/local <compute_pod_atom>` - local POD descriptors and their derivatives
* :doc:`pod/global <compute_pod_atom>` - global POD descriptors and their derivatives
* :doc:`pressure <compute_pressure>` - total pressure and pressure tensor * :doc:`pressure <compute_pressure>` - total pressure and pressure tensor
* :doc:`pressure/alchemy <compute_pressure_alchemy>` - mixed system total pressure and pressure tensor for :doc:`fix alchemy <fix_alchemy>` runs * :doc:`pressure/alchemy <compute_pressure_alchemy>` - mixed system total pressure and pressure tensor for :doc:`fix alchemy <fix_alchemy>` runs
* :doc:`pressure/uef <compute_pressure_uef>` - pressure tensor in the reference frame of an applied flow field * :doc:`pressure/uef <compute_pressure_uef>` - pressure tensor in the reference frame of an applied flow field

View File

@ -12,7 +12,7 @@ Syntax
* ID, group-ID are documented in :doc:`compute <compute>` command * ID, group-ID are documented in :doc:`compute <compute>` command
* count/type = style name of this compute command * count/type = style name of this compute command
* mode = {atom} or {bond} or {angle} or {dihedral} or {improper} * mode = *atom* or *bond* or *angle* or *dihedral* or *improper*
Examples Examples
"""""""" """"""""
@ -69,29 +69,42 @@ for each type:
---------- ----------
If the {mode} setting is {atom} then the count of atoms for each atom If the *mode* setting is *atom* then the count of atoms for each atom
type is tallied. Only atoms in the specified group are counted. type is tallied. Only atoms in the specified group are counted.
If the {mode} setting is {bond} then the count of bonds for each bond The atom count for each type can be normalized by the total number of
atoms like so:
.. code-block:: LAMMPS
compute typevec all count/type atom # number of atoms of each type
variable normtypes vector c_typevec/atoms # divide by total number of atoms
variable ntypes equal extract_setting(ntypes) # number of atom types
thermo_style custom step v_normtypes[*${ntypes}] # vector variable needs upper limit
Similarly, bond counts can be normalized by the total number of bonds.
The same goes for angles, dihedrals, and impropers (see below).
If the *mode* setting is *bond* then the count of bonds for each bond
type is tallied. Only bonds with both atoms in the specified group type is tallied. Only bonds with both atoms in the specified group
are counted. are counted.
For {mode} = {bond}, broken bonds with a bond type of zero are also For *mode* = *bond*, broken bonds with a bond type of zero are also
counted. The :doc:`bond_style quartic <bond_quartic>` and :doc:`BPM counted. The :doc:`bond_style quartic <bond_quartic>` and :doc:`BPM
bond styles <Howto_bpm>` break bonds by doing this. See the :doc:` bond styles <Howto_bpm>` break bonds by doing this. See the
Howto broken bonds <Howto_broken_bonds>` doc page for more details. :doc:`Howto broken bonds <Howto_broken_bonds>` doc page for more details.
Note that the group setting is ignored for broken bonds; all broken Note that the group setting is ignored for broken bonds; all broken
bonds in the system are counted. bonds in the system are counted.
If the {mode} setting is {angle} then the count of angles for each If the *mode* setting is *angle* then the count of angles for each
angle type is tallied. Only angles with all 3 atoms in the specified angle type is tallied. Only angles with all 3 atoms in the specified
group are counted. group are counted.
If the {mode} setting is {dihedral} then the count of dihedrals for If the *mode* setting is *dihedral* then the count of dihedrals for
each dihedral type is tallied. Only dihedrals with all 4 atoms in the each dihedral type is tallied. Only dihedrals with all 4 atoms in the
specified group are counted. specified group are counted.
If the {mode} setting is {improper} then the count of impropers for If the *mode* setting is *improper* then the count of impropers for
each improper type is tallied. Only impropers with all 4 atoms in the each improper type is tallied. Only impropers with all 4 atoms in the
specified group are counted. specified group are counted.
@ -101,18 +114,19 @@ Output info
""""""""""" """""""""""
This compute calculates a global vector of counts. If the mode is This compute calculates a global vector of counts. If the mode is
{atom} or {bond} or {angle} or {dihedral} or {improper}, then the *atom* or *bond* or *angle* or *dihedral* or *improper*, then the
vector length is the number of atom types or bond types or angle types vector length is the number of atom types or bond types or angle types
or dihedral types or improper types, respectively. or dihedral types or improper types, respectively.
If the mode is {bond} this compute also calculates a global scalar If the mode is *bond* this compute also calculates a global scalar
which is the number of broken bonds with type = 0, as explained above. which is the number of broken bonds with type = 0, as explained above.
These values can be used by any command that uses global scalar or These values can be used by any command that uses global scalar or
vector values from a compute as input. See the :doc:`Howto output vector values from a compute as input. See the :doc:`Howto output
<Howto_output>` page for an overview of LAMMPS output options. <Howto_output>` page for an overview of LAMMPS output options.
The scalar and vector values calculated by this compute are "extensive". The scalar and vector values calculated by this compute are both
"intensive".
Restrictions Restrictions
"""""""""""" """"""""""""

View File

@ -0,0 +1,145 @@
.. index:: compute pod/atom
.. index:: compute podd/atom
.. index:: compute pod/local
.. index:: compute pod/global
compute pod/atom command
========================
compute podd/atom command
=========================
compute pod/local command
=========================
compute pod/global command
==========================
Syntax
""""""
.. code-block:: LAMMPS
compute ID group-ID pod/atom param.pod coefficients.pod
compute ID group-ID podd/atom param.pod coefficients.pod
compute ID group-ID pod/local param.pod coefficients.pod
compute ID group-ID pod/global param.pod coefficients.pod
* ID, group-ID are documented in :doc:`compute <compute>` command
* pod/atom = style name of this compute command
* param.pod = the parameter file specifies parameters of the POD descriptors
* coefficients.pod = the coefficient file specifies coefficients of the POD potential
Examples
""""""""
.. code-block:: LAMMPS
compute d all pod/atom Ta_param.pod
compute dd all podd/atom Ta_param.pod
compute ldd all pod/local Ta_param.pod
compute gdd all podd/global Ta_param.pod
compute d all pod/atom Ta_param.pod Ta_coefficients.pod
compute dd all podd/atom Ta_param.pod Ta_coefficients.pod
compute ldd all pod/local Ta_param.pod Ta_coefficients.pod
compute gdd all podd/global Ta_param.pod Ta_coefficients.pod
Description
"""""""""""
.. versionadded:: 27June2024
Define a computation that calculates a set of quantities related to the
POD descriptors of the atoms in a group. These computes are used
primarily for calculating the dependence of energy and force components
on the linear coefficients in the :doc:`pod pair_style <pair_pod>`,
which is useful when training a POD potential to match target data. POD
descriptors of an atom are characterized by the radial and angular
distribution of neighbor atoms. The detailed mathematical definition is
given in the papers by :ref:`(Nguyen and Rohskopf) <Nguyen20222c>`,
:ref:`(Nguyen2023) <Nguyen20232c>`, :ref:`(Nguyen2024) <Nguyen20242c>`,
and :ref:`(Nguyen and Sema) <Nguyen20243c>`.
Compute *pod/atom* calculates the per-atom POD descriptors.
Compute *podd/atom* calculates derivatives of the per-atom POD
descriptors with respect to atom positions.
Compute *pod/local* calculates the per-atom POD descriptors and their
derivatives with respect to atom positions.
Compute *pod/global* calculates the global POD descriptors and their
derivatives with respect to atom positions.
Examples how to use Compute POD commands are found in the directory
``examples/PACKAGES/pod``.
.. warning::
All of these compute styles produce *very* large per-atom output
arrays that scale with the total number of atoms in the system.
This will result in *very* large memory consumption for systems
with a large number of atoms.
----------
Output info
"""""""""""
Compute *pod/atom* produces an 2D array of size :math:`N \times M`,
where :math:`N` is the number of atoms and :math:`M` is the number of
descriptors. Each column corresponds to a particular POD descriptor.
Compute *podd/atom* produces an 2D array of size :math:`N \times (M * 3
N)`. Each column corresponds to a particular derivative of a POD
descriptor.
Compute *pod/local* produces an 2D array of size :math:`(1 + 3N) \times
(M * N)`. The first row contains the per-atom descriptors, and the last
3N rows contain the derivatives of the per-atom descriptors with respect
to atom positions.
Compute *pod/global* produces an 2D array of size :math:`(1 + 3N) \times
(M)`. The first row contains the global descriptors, and the last 3N
rows contain the derivatives of the global descriptors with respect to
atom positions.
Restrictions
""""""""""""
These computes are part of the ML-POD package. They are only enabled
if LAMMPS was built with that package. See the :doc:`Build package
<Build_package>` page for more info.
Related commands
""""""""""""""""
:doc:`fitpod <fitpod_command>`,
:doc:`pair_style pod <pair_pod>`
Default
"""""""
none
----------
.. _Nguyen20222c:
**(Nguyen and Rohskopf)** Nguyen and Rohskopf, Journal of Computational Physics, 480, 112030, (2023).
.. _Nguyen20232c:
**(Nguyen2023)** Nguyen, Physical Review B, 107(14), 144103, (2023).
.. _Nguyen20242c:
**(Nguyen2024)** Nguyen, Journal of Computational Physics, 113102, (2024).
.. _Nguyen20243c:
**(Nguyen and Sema)** Nguyen and Sema, https://arxiv.org/abs/2405.00306, (2024).

View File

@ -13,8 +13,8 @@ Syntax
* ID, group-ID are documented in :doc:`compute <compute>` command * ID, group-ID are documented in :doc:`compute <compute>` command
* rdf = style name of this compute command * rdf = style name of this compute command
* Nbin = number of RDF bins * Nbin = number of RDF bins
* itypeN = central atom type for Nth RDF histogram (see asterisk form below) * itypeN = central atom type for Nth RDF histogram (integer, type label, or asterisk form)
* jtypeN = distribution atom type for Nth RDF histogram (see asterisk form below) * jtypeN = distribution atom type for Nth RDF histogram (integer, type label, or asterisk form)
* zero or more keyword/value pairs may be appended * zero or more keyword/value pairs may be appended
* keyword = *cutoff* * keyword = *cutoff*
@ -96,14 +96,16 @@ is computed for :math:`g(r)` between all atom types. If one or more pairs are
listed, then a separate histogram is generated for each listed, then a separate histogram is generated for each
*itype*,\ *jtype* pair. *itype*,\ *jtype* pair.
The *itypeN* and *jtypeN* settings can be specified in one of two The *itypeN* and *jtypeN* settings can be specified in one of three
ways. An explicit numeric value can be used, as in the fourth example ways. One or both of the types in the I,J pair can be a
above. Or a wild-card asterisk can be used to specify a range of atom :doc:`type label <Howto_type_labels>`. Or an explicit numeric value can be
types. This takes the form "\*" or "\*n" or "m\*" or "m\*n". If used, as in the fourth example above. Or a wild-card asterisk can be used
:math:`N` is the number of atom types, then an asterisk with no numeric values to specify a range of atom types. This takes the form "\*" or "\*n" or
means all types from 1 to :math:`N`. A leading asterisk means all types from 1 "m\*" or "m\*n". If :math:`N` is the number of atom types, then an asterisk
to n (inclusive). A trailing asterisk means all types from m to :math:`N` with no numeric values means all types from 1 to :math:`N`. A leading
(inclusive). A middle asterisk means all types from m to n (inclusive). asterisk means all types from 1 to n (inclusive). A trailing asterisk
means all types from m to :math:`N` (inclusive). A middle asterisk means
all types from m to n (inclusive).
If both *itypeN* and *jtypeN* are single values, as in the fourth example If both *itypeN* and *jtypeN* are single values, as in the fourth example
above, this means that a :math:`g(r)` is computed where atoms of type *itypeN* above, this means that a :math:`g(r)` is computed where atoms of type *itypeN*

View File

@ -126,7 +126,7 @@ These styles are part of the EXTRA-COMPUTE package. They are only
enabled if LAMMPS is built with that package. See the :doc:`Build enabled if LAMMPS is built with that package. See the :doc:`Build
package <Build_package>` doc page on for more info. package <Build_package>` doc page on for more info.
The method is only implemented for 3d orthogonal simulation boxes whose The method is implemented for orthogonal simulation boxes whose
size does not change in time, and axis-aligned planes. size does not change in time, and axis-aligned planes.
The method only works with two-body pair interactions, because it The method only works with two-body pair interactions, because it

View File

@ -10,7 +10,7 @@ Syntax
create_atoms type style args keyword values ... create_atoms type style args keyword values ...
* type = atom type (1-Ntypes) of atoms to create (offset for molecule creation) * type = atom type (1-Ntypes or type label) of atoms to create (offset for molecule creation)
* style = *box* or *region* or *single* or *mesh* or *random* * style = *box* or *region* or *single* or *mesh* or *random*
.. parsed-literal:: .. parsed-literal::
@ -37,7 +37,7 @@ Syntax
seed = random # seed (positive integer) seed = random # seed (positive integer)
*basis* values = M itype *basis* values = M itype
M = which basis atom M = which basis atom
itype = atom type (1-N) to assign to this basis atom itype = atom type (1-Ntypes or type label) to assign to this basis atom
*ratio* values = frac seed *ratio* values = frac seed
frac = fraction of lattice sites (0 to 1) to populate randomly frac = fraction of lattice sites (0 to 1) to populate randomly
seed = random # seed (positive integer) seed = random # seed (positive integer)
@ -74,6 +74,13 @@ Examples
.. code-block:: LAMMPS .. code-block:: LAMMPS
create_atoms 1 box create_atoms 1 box
labelmap atom 1 Pt
create_atoms Pt box
labelmap atom 1 C 2 Si
create_atoms C region regsphere basis Si C
create_atoms 3 region regsphere basis 2 3 create_atoms 3 region regsphere basis 2 3
create_atoms 3 region regsphere basis 2 3 ratio 0.5 74637 create_atoms 3 region regsphere basis 2 3 ratio 0.5 74637
create_atoms 3 single 0 0 5 create_atoms 3 single 0 0 5
@ -468,12 +475,13 @@ to.
The *overlap* keyword only applies to the *random* style. It prevents The *overlap* keyword only applies to the *random* style. It prevents
newly created particles from being created closer than the specified newly created particles from being created closer than the specified
*Doverlap* distance from any other particle. When the particles being *Doverlap* distance from any other particle. If particles have finite
created are molecules, the radius of the molecule (from its geometric size (see :doc:`atom_style sphere <atom_style>` for example) *Doverlap*
center) is added to *Doverlap*. If particles have finite size (see should be specified large enough to include the particle size in the
:doc:`atom_style sphere <atom_style>` for example) *Doverlap* should non-overlapping criterion. If molecules are being randomly inserted, then
be specified large enough to include the particle size in the an insertion is only accepted if each particle in the molecule meets the
non-overlapping criterion. overlap criterion with respect to other particles (not including particles
in the molecule itself).
.. note:: .. note::

View File

@ -43,6 +43,9 @@ Examples
delete_bonds all bond 0*3 special delete_bonds all bond 0*3 special
delete_bonds all stats delete_bonds all stats
labelmap atom 4 hc
delete_bonds all atom hc special
Description Description
""""""""""" """""""""""
@ -59,19 +62,20 @@ For all styles, by default, an interaction is only turned off (or on)
if all the atoms involved are in the specified group. See the *any* if all the atoms involved are in the specified group. See the *any*
keyword to change the behavior. keyword to change the behavior.
Several of the styles (\ *atom*, *bond*, *angle*, *dihedral*, Several of the styles (\ *atom*, *bond*, *angle*, *dihedral*, *improper*\ )
*improper*\ ) take a *type* as an argument. The specified *type* should take a *type* as an argument. The specified *type* can be a
be an integer from 0 to :math:`N`, where :math:`N` is the number of relevant :doc:`type label <Howto_type_labels>`. Otherwise, the type should be an
integer from 0 to :math:`N`, where :math:`N` is the number of relevant
types (atom types, bond types, etc.). A value of 0 is only relevant for types (atom types, bond types, etc.). A value of 0 is only relevant for
style *bond*\ ; see details below. In all cases, a wildcard asterisk style *bond*\ ; see details below. For numeric types, a wildcard asterisk
can be used in place of or in conjunction with the *type* argument to can be used in place of or in conjunction with the *type* argument to
specify a range of types. This takes the form "\*" or "\*n" or "m\*" or specify a range of types. This takes the form "\*" or "\*n" or "m\*" or
"m\*n". If :math:`N` is the number of types, then an asterisk with no numeric "m\*n". If :math:`N` is the number of types, then an asterisk with no
values means all types from 0 to :math:`N`. A leading asterisk means all numeric values means all types from 0 to :math:`N`. A leading asterisk
types from 0 to n (inclusive). A trailing asterisk means all types means all types from 0 to n (inclusive). A trailing asterisk means all
from m to N (inclusive). A middle asterisk means all types from m to types from m to N (inclusive). A middle asterisk means all types from m to
n (inclusive). Note that it is fine to include a type of 0 for n (inclusive). Note that it is fine to include a type of 0 for non-bond
non-bond styles; it will simply be ignored. styles; it will simply be ignored.
For style *multi* all bond, angle, dihedral, and improper interactions For style *multi* all bond, angle, dihedral, and improper interactions
of any type, involving atoms in the group, are turned off. of any type, involving atoms in the group, are turned off.

View File

@ -114,6 +114,7 @@ Syntax
proc = ID of processor that owns atom proc = ID of processor that owns atom
procp1 = ID+1 of processor that owns atom procp1 = ID+1 of processor that owns atom
type = atom type type = atom type
typelabel = atom :doc:`type label <Howto_type_labels>`
element = name of atom element, as defined by :doc:`dump_modify <dump_modify>` command element = name of atom element, as defined by :doc:`dump_modify <dump_modify>` command
mass = atom mass mass = atom mass
x,y,z = unscaled atom coordinates x,y,z = unscaled atom coordinates
@ -470,8 +471,9 @@ followed by one line per atom with the atom type and the :math:`x`-,
:math:`y`-, and :math:`z`-coordinate of that atom. You can use the :math:`y`-, and :math:`z`-coordinate of that atom. You can use the
:doc:`dump_modify element <dump_modify>` option to change the output :doc:`dump_modify element <dump_modify>` option to change the output
from using the (numerical) atom type to an element name (or some other from using the (numerical) atom type to an element name (or some other
label). This will help many visualization programs to guess bonds and label). This option will help many visualization programs to guess bonds
colors. and colors. You can use the :doc:`dump_modify types labels <dump_modify>`
option to replace numeric atom types with :doc:`type labels <Howto_type_labels>`.
.. versionadded:: 22Dec2022 .. versionadded:: 22Dec2022
@ -774,21 +776,21 @@ command creates a per-atom array with six columns:
Per-atom attributes used as arguments to the *custom* and *cfg* styles: Per-atom attributes used as arguments to the *custom* and *cfg* styles:
The *id*, *mol*, *proc*, *procp1*, *type*, *element*, *mass*, *vx*, The *id*, *mol*, *proc*, *procp1*, *type*, *typelabel*, *element*, *mass*,
*vy*, *vz*, *fx*, *fy*, *fz*, *q* attributes are self-explanatory. *vx*, *vy*, *vz*, *fx*, *fy*, *fz*, *q* attributes are self-explanatory.
*Id* is the atom ID. *Mol* is the molecule ID, included in the data *Id* is the atom ID. *Mol* is the molecule ID, included in the data file
file for molecular systems. *Proc* is the ID of the processor (0 to for molecular systems. *Proc* is the ID of the processor (0 to
:math:`N_\text{procs}-1`) that currently owns the atom. *Procp1* is the :math:`N_\text{procs}-1`) that currently owns the atom. *Procp1* is the
proc ID+1, which can be convenient in place of a *type* attribute (1 to proc ID+1, which can be convenient in place of a *type* attribute (1 to
:math:`N_\text{types}`) for coloring atoms in a visualization program. :math:`N_\text{types}`) for coloring atoms in a visualization program.
*Type* is the atom type (1 to :math:`N_\text{types}`). *Element* is *Type* is the atom type (1 to :math:`N_\text{types}`). *Typelabel* is the
typically the chemical name of an element, which you must assign to each atom :doc:`type label <Howto_type_labels>`. *Element* is typically the
type via the :doc:`dump_modify element <dump_modify>` command. More chemical name of an element, which you must assign to each type via the
generally, it can be any string you wish to associated with an atom :doc:`dump_modify element <dump_modify>` command. More generally, it can
type. *Mass* is the atom mass. The quantities *vx*, *vy*, *vz*, *fx*, be any string you wish to associated with an atom type. *Mass* is the atom
*fy*, *fz*, and *q* are components of atom velocity and force and atomic mass. The quantities *vx*, *vy*, *vz*, *fx*, *fy*, *fz*, and *q* are
charge. components of atom velocity and force and atomic charge.
There are several options for outputting atom coordinates. The *x*, There are several options for outputting atom coordinates. The *x*,
*y*, and *z* attributes write atom coordinates "unscaled", in the *y*, and *z* attributes write atom coordinates "unscaled", in the

View File

@ -17,7 +17,7 @@ Syntax
* one or more keyword/value pairs may be appended * one or more keyword/value pairs may be appended
* these keywords apply to various dump styles * these keywords apply to various dump styles
* keyword = *append* or *at* or *balance* or *buffer* or *colname* or *delay* or *element* or *every* or *every/time* or *fileper* or *first* or *flush* or *format* or *header* or *image* or *label* or *maxfiles* or *nfile* or *pad* or *pbc* or *precision* or *region* or *refresh* or *scale* or *sfactor* or *skip* or *sort* or *tfactor* or *thermo* or *thresh* or *time* or *triclinic/general* or *units* or *unwrap* * keyword = *append* or *at* or *balance* or *buffer* or *colname* or *delay* or *element* or *every* or *every/time* or *fileper* or *first* or *flush* or *format* or *header* or *image* or *label* or *maxfiles* or *nfile* or *pad* or *pbc* or *precision* or *region* or *refresh* or *scale* or *sfactor* or *skip* or *sort* or *tfactor* or *thermo* or *thresh* or *time* or *triclinic/general* or *types* or *units* or *unwrap*
.. parsed-literal:: .. parsed-literal::
@ -81,6 +81,7 @@ Syntax
these 3 args can be replaced by the word "none" to turn off thresholding these 3 args can be replaced by the word "none" to turn off thresholding
*time* arg = *yes* or *no* *time* arg = *yes* or *no*
*triclinic/general* arg = *yes* or *no* *triclinic/general* arg = *yes* or *no*
*types* value = *numeric* or *labels*
*units* arg = *yes* or *no* *units* arg = *yes* or *no*
*unwrap* arg = *yes* or *no* *unwrap* arg = *yes* or *no*
@ -849,6 +850,13 @@ The default setting is *no*\ .
---------- ----------
The *types* keyword applies only to the dump xyz style. If this keyword is
used with a value of *numeric*, then numeric atom types are printed in the
xyz file (default). If the value *labels* is specified, then
:doc:`type labels <Howto_type_labels>` are printed for atom types.
----------
The *triclinic/general* keyword only applies to the dump *atom* and The *triclinic/general* keyword only applies to the dump *atom* and
*custom* styles. It can only be used with a value of *yes* if the *custom* styles. It can only be used with a value of *yes* if the
simulation box was created as a general triclinic box. See the simulation box was created as a general triclinic box. See the
@ -960,11 +968,11 @@ The option defaults are
* sort = id for dump styles *dcd*, *xtc*, and *xyz* * sort = id for dump styles *dcd*, *xtc*, and *xyz*
* thresh = none * thresh = none
* time = no * time = no
* triclinic/general no * triclinic/general = no
* types = numeric
* units = no * units = no
* unwrap = no * unwrap = no
* compression_level = 9 (gz variants) * compression_level = 9 (gz variants)
* compression_level = 0 (zstd variants) * compression_level = 0 (zstd variants)
* checksum = yes (zstd variants) * checksum = yes (zstd variants)

View File

@ -1,18 +1,19 @@
.. index:: fitpod .. index:: fitpod
fitpod command fitpod command
====================== ==============
Syntax Syntax
"""""" """"""
.. code-block:: LAMMPS .. code-block:: LAMMPS
fitpod Ta_param.pod Ta_data.pod fitpod Ta_param.pod Ta_data.pod Ta_coefficients.pod
* fitpod = style name of this command * fitpod = style name of this command
* Ta_param.pod = an input file that describes proper orthogonal descriptors (PODs) * Ta_param.pod = an input file that describes proper orthogonal descriptors (PODs)
* Ta_data.pod = an input file that specifies DFT data used to fit a POD potential * Ta_data.pod = an input file that specifies DFT data used to fit a POD potential
* Ta_coefficients.pod (optional) = an input file that specifies trainable coefficients of a POD potential
Examples Examples
"""""""" """"""""
@ -20,20 +21,26 @@ Examples
.. code-block:: LAMMPS .. code-block:: LAMMPS
fitpod Ta_param.pod Ta_data.pod fitpod Ta_param.pod Ta_data.pod
fitpod Ta_param.pod Ta_data.pod Ta_coefficients.pod
Description Description
""""""""""" """""""""""
.. versionadded:: 22Dec2022 .. versionadded:: 22Dec2022
Fit a machine-learning interatomic potential (ML-IAP) based on proper Fit a machine-learning interatomic potential (ML-IAP) based on proper
orthogonal descriptors (POD). Two input files are required for this orthogonal descriptors (POD); please see :ref:`(Nguyen and Rohskopf)
command. The first input file describes a POD potential parameter <Nguyen20222a>`, :ref:`(Nguyen2023) <Nguyen20232a>`, :ref:`(Nguyen2024)
settings, while the second input file specifies the DFT data used for <Nguyen20242a>`, and :ref:`(Nguyen and Sema) <Nguyen20243a>` for details.
the fitting procedure. The fitted POD potential can be used to run MD simulations via
:doc:`pair_style pod <pair_pod>`.
The table below has one-line descriptions of all the keywords that can Two input files are required for this command. The first input file
be used in the first input file (i.e. ``Ta_param.pod`` in the example describes a POD potential parameter settings, while the second input
above): file specifies the DFT data used for the fitting procedure. All keywords
except *species* have default values. If a keyword is not set in the
input file, its default value is used. The table below has one-line
descriptions of all the keywords that can be used in the first input
file (i.e. ``Ta_param.pod``)
.. list-table:: .. list-table::
:header-rows: 1 :header-rows: 1
@ -52,7 +59,7 @@ above):
- INT - INT
- three integer constants specify boundary conditions - three integer constants specify boundary conditions
* - rin * - rin
- 1.0 - 0.5
- REAL - REAL
- a real number specifies the inner cut-off radius - a real number specifies the inner cut-off radius
* - rcut * - rcut
@ -60,46 +67,75 @@ above):
- REAL - REAL
- a real number specifies the outer cut-off radius - a real number specifies the outer cut-off radius
* - bessel_polynomial_degree * - bessel_polynomial_degree
- 3 - 4
- INT - INT
- the maximum degree of Bessel polynomials - the maximum degree of Bessel polynomials
* - inverse_polynomial_degree * - inverse_polynomial_degree
- 6 - 8
- INT - INT
- the maximum degree of inverse radial basis functions - the maximum degree of inverse radial basis functions
* - number_of_environment_clusters
- 1
- INT
- the number of clusters for environment-adaptive potentials
* - number_of_principal_components
- 2
- INT
- the number of principal components for dimensionality reduction
* - onebody * - onebody
- 1 - 1
- BOOL - BOOL
- turns on/off one-body potential - turns on/off one-body potential
* - twobody_number_radial_basis_functions * - twobody_number_radial_basis_functions
- 6 - 8
- INT - INT
- number of radial basis functions for two-body potential - number of radial basis functions for two-body potential
* - threebody_number_radial_basis_functions * - threebody_number_radial_basis_functions
- 5 - 6
- INT - INT
- number of radial basis functions for three-body potential - number of radial basis functions for three-body potential
* - threebody_number_angular_basis_functions * - threebody_angular_degree
- 5 - 5
- INT - INT
- number of angular basis functions for three-body potential - angular degree for three-body potential
* - fourbody_snap_twojmax * - fourbody_number_radial_basis_functions
- 4
- INT
- number of radial basis functions for four-body potential
* - fourbody_angular_degree
- 3
- INT
- angular degree for four-body potential
* - fivebody_number_radial_basis_functions
- 0 - 0
- INT - INT
- band limit for SNAP bispectrum components (0,2,4,6,8... allowed) - number of radial basis functions for five-body potential
* - fourbody_snap_chemflag * - fivebody_angular_degree
- 0 - 0
- BOOL - INT
- turns on/off the explicit multi-element variant of the SNAP bispectrum components - angular degree for five-body potential
* - quadratic_pod_potential * - sixbody_number_radial_basis_functions
- 0 - 0
- BOOL - INT
- turns on/off quadratic POD potential - number of radial basis functions for six-body potential
* - sixbody_angular_degree
- 0
- INT
- angular degree for six-body potential
* - sevenbody_number_radial_basis_functions
- 0
- INT
- number of radial basis functions for seven-body potential
* - sevenbody_angular_degree
- 0
- INT
- angular degree for seven-body potential
Note that both the number of radial basis functions and angular degree
must decrease as the body order increases. The next table describes all
keywords that can be used in the second input file (i.e. ``Ta_data.pod``
in the example above):
All keywords except *species* have default values. If a keyword is not
set in the input file, its default value is used. The next table
describes all keywords that can be used in the second input file
(i.e. ``Ta_data.pod`` in the example above):
.. list-table:: .. list-table::
:header-rows: 1 :header-rows: 1
@ -125,6 +161,10 @@ describes all keywords that can be used in the second input file
- "" - ""
- STRING - STRING
- specifies the path to test data files in double quotes - specifies the path to test data files in double quotes
* - path_to_environment_configuration_set
- ""
- STRING
- specifies the path to environment configuration files in double quotes
* - fraction_training_data_set * - fraction_training_data_set
- 1.0 - 1.0
- REAL - REAL
@ -133,6 +173,14 @@ describes all keywords that can be used in the second input file
- 0 - 0
- BOOL - BOOL
- turns on/off randomization of the training set - turns on/off randomization of the training set
* - fraction_test_data_set
- 1.0
- REAL
- a real number (<= 1.0) specifies the fraction of the test set used to validate POD
* - randomize_test_data_set
- 0
- BOOL
- turns on/off randomization of the test set
* - fitting_weight_energy * - fitting_weight_energy
- 100.0 - 100.0
- REAL - REAL
@ -161,6 +209,10 @@ describes all keywords that can be used in the second input file
- 8 - 8
- INT - INT
- number of digits after the decimal points for numbers in the coefficient file - number of digits after the decimal points for numbers in the coefficient file
* - group_weights
- global
- STRING
- ``table`` uses group weights defined for each group named by filename
All keywords except *path_to_training_data_set* have default values. If All keywords except *path_to_training_data_set* have default values. If
a keyword is not set in the input file, its default value is used. After a keyword is not set in the input file, its default value is used. After
@ -172,14 +224,44 @@ successful training, a number of output files are produced, if enabled:
* ``<basename>_test_analysis.pod`` reports detailed errors for all test configurations * ``<basename>_test_analysis.pod`` reports detailed errors for all test configurations
* ``<basename>_coefficients.pod`` contains the coefficients of the POD potential * ``<basename>_coefficients.pod`` contains the coefficients of the POD potential
After training the POD potential, ``Ta_param.pod`` and ``<basename>_coefficients.pod`` After training the POD potential, ``Ta_param.pod`` and
are the two files needed to use the POD potential in LAMMPS. See ``<basename>_coefficients.pod`` are the two files needed to use the POD
:doc:`pair_style pod <pair_pod>` for using the POD potential. Examples potential in LAMMPS. See :doc:`pair_style pod <pair_pod>` for using the
about training and using POD potentials are found in the directory POD potential. Examples about training and using POD potentials are
lammps/examples/PACKAGES/pod. found in the directory lammps/examples/PACKAGES/pod and the Github repo
https://github.com/cesmix-mit/pod-examples.
Parameterized Potential Energy Surface Loss Function Group Weights
"""""""""""""""""""""""""""""""""""""" ^^^^^^^^^^^^^^^^^^^^^^^^^^^
The *group_weights* keyword in the ``data.pod`` file is responsible for
weighting certain groups of configurations in the loss function. For
example:
.. code-block:: LAMMPS
group_weights table
Displaced_A15 100.0 1.0
Displaced_BCC 100.0 1.0
Displaced_FCC 100.0 1.0
Elastic_BCC 100.0 1.0
Elastic_FCC 100.0 1.0
GSF_110 100.0 1.0
GSF_112 100.0 1.0
Liquid 100.0 1.0
Surface 100.0 1.0
Volume_A15 100.0 1.0
Volume_BCC 100.0 1.0
Volume_FCC 100.0 1.0
This will apply an energy weight of ``100.0`` and a force weight of
``1.0`` for all groups in the ``Ta`` example. The groups are named by
their respective filename. If certain groups are left out of this table,
then the globally defined weights from the ``fitting_weight_energy`` and
``fitting_weight_force`` keywords will be used.
POD Potential
"""""""""""""
We consider a multi-element system of *N* atoms with :math:`N_{\rm e}` We consider a multi-element system of *N* atoms with :math:`N_{\rm e}`
unique elements. We denote by :math:`\boldsymbol r_n` and :math:`Z_n` unique elements. We denote by :math:`\boldsymbol r_n` and :math:`Z_n`
@ -187,535 +269,82 @@ position vector and type of an atom *n* in the system,
respectively. Note that we have :math:`Z_n \in \{1, \ldots, N_{\rm e} respectively. Note that we have :math:`Z_n \in \{1, \ldots, N_{\rm e}
\}`, :math:`\boldsymbol R = (\boldsymbol r_1, \boldsymbol r_2, \ldots, \}`, :math:`\boldsymbol R = (\boldsymbol r_1, \boldsymbol r_2, \ldots,
\boldsymbol r_N) \in \mathbb{R}^{3N}`, and :math:`\boldsymbol Z = (Z_1, \boldsymbol r_N) \in \mathbb{R}^{3N}`, and :math:`\boldsymbol Z = (Z_1,
Z_2, \ldots, Z_N) \in \mathbb{N}^{N}`. The potential energy surface Z_2, \ldots, Z_N) \in \mathbb{N}^{N}`. The total energy of the
(PES) of the system can be expressed as a many-body expansion of the POD potential is expressed as :math:`E(\boldsymbol R, \boldsymbol Z) =
form \sum_{i=1}^N E_i(\boldsymbol R_i, \boldsymbol Z_i)`, where
.. math:: .. math::
E(\boldsymbol R, \boldsymbol Z, \boldsymbol{\eta}, \boldsymbol{\mu}) \ = \ & \sum_{i} V^{(1)}(\boldsymbol r_i, Z_i, \boldsymbol \mu^{(1)} ) + \frac12 \sum_{i,j} V^{(2)}(\boldsymbol r_i, \boldsymbol r_j, Z_i, Z_j, \boldsymbol \eta, \boldsymbol \mu^{(2)}) \\ E_i(\boldsymbol R_i, \boldsymbol Z_i) \ = \ \sum_{m=1}^M c_m \mathcal{D}_{im}(\boldsymbol R_i, \boldsymbol Z_i)
& + \frac16 \sum_{i,j,k} V^{(3)}(\boldsymbol r_i, \boldsymbol r_j, \boldsymbol r_k, Z_i, Z_j, Z_k, \boldsymbol \eta, \boldsymbol \mu^{(3)}) + \ldots
where :math:`V^{(1)}` is the one-body potential often used for Here :math:`c_m` are trainable coefficients and
representing external field or energy of isolated elements, and the :math:`\mathcal{D}_{im}(\boldsymbol R_i, \boldsymbol Z_i)` are per-atom
higher-body potentials :math:`V^{(2)}, V^{(3)}, \ldots` are symmetric, POD descriptors. Summing the per-atom descriptors over :math:`i` yields
uniquely defined, and zero if two or more indices take identical values. the global descriptors :math:`d_m(\boldsymbol R, \boldsymbol Z) =
The superscript on each potential denotes its body order. Each *q*-body \sum_{i=1}^N \mathcal{D}_{im}(\boldsymbol R_i, \boldsymbol Z_i)`. It
potential :math:`V^{(q)}` depends on :math:`\boldsymbol \mu^{(q)}` which thus follows that :math:`E(\boldsymbol R, \boldsymbol Z) = \sum_{m=1}^M
are sets of parameters to fit the PES. Note that :math:`\boldsymbol \mu` c_m d_m(\boldsymbol R, \boldsymbol Z)`.
is a collection of all potential parameters :math:`\boldsymbol
\mu^{(1)}`, :math:`\boldsymbol \mu^{(2)}`, :math:`\boldsymbol The per-atom POD descriptors include one, two, three, four, five, six,
\mu^{(3)}`, etc, and that :math:`\boldsymbol \eta` is a set of and seven-body descriptors, which can be specified in the first input
hyper-parameters such as inner cut-off radius :math:`r_{\rm in}` and file. Furthermore, the per-atom POD descriptors also depend on the
outer cut-off radius :math:`r_{\rm cut}`. number of environment clusters specified in the first input file.
Please see :ref:`(Nguyen2024) <Nguyen20242a>` and :ref:`(Nguyen and Sema)
Interatomic potentials rely on parameters to learn relationship between <Nguyen20243a>` for the detailed description of the per-atom POD
atomic environments and interactions. Since interatomic potentials are descriptors.
approximations by nature, their parameters need to be set to some
reference values or fitted against data by necessity. Typically,
potential fitting finds optimal parameters, :math:`\boldsymbol \mu^*`,
to minimize a certain loss function of the predicted quantities and
data. Since the fitted potential depends on the data set used to fit it,
different data sets will yield different optimal parameters and thus
different fitted potentials. When fitting the same functional form on
*Q* different data sets, we would obtain *Q* different optimized
potentials, :math:`E(\boldsymbol R,\boldsymbol Z, \boldsymbol \eta,
\boldsymbol \mu_q^*), 1 \le q \le Q`. Consequently, there exist many
different sets of optimized parameters for empirical interatomic
potentials.
Instead of optimizing the potential parameters, inspired by the reduced
basis method :ref:`(Grepl) <Grepl20072>` for parameterized partial
differential equations, we view the parameterized PES as a parametric
manifold of potential energies
.. math::
\mathcal{M} = \{E(\boldsymbol R, \boldsymbol Z, \boldsymbol \eta, \boldsymbol \mu) \ | \ \boldsymbol \mu \in \Omega^{\boldsymbol \mu} \}
where :math:`\Omega^{\boldsymbol \mu}` is a parameter domain in which
:math:`\boldsymbol \mu` resides. The parametric manifold
:math:`\mathcal{M}` contains potential energy surfaces for all values of
:math:`\boldsymbol \mu \in \Omega^{\boldsymbol \mu}`. Therefore, the
parametric manifold yields a much richer and more transferable atomic
representation than any particular individual PES :math:`E(\boldsymbol
R, \boldsymbol Z, \boldsymbol \eta, \boldsymbol \mu^*)`.
We propose specific forms of the parameterized potentials for one-body,
two-body, and three-body interactions. We apply the Karhunen-Loeve
expansion to snapshots of the parameterized potentials to obtain sets of
orthogonal basis functions. These basis functions are aggregated
according to the chemical elements of atoms, thus leading to
multi-element proper orthogonal descriptors.
Proper Orthogonal Descriptors
"""""""""""""""""""""""""""""
Proper orthogonal descriptors are finger prints characterizing the
radial and angular distribution of a system of atoms. The detailed
mathematical definition is given in the paper by Nguyen and Rohskopf
:ref:`(Nguyen) <Nguyen20222>`.
The descriptors for the one-body interaction are used to capture energy
of isolated elements and defined as follows
.. math::
D_{ip}^{(1)} = \left\{
\begin{array}{ll}
1, & \mbox{if } Z_i = p \\
0, & \mbox{if } Z_i \neq p
\end{array}
\right.
for :math:`1 \le i \le N, 1 \le p \le N_{\rm e}`. The number of one-body
descriptors per atom is equal to the number of elements. The one-body
descriptors are independent of atom positions, but dependent on atom
types. The one-body descriptors are active only when the keyword
*onebody* is set to 1.
We adopt the usual assumption that the direct interaction between two
atoms vanishes smoothly when their distance is greater than the outer
cutoff distance :math:`r_{\rm cut}`. Furthermore, we assume that two
atoms can not get closer than the inner cutoff distance :math:`r_{\rm
in}` due to the Pauli repulsion principle. Let :math:`r \in (r_{\rm in},
r_{\rm cut})`, we introduce the following parameterized radial functions
.. math::
\phi(r, r_{\rm in}, r_{\rm cut}, \alpha, \beta) = \frac{\sin (\alpha \pi x) }{r - r_{\rm in}}, \qquad \varphi(r, \gamma) = \frac{1}{r^\gamma} ,
where the scaled distance function :math:`x` is defined below to enrich the two-body manifold
.. math::
x(r, r_{\rm in}, r_{\rm cut}, \beta) = \frac{e^{-\beta(r - r_{\rm in})/(r_{\rm cut} - r_{\rm in})} - 1}{e^{-\beta} - 1} .
We introduce the following function as a convex combination of the two functions
.. math::
\psi(r, r_{\rm in}, r_{\rm cut}, \alpha, \beta, \gamma, \kappa) = \kappa \phi(r, r_{\rm in}, r_{\rm cut}, \alpha, \beta) + (1- \kappa) \varphi(r, \gamma) .
We see that :math:`\psi` is a function of distance :math:`r`, cut-off
distances :math:`r_{\rm in}` and :math:`r_{\rm cut}`, and parameters
:math:`\alpha, \beta, \gamma, \kappa`. Together these parameters allow
the function :math:`\psi` to characterize a diverse spectrum of two-body
interactions within the cut-off interval :math:`(r_{\rm in}, r_{\rm
cut})`.
Next, we introduce the following parameterized potential
.. math::
W^{(2)}(r_{ij}, \boldsymbol \eta, \boldsymbol \mu^{(2)}) = f_{\rm c}(r_{ij}, \boldsymbol \eta) \psi(r_{ij}, \boldsymbol \eta, \boldsymbol \mu^{(2)})
where :math:`\eta_1 = r_{\rm in}, \eta_2 = r_{\rm cut}, \mu_1^{(2)} =
\alpha, \mu_2^{(2)} = \beta, \mu_3^{(2)} = \gamma`, and
:math:`\mu_4^{(2)} = \kappa`. Here the cut-off function :math:`f_{\rm
c}(r_{ij}, \boldsymbol \eta)` proposed in [refs] is used to ensure the
smooth vanishing of the potential and its derivative for :math:`r_{ij}
\ge r_{\rm cut}`:
.. math::
f_{\rm c}(r_{ij}, r_{\rm in}, r_{\rm cut}) = \exp \left(1 -\frac{1}{\sqrt{\left(1 - \frac{(r-r_{\rm in})^3}{(r_{\rm cut} - r_{\rm in})^3} \right)^2 + 10^{-6}}} \right)
Based on the parameterized potential, we form a set of snapshots as
follows. We assume that we are given :math:`N_{\rm s}` parameter tuples
:math:`\boldsymbol \mu^{(2)}_\ell, 1 \le \ell \le N_{\rm s}`. We
introduce the following set of snapshots on :math:`(r_{\rm in}, r_{\rm
cut})`:
.. math::
\xi_\ell(r_{ij}, \boldsymbol \eta) = W^{(2)}(r_{ij}, \boldsymbol \eta, \boldsymbol \mu^{(2)}_\ell), \quad \ell = 1, \ldots, N_{\rm s} .
To ensure adequate sampling of the PES for different parameters, we
choose :math:`N_{\rm s}` parameter points :math:`\boldsymbol
\mu^{(2)}_\ell = (\alpha_\ell, \beta_\ell, \gamma_\ell, \kappa_\ell), 1
\le \ell \le N_{\rm s}` as follows. The parameters :math:`\alpha \in [1,
N_\alpha]` and :math:`\gamma \in [1, N_\gamma]` are integers, where
:math:`N_\alpha` and :math:`N_\gamma` are the highest degrees for
:math:`\alpha` and :math:`\gamma`, respectively. We next choose
:math:`N_\beta` different values of :math:`\beta` in the interval
:math:`[\beta_{\min}, \beta_{\max}]`, where :math:`\beta_{\min} = 0` and
:math:`\beta_{\max} = 4`. The parameter :math:`\kappa` can be set either
0 or 1. Hence, the total number of parameter points is :math:`N_{\rm s}
= N_\alpha N_\beta + N_\gamma`. Although :math:`N_\alpha, N_\beta,
N_\gamma` can be chosen conservatively large, we find that
:math:`N_\alpha = 6, N_\beta = 3, N_\gamma = 8` are adequate for most
problems. Note that :math:`N_\alpha` and :math:`N_\gamma` correspond to
*bessel_polynomial_degree* and *inverse_polynomial_degree*,
respectively.
We employ the Karhunen-Loeve (KL) expansion to generate an orthogonal
basis set which is known to be optimal for representation of the
snapshot family :math:`\{\xi_\ell\}_{\ell=1}^{N_{\rm s}}`. The two-body
orthogonal basis functions are computed as follows
.. math::
U^{(2)}_m(r_{ij}, \boldsymbol \eta) = \sum_{\ell = 1}^{N_{\rm s}} A_{\ell m}(\boldsymbol \eta) \, \xi_\ell(r_{ij}, \boldsymbol \eta), \qquad m = 1, \ldots, N_{\rm 2b} ,
where the matrix :math:`\boldsymbol A \in \mathbb{R}^{N_{\rm s} \times
N_{\rm s}}` consists of eigenvectors of the eigenvalue problem
.. math::
\boldsymbol C \boldsymbol a = \lambda \boldsymbol a
with the entries of :math:`\boldsymbol C \in \mathbb{R}^{N_{\rm s} \times N_{\rm s}}` being given by
.. math::
C_{ij} = \frac{1}{N_{\rm s}} \int_{r_{\rm in}}^{r_{\rm cut}} \xi_i(x, \boldsymbol \eta) \xi_j(x, \boldsymbol \eta) dx, \quad 1 \le i, j \le N_{\rm s}
Note that the eigenvalues :math:`\lambda_\ell, 1 \le \ell \le N_{\rm
s}`, are ordered such that :math:`\lambda_1 \ge \lambda_2 \ge \ldots \ge
\lambda_{N_{\rm s}}`, and that the matrix :math:`\boldsymbol A` is
pe-computed and stored for any given :math:`\boldsymbol \eta`. Owing to
the rapid convergence of the KL expansion, only a small number of
orthogonal basis functions is needed to obtain accurate
approximation. The value of :math:`N_{\rm 2b}` corresponds to
*twobody_number_radial_basis_functions*.
The two-body proper orthogonal descriptors at each atom *i* are computed
by summing the orthogonal basis functions over the neighbors of atom *i*
and numerating on the atom types as follows
.. math::
D^{(2)}_{im l(p, q) }(\boldsymbol \eta) = \left\{
\begin{array}{ll}
\displaystyle \sum_{\{j | Z_j = q\}} U^{(2)}_m(r_{ij}, \boldsymbol \eta), & \mbox{if } Z_i = p \\
0, & \mbox{if } Z_i \neq p
\end{array}
\right.
for :math:`1 \le i \le N, 1 \le m \le N_{\rm 2b}, 1 \le q, p \le N_{\rm
e}`. Here :math:`l(p,q)` is a symmetric index mapping such that
.. math::
l(p,q) = \left\{
\begin{array}{ll}
q + (p-1) N_{\rm e} - p(p-1)/2, & \mbox{if } q \ge p \\
p + (q-1) N_{\rm e} - q(q-1)/2, & \mbox{if } q < p .
\end{array}
\right.
The number of two-body descriptors per atom is thus :math:`N_{\rm 2b}
N_{\rm e}(N_{\rm e}+1)/2`.
It is important to note that the orthogonal basis functions do not
depend on the atomic numbers :math:`Z_i` and :math:`Z_j`. Therefore, the
cost of evaluating the basis functions and their derivatives with
respect to :math:`r_{ij}` is independent of the number of elements
:math:`N_{\rm e}`. Consequently, even though the two-body proper
orthogonal descriptors depend on :math:`\boldsymbol Z`, their
computational complexity is independent of :math:`N_{\rm e}`.
In order to provide proper orthogonal descriptors for three-body
interactions, we need to introduce a three-body parameterized
potential. In particular, the three-body potential is defined as a
product of radial and angular functions as follows
.. math::
W^{(3)}(r_{ij}, r_{ik}, \theta_{ijk}, \boldsymbol \eta, \boldsymbol \mu^{(3)}) = \psi(r_{ij}, r_{\rm min}, r_{\rm max}, \alpha, \beta, \gamma, \kappa) f_{\rm c}(r_{ij}, r_{\rm min}, r_{\rm max}) \\
\psi(r_{ik}, r_{\rm min}, r_{\rm max}, \alpha, \beta, \gamma, \kappa) f_{\rm c}(r_{ik}, r_{\rm min}, r_{\rm max}) \\
\cos (\sigma \theta_{ijk} + \zeta)
where :math:`\sigma` is the periodic multiplicity, :math:`\zeta` is the
equilibrium angle, :math:`\boldsymbol \mu^{(3)} = (\alpha, \beta,
\gamma, \kappa, \sigma, \zeta)`. The three-body potential provides an
angular fingerprint of the atomic environment through the bond angles
:math:`\theta_{ijk}` formed with each pair of neighbors :math:`j` and
:math:`k`. Compared to the two-body potential, the three-body potential
has two extra parameters :math:`(\sigma, \zeta)` associated with the
angular component.
Let :math:`\boldsymbol \varrho = (\alpha, \beta, \gamma, \kappa)`. We
assume that we are given :math:`L_{\rm r}` parameter tuples
:math:`\boldsymbol \varrho_\ell, 1 \le \ell \le L_{\rm r}`. We
introduce the following set of snapshots on :math:`(r_{\min},
r_{\max})`:
.. math::
\zeta_\ell(r_{ij}, r_{\rm min}, r_{\rm max} ) = \psi(r_{ij}, r_{\rm min}, r_{\rm max}, \boldsymbol \varrho_\ell) f_{\rm c}(r_{ij}, r_{\rm min}, r_{\rm max}), \quad 1 \le \ell \le L_{\rm r} .
We apply the Karhunen-Loeve (KL) expansion to this set of snapshots to
obtain orthogonal basis functions as follows
.. math::
U^{r}_m(r_{ij}, r_{\rm min}, r_{\rm max} ) = \sum_{\ell = 1}^{L_{\rm r}} A_{\ell m} \, \zeta_\ell(r_{ij}, r_{\rm min}, r_{\rm max} ), \qquad m = 1, \ldots, N_{\rm r} ,
where the matrix :math:`\boldsymbol A \in \mathbb{R}^{L_{\rm r} \times L_{\rm r}}` consists
of eigenvectors of the eigenvalue problem. For the parameterized angular function,
we consider angular basis functions
.. math::
U^{a}_n(\theta_{ijk}) = \cos ((n-1) \theta_{ijk}), \qquad n = 1,\ldots, N_{\rm a},
where :math:`N_{\rm a}` is the number of angular basis functions. The orthogonal
basis functions for the parameterized potential are computed as follows
.. math::
U^{(3)}_{mn}(r_{ij}, r_{ik}, \theta_{ijk}, \boldsymbol \eta) = U^{r}_m(r_{ij}, \boldsymbol \eta) U^{r}_m(r_{ik}, \boldsymbol \eta) U^{a}_n(\theta_{ijk}),
for :math:`1 \le m \le N_{\rm r}, 1 \le n \le N_{\rm a}`. The number of three-body
orthogonal basis functions is equal to :math:`N_{\rm 3b} = N_{\rm r} N_{\rm a}` and
independent of the number of elements. The value of :math:`N_{\rm r}` corresponds to
*threebody_number_radial_basis_functions*, while that of :math:`N_{\rm a}` to
*threebody_number_angular_basis_functions*.
The three-body proper orthogonal descriptors at each atom *i*
are obtained by summing over the neighbors *j* and *k* of atom *i* as
.. math::
D^{(3)}_{imn \ell(p, q, s)}(\boldsymbol \eta) = \left\{
\begin{array}{ll}
\displaystyle \sum_{\{j | Z_j = q\}} \sum_{\{k | Z_k = s\}} U^{(3)}_{mn}(r_{ij}, r_{ik}, \theta_{ijk}, \boldsymbol \eta), & \mbox{if } Z_i = p \\
0, & \mbox{if } Z_i \neq p
\end{array}
\right.
for :math:`1 \le i \le N, 1 \le m \le N_{\rm r}, 1 \le n \le N_{\rm a}, 1 \le q, p, s \le N_{\rm e}`,
where
.. math::
\ell(p,q,s) = \left\{
\begin{array}{ll}
s + (q-1) N_{\rm e} - q(q-1)/2 + (p-1)N_{\rm e}(1+N_{\rm e})/2 , & \mbox{if } s \ge q \\
q + (s-1) N_{\rm e} - s(s-1)/2 + (p-1)N_{\rm e}(1+N_{\rm e})/2, & \mbox{if } s < q .
\end{array}
\right.
The number of three-body descriptors per atom is thus :math:`N_{\rm 3b} N_{\rm e}^2(N_{\rm e}+1)/2`.
While the number of three-body PODs is cubic function of the number of elements,
the computational complexity of the three-body PODs is independent of the number of elements.
Four-Body SNAP Descriptors
""""""""""""""""""""""""""
In addition to the proper orthogonal descriptors described above, we also employ
the spectral neighbor analysis potential (SNAP) descriptors. SNAP uses bispectrum components
to characterize the local neighborhood of each atom in a very general way. The mathematical definition
of the bispectrum calculation and its derivatives w.r.t. atom positions is described in
:doc:`compute snap <compute_sna_atom>`. In SNAP, the
total energy is decomposed into a sum over atom energies. The energy of
atom *i* is expressed as a weighted sum over bispectrum components.
.. math::
E_i^{\rm SNAP} = \sum_{k=1}^{N_{\rm 4b}} \sum_{p=1}^{N_{\rm e}} c_{kp}^{(4)} D_{ikp}^{(4)}
where the SNAP descriptors are related to the bispectrum components by
.. math::
D^{(4)}_{ikp} = \left\{
\begin{array}{ll}
\displaystyle B_{ik}, & \mbox{if } Z_i = p \\
0, & \mbox{if } Z_i \neq p
\end{array}
\right.
Here :math:`B_{ik}` is the *k*\ -th bispectrum component of atom *i*. The number of
bispectrum components :math:`N_{\rm 4b}` depends on the value of *fourbody_snap_twojmax* :math:`= 2 J_{\rm max}`
and *fourbody_snap_chemflag*. If *fourbody_snap_chemflag* = 0
then :math:`N_{\rm 4b} = (J_{\rm max}+1)(J_{\rm max}+2)(J_{\rm max}+1.5)/3`.
If *fourbody_snap_chemflag* = 1 then :math:`N_{\rm 4b} = N_{\rm e}^3 (J_{\rm max}+1)(J_{\rm max}+2)(J_{\rm max}+1.5)/3`.
The bispectrum calculation is described in more detail in :doc:`compute sna/atom <compute_sna_atom>`.
Linear Proper Orthogonal Descriptor Potentials
""""""""""""""""""""""""""""""""""""""""""""""
The proper orthogonal descriptors and SNAP descriptors are used to define the atomic energies
in the following expansion
.. math::
E_{i}(\boldsymbol \eta) = \sum_{p=1}^{N_{\rm e}} c^{(1)}_p D^{(1)}_{ip} + \sum_{m=1}^{N_{\rm 2b}} \sum_{l=1}^{N_{\rm e}(N_{\rm e}+1)/2} c^{(2)}_{ml} D^{(2)}_{iml}(\boldsymbol \eta) + \sum_{m=1}^{N_{\rm r}} \sum_{n=1}^{N_{\rm a}} \sum_{\ell=1}^{N_{\rm e}^2(N_{\rm e}+1)/2} c^{(3)}_{mn\ell} D^{(3)}_{imn\ell}(\boldsymbol \eta) + \sum_{k=1}^{N_{\rm 4b}} \sum_{p=1}^{N_{\rm e}} c_{kp}^{(4)} D_{ikp}^{(4)}(\boldsymbol \eta),
where :math:`D^{(1)}_{ip}, D^{(2)}_{iml}, D^{(3)}_{imn\ell}, D^{(4)}_{ikp}` are the one-body, two-body, three-body, four-body descriptors,
respectively, and :math:`c^{(1)}_p, c^{(2)}_{ml}, c^{(3)}_{mn\ell}, c^{(4)}_{kp}` are their respective expansion
coefficients. In a more compact notation that implies summation over descriptor indices
the atomic energies can be written as
.. math::
E_i(\boldsymbol \eta) = \sum_{m=1}^{N_{\rm e}} c^{(1)}_m D^{(1)}_{im} + \sum_{m=1}^{N_{\rm d}^{(2)}} c^{(2)}_k D^{(2)}_{im} + \sum_{m=1}^{N_{\rm d}^{(3)}} c^{(3)}_m D^{(3)}_{im} + \sum_{m=1}^{N_{\rm d}^{(4)}} c^{(4)}_m D^{(4)}_{im}
where :math:`N_{\rm d}^{(2)} = N_{\rm 2b} N_{\rm e} (N_{\rm e}+1)/2`,
:math:`N_{\rm d}^{(3)} = N_{\rm 3b} N_{\rm e}^2 (N_{\rm e}+1)/2`, and
:math:`N_{\rm d}^{(4)} = N_{\rm 4b} N_{\rm e}` are
the number of two-body, three-body, and four-body descriptors, respectively.
The potential energy is then obtained by summing local atomic energies :math:`E_i`
for all atoms :math:`i` in the system
.. math::
E(\boldsymbol \eta) = \sum_{i}^N E_{i}(\boldsymbol \eta)
Because the descriptors are one-body, two-body, and three-body terms,
the resulting POD potential is a three-body PES. We can express the potential
energy as a linear combination of the global descriptors as follows
.. math::
E(\boldsymbol \eta) = \sum_{m=1}^{N_{\rm e}} c^{(1)}_m d^{(1)}_{m} + \sum_{m=1}^{N_{\rm d}^{(2)}} c^{(2)}_m d^{(2)}_{m} + \sum_{m=1}^{N_{\rm d}^{(3)}} c^{(3)}_m d^{(3)}_{m} + \sum_{m=1}^{N_{\rm d}^{(4)}} c^{(4)}_m d^{(4)}_{m}
where the global descriptors are given by
.. math::
d_{m}^{(1)}(\boldsymbol \eta) = \sum_{i=1}^N D_{im}^{(1)}(\boldsymbol \eta), \quad d_{m}^{(2)}(\boldsymbol \eta) = \sum_{i=1}^N D_{im}^{(2)}(\boldsymbol \eta), \quad d_{m}^{(3)}(\boldsymbol \eta) = \sum_{i=1}^N D_{im}^{(3)}(\boldsymbol \eta), \quad d_{m}^{(4)}(\boldsymbol \eta) = \sum_{i=1}^N D_{im}^{(4)}(\boldsymbol \eta)
Hence, we obtain the atomic forces as
.. math::
\boldsymbol F = -\nabla E(\boldsymbol \eta) = - \sum_{m=1}^{N_{\rm d}^{(2)}} c^{(2)}_m \nabla d_m^{(2)} - \sum_{m=1}^{N_{\rm d}^{(3)}} c^{(3)}_m \nabla d_m^{(3)} - \sum_{m=1}^{N_{\rm d}^{(4)}} c^{(4)}_m \nabla d_m^{(4)}
where :math:`\nabla d_m^{(2)}`, :math:`\nabla d_m^{(3)}` and :math:`\nabla d_m^{(4)}` are derivatives of the two-body
three-body, and four-body global descriptors with respect to atom positions, respectively.
Note that since the first-body global descriptors are constant, their derivatives are zero.
Quadratic Proper Orthogonal Descriptor Potentials
"""""""""""""""""""""""""""""""""""""""""""""""""
We recall two-body PODs :math:`D^{(2)}_{ik}, 1 \le k \le N_{\rm d}^{(2)}`,
and three-body PODs :math:`D^{(3)}_{im}, 1 \le m \le N_{\rm d}^{(3)}`,
with :math:`N_{\rm d}^{(2)} = N_{\rm 2b} N_{\rm e} (N_{\rm e}+1)/2` and
:math:`N_{\rm d}^{(3)} = N_{\rm 3b} N_{\rm e}^2 (N_{\rm e}+1)/2` being
the number of descriptors per atom for the two-body PODs and three-body PODs,
respectively. We employ them to define a new set of atomic descriptors as follows
.. math::
D^{(2*3)}_{ikm} = \frac{1}{2N}\left( D^{(2)}_{ik} \sum_{j=1}^N D^{(3)}_{jm} + D^{(3)}_{im} \sum_{j=1}^N D^{(2)}_{jk} \right)
for :math:`1 \le i \le N, 1 \le k \le N_{\rm d}^{(2)}, 1 \le m \le N_{\rm d}^{(3)}`.
The new descriptors are four-body because they involve central atom :math:`i` together
with three neighbors :math:`j, k` and :math:`l`. The total number of new descriptors per atom is equal to
.. math::
N_{\rm d}^{(2*3)} = N_{\rm d}^{(2)} * N_{\rm d}^{(3)} = N_{\rm 2b} N_{\rm 3b} N_{\rm e}^3 (N_{\rm e}+1)^2/4 .
The new global descriptors are calculated as
.. math::
d^{(2*3)}_{km} = \sum_{i=1}^N D^{(2*3)}_{ikm} = \left( \sum_{i=1}^N D^{(2)}_{ik} \right) \left( \sum_{i=1}^N D^{(3)}_{im} \right) = d^{(2)}_{k} d^{(3)}_m,
for :math:`1 \le k \le N_{\rm d}^{(2)}, 1 \le m \le N_{\rm d}^{(3)}`. Hence, the gradient
of the new global descriptors with respect to atom positions is calculated as
.. math::
\nabla d^{(2*3)}_{km} = d^{(3)}_m \nabla d^{(2)}_{k} + d^{(2)}_{k} \nabla d^{(3)}_m, \quad 1 \le k \le N_{\rm d}^{(2)}, 1 \le m \le N_{\rm d}^{(3)} .
The quadratic POD potential is defined as a linear combination of the
original and new global descriptors as follows
.. math::
E^{(2*3)} = \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} c^{(2*3)}_{km} d^{(2*3)}_{km} .
It thus follows that
.. math::
E^{(2*3)} = 0.5 \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} \left( \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} c^{(2*3)}_{km} d_m^{(3)} \right) d_k^{(2)} + 0.5 \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} \left( \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} c^{(2*3)}_{km} d_k^{(2)} \right) d_m^{(3)} ,
which is simplified to
.. math::
E^{(2*3)} = 0.5 \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} b_k^{(2)} d_k^{(2)} + 0.5 \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} b_m^{(3)} d_m^{(3)}
where
.. math::
b_k^{(2)} & = \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} c^{(2*3)}_{km} d_m^{(3)}, \quad k = 1,\ldots, N_{\rm 2d}^{(2*3)}, \\
b_m^{(3)} & = \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} c^{(2*3)}_{km} d_k^{(2)}, \quad m = 1,\ldots, N_{\rm 3d}^{(2*3)} .
The quadratic POD potential results in the following atomic forces
.. math::
\boldsymbol F^{(2*3)} = - \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} c^{(2*3)}_{km} \nabla d^{(2*3)}_{km} .
It can be shown that
.. math::
\boldsymbol F^{(2*3)} = - \sum_{k=1}^{N_{\rm 2d}^{(2*3)}} b^{(2)}_k \nabla d_k^{(2)} - \sum_{m=1}^{N_{\rm 3d}^{(2*3)}} b^{(3)}_m \nabla d_m^{(3)} .
The calculation of the atomic forces for the quadratic POD potential
only requires the extra calculation of :math:`b_k^{(2)}` and :math:`b_m^{(3)}` which can be negligible.
As a result, the quadratic POD potential does not increase the computational complexity.
Training Training
"""""""" """"""""
POD potentials are trained using the least-squares regression against A POD potential is trained using the least-squares regression against
density functional theory (DFT) data. Let :math:`J` be the number of density functional theory (DFT) data. Let :math:`J` be the number of
training configurations, with :math:`N_j` being the number of atoms in training configurations, with :math:`N_j` being the number of atoms in
the j-th configuration. Let :math:`\{E^{\star}_j\}_{j=1}^{J}` and the j-th configuration. The training configurations are extracted from
:math:`\{\boldsymbol F^{\star}_j\}_{j=1}^{J}` be the DFT energies and the extended XYZ files located in a directory (i.e.,
forces for :math:`J` configurations. Next, we calculate the global path_to_training_data_set in the second input file). Let
descriptors and their derivatives for all training configurations. Let :math:`\{E^{\star}_j\}_{j=1}^{J}` and :math:`\{\boldsymbol
:math:`d_{jm}, 1 \le m \le M`, be the global descriptors associated with F^{\star}_j\}_{j=1}^{J}` be the DFT energies and forces for :math:`J`
the j-th configuration, where :math:`M` is the number of global configurations. Next, we calculate the global descriptors and their
descriptors. We then form a matrix :math:`\boldsymbol A \in derivatives for all training configurations. Let :math:`d_{jm}, 1 \le m
\mathbb{R}^{J \times M}` with entries :math:`A_{jm} = d_{jm}/ N_j` for \le M`, be the global descriptors associated with the j-th
:math:`j=1,\ldots,J` and :math:`m=1,\ldots,M`. Moreover, we form a configuration, where :math:`M` is the number of global descriptors. We
matrix :math:`\boldsymbol B \in \mathbb{R}^{\mathcal{N} \times M}` by then form a matrix :math:`\boldsymbol A \in \mathbb{R}^{J \times M}`
stacking the derivatives of the global descriptors for all training with entries :math:`A_{jm} = d_{jm}/ N_j` for :math:`j=1,\ldots,J` and
configurations from top to bottom, where :math:`\mathcal{N} = :math:`m=1,\ldots,M`. Moreover, we form a matrix :math:`\boldsymbol B
3\sum_{j=1}^{J} N_j`. \in \mathbb{R}^{\mathcal{N} \times M}` by stacking the derivatives of
the global descriptors for all training configurations from top to
bottom, where :math:`\mathcal{N} = 3\sum_{j=1}^{J} N_j`.
The coefficient vector :math:`\boldsymbol c` of the POD potential is The coefficient vector :math:`\boldsymbol c` of the POD potential is
found by solving the following least-squares problem found by solving the following least-squares problem
.. math:: .. math::
{\min}_{\boldsymbol c \in \mathbb{R}^{M}} \ w_E \|\boldsymbol A(\boldsymbol \eta) \boldsymbol c - \bar{\boldsymbol E}^{\star} \|^2 + w_F \|\boldsymbol B(\boldsymbol \eta) \boldsymbol c + \boldsymbol F^{\star} \|^2 + w_R \|\boldsymbol c \|^2, {\min}_{\boldsymbol c \in \mathbb{R}^{M}} \ w_E \|\boldsymbol A \boldsymbol c - \bar{\boldsymbol E}^{\star} \|^2 + w_F \|\boldsymbol B \boldsymbol c + \boldsymbol F^{\star} \|^2 + w_R \|\boldsymbol c \|^2,
where :math:`w_E` and :math:`w_F` are weights for the energy where :math:`w_E` and :math:`w_F` are weights for the energy
(*fitting_weight_energy*) and force (*fitting_weight_force*), (*fitting_weight_energy*) and force (*fitting_weight_force*),
respectively; and :math:`w_R` is the regularization parameter (*fitting_regularization_parameter*). Here :math:`\bar{\boldsymbol E}^{\star} \in respectively; and :math:`w_R` is the regularization parameter
\mathbb{R}^{J}` is a vector of with entries :math:`\bar{E}^{\star}_j = (*fitting_regularization_parameter*). Here :math:`\bar{\boldsymbol
E^{\star}_j/N_j` and :math:`\boldsymbol F^{\star}` is a vector of E}^{\star} \in \mathbb{R}^{J}` is a vector of with entries
:math:`\mathcal{N}` entries obtained by stacking :math:`\{\boldsymbol :math:`\bar{E}^{\star}_j = E^{\star}_j/N_j` and :math:`\boldsymbol
F^{\star}_j\}_{j=1}^{J}` from top to bottom. F^{\star}` is a vector of :math:`\mathcal{N}` entries obtained by
stacking :math:`\{\boldsymbol F^{\star}_j\}_{j=1}^{J}` from top to
bottom.
The training procedure is the same for both the linear and quadratic POD Validation
potentials. However, since the quadratic POD potential has a """"""""""
significantly larger number of the global descriptors, it is more
expensive to train the linear POD potential. This is because the
training of the quadratic POD potential still requires us to calculate
and store the quadratic global descriptors and their
gradient. Furthermore, the quadratic POD potential may require more
training data in order to prevent over-fitting. In order to reduce the
computational cost of fitting the quadratic POD potential and avoid
over-fitting, we can use subsets of two-body and three-body PODs for
constructing the new descriptors.
POD potential can be validated on a test dataset in a directory
specified by setting path_to_test_data_set in the second input file. It
is possible to validate the POD potential after the training is
complete. This is done by providing the coefficient file as an input to
:doc:`fitpod <fitpod_command>`, for example,
.. code-block:: LAMMPS
fitpod Ta_param.pod Ta_data.pod Ta_coefficients.pod
Restrictions Restrictions
"""""""""""" """"""""""""
@ -727,7 +356,11 @@ LAMMPS was built with that package. See the :doc:`Build package
Related commands Related commands
"""""""""""""""" """"""""""""""""
:doc:`pair_style pod <pair_pod>` :doc:`pair_style pod <pair_pod>`,
:doc:`compute pod/atom <compute_pod_atom>`,
:doc:`compute podd/atom <compute_pod_atom>`,
:doc:`compute pod/local <compute_pod_atom>`,
:doc:`compute pod/global <compute_pod_atom>`
Default Default
""""""" """""""
@ -736,10 +369,20 @@ The keyword defaults are also given in the description of the input files.
---------- ----------
.. _Grepl20072: .. _Nguyen20222a:
**(Grepl)** Grepl, Maday, Nguyen, and Patera, ESAIM: Mathematical Modelling and Numerical Analysis 41(3), 575-605, (2007). **(Nguyen and Rohskopf)** Nguyen and Rohskopf, Journal of Computational Physics, 480, 112030, (2023).
.. _Nguyen20232a:
**(Nguyen2023)** Nguyen, Physical Review B, 107(14), 144103, (2023).
.. _Nguyen20242a:
**(Nguyen2024)** Nguyen, Journal of Computational Physics, 113102, (2024).
.. _Nguyen20243a:
**(Nguyen and Sema)** Nguyen and Sema, https://arxiv.org/abs/2405.00306, (2024).
.. _Nguyen20222:
**(Nguyen)** Nguyen and Rohskopf, arXiv preprint arXiv:2209.02362 (2022).

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@ -21,17 +21,17 @@ Syntax
*pair* args = pstyle pparam I J v_name *pair* args = pstyle pparam I J v_name
pstyle = pair style name (e.g., lj/cut) pstyle = pair style name (e.g., lj/cut)
pparam = parameter to adapt over time pparam = parameter to adapt over time
I,J = type pair(s) to set parameter for I,J = type pair(s) to set parameter for (integer or type label)
v_name = variable with name that calculates value of pparam v_name = variable with name that calculates value of pparam
*bond* args = bstyle bparam I v_name *bond* args = bstyle bparam I v_name
bstyle = bond style name (e.g., harmonic) bstyle = bond style name (e.g., harmonic)
bparam = parameter to adapt over time bparam = parameter to adapt over time
I = type bond to set parameter for I = type bond to set parameter for (integer or type label)
v_name = variable with name that calculates value of bparam v_name = variable with name that calculates value of bparam
*angle* args = astyle aparam I v_name *angle* args = astyle aparam I v_name
astyle = angle style name (e.g., harmonic) astyle = angle style name (e.g., harmonic)
aparam = parameter to adapt over time aparam = parameter to adapt over time
I = type angle to set parameter for I = type angle to set parameter for (integer or type label)
v_name = variable with name that calculates value of aparam v_name = variable with name that calculates value of aparam
*kspace* arg = v_name *kspace* arg = v_name
v_name = variable with name that calculates scale factor on :math:`k`-space terms v_name = variable with name that calculates scale factor on :math:`k`-space terms
@ -67,6 +67,9 @@ Examples
variable ramp_up equal "ramp(0.01,0.5)" variable ramp_up equal "ramp(0.01,0.5)"
fix stretch all adapt 1 bond harmonic r0 1 v_ramp_up fix stretch all adapt 1 bond harmonic r0 1 v_ramp_up
labelmap atom 1 c1
fix 1 all adapt 1 pair soft a c1 c1 v_prefactor
Description Description
""""""""""" """""""""""
@ -254,10 +257,12 @@ should be specified to indicate which type pairs to apply it to. If a global
parameter is specified, the :math:`I` and :math:`J` settings still need to be parameter is specified, the :math:`I` and :math:`J` settings still need to be
specified, but are ignored. specified, but are ignored.
Similar to the :doc:`pair_coeff command <pair_coeff>`, :math:`I` and :math:`J` Similar to the :doc:`pair_coeff command <pair_coeff>`, :math:`I` and
can be specified in one of two ways. Explicit numeric values can be used for :math:`J` can be specified in one of several ways. Explicit numeric values
each, as in the first example above. :math:`I \le J` is required. LAMMPS sets can be used for each, as in the first example above. Or, one or both of
the coefficients for the symmetric :math:`J,I` interaction to the same values. the types in the I,J pair can be a :doc:`type label <Howto_type_labels>`.
LAMMPS sets the coefficients for the symmetric :math:`J,I` interaction to
the same values.
A wild-card asterisk can be used in place of or in conjunction with A wild-card asterisk can be used in place of or in conjunction with
the :math:`I,J` arguments to set the coefficients for multiple pairs of atom the :math:`I,J` arguments to set the coefficients for multiple pairs of atom
@ -266,8 +271,9 @@ is the number of atom types, then an asterisk with no numeric values
means all types from 1 to :math:`N`. A leading asterisk means all types from means all types from 1 to :math:`N`. A leading asterisk means all types from
1 to n (inclusive). A trailing asterisk means all types from m to :math:`N` 1 to n (inclusive). A trailing asterisk means all types from m to :math:`N`
(inclusive). A middle asterisk means all types from m to n (inclusive). A middle asterisk means all types from m to n
(inclusive). Note that only type pairs with :math:`I \le J` are considered; if (inclusive). For the asterisk syntax, note that only type pairs with
asterisks imply type pairs where :math:`J < I`, they are ignored. :math:`I \le J` are considered; if asterisks imply type pairs where
:math:`J < I`, they are ignored.
IMPORTANT NOTE: If :doc:`pair_style hybrid or hybrid/overlay IMPORTANT NOTE: If :doc:`pair_style hybrid or hybrid/overlay
<pair_hybrid>` is being used, then the *pstyle* will be a sub-style <pair_hybrid>` is being used, then the *pstyle* will be a sub-style

View File

@ -21,13 +21,13 @@ Syntax
*pair* args = pstyle pparam I J v_name *pair* args = pstyle pparam I J v_name
pstyle = pair style name (e.g., lj/cut) pstyle = pair style name (e.g., lj/cut)
pparam = parameter to adapt over time pparam = parameter to adapt over time
I,J = type pair(s) to set parameter for I,J = type pair(s) to set parameter for (integer or type label)
v_name = variable with name that calculates value of pparam v_name = variable with name that calculates value of pparam
*kspace* arg = v_name *kspace* arg = v_name
v_name = variable with name that calculates scale factor on K-space terms v_name = variable with name that calculates scale factor on K-space terms
*atom* args = aparam v_name *atom* args = aparam v_name
aparam = parameter to adapt over time aparam = parameter to adapt over time
I = type(s) to set parameter for I = type(s) to set parameter for (integer or type label)
v_name = variable with name that calculates value of aparam v_name = variable with name that calculates value of aparam
* zero or more keyword/value pairs may be appended * zero or more keyword/value pairs may be appended
@ -56,6 +56,9 @@ Examples
fix 1 all adapt/fep 1 pair lj/cut epsilon * * v_scale1 coul/cut scale 3 3 v_scale2 scale yes reset yes fix 1 all adapt/fep 1 pair lj/cut epsilon * * v_scale1 coul/cut scale 3 3 v_scale2 scale yes reset yes
fix 1 all adapt/fep 10 atom diameter 1 v_size fix 1 all adapt/fep 10 atom diameter 1 v_size
labelmap atom 1 c1
fix 1 all adapt/fep 1 pair soft a c1 c1 v_prefactor
Example input scripts available: examples/PACKAGES/fep Example input scripts available: examples/PACKAGES/fep
@ -218,10 +221,12 @@ be specified to indicate which type pairs to apply it to. If a global
parameter is specified, the *I* and *J* settings still need to be parameter is specified, the *I* and *J* settings still need to be
specified, but are ignored. specified, but are ignored.
Similar to the :doc:`pair_coeff command <pair_coeff>`, I and J can be Similar to the :doc:`pair_coeff command <pair_coeff>`, :math:`I` and
specified in one of two ways. Explicit numeric values can be used for :math:`J` can be specified in one of several ways. Explicit numeric values
each, as in the first example above. :math:`I \le J` is required. LAMMPS sets can be used for each, as in the first example above. Or, one or both of
the coefficients for the symmetric J,I interaction to the same values. the types in the I,J pair can be a :doc:`type label <Howto_type_labels>`.
LAMMPS sets the coefficients for the symmetric :math:`J,I` interaction to
the same values.
A wild-card asterisk can be used in place of or in conjunction with A wild-card asterisk can be used in place of or in conjunction with
the :math:`I,J` arguments to set the coefficients for multiple pairs of atom the :math:`I,J` arguments to set the coefficients for multiple pairs of atom
@ -230,8 +235,9 @@ the number of atom types, then an asterisk with no numeric values means
all types from 1 to :math:`N`. A leading asterisk means all types from 1 to n all types from 1 to :math:`N`. A leading asterisk means all types from 1 to n
(inclusive). A trailing asterisk means all types from m to :math:`N` (inclusive). A trailing asterisk means all types from m to :math:`N`
(inclusive). A middle asterisk means all types from m to n (inclusive). A middle asterisk means all types from m to n
(inclusive). Note that only type pairs with :math:`I \le J` are considered; if (inclusive). For the asterisk syntax, note that only type pairs with
asterisks imply type pairs where :math:`J < I`, they are ignored. :math:`I \le J` are considered; if asterisks imply type pairs where
:math:`J < I`, they are ignored.
IMPROTANT NOTE: If :doc:`pair_style hybrid or hybrid/overlay <pair_hybrid>` is IMPROTANT NOTE: If :doc:`pair_style hybrid or hybrid/overlay <pair_hybrid>` is
being used, then the *pstyle* will be a sub-style name. You must specify being used, then the *pstyle* will be a sub-style name. You must specify

View File

@ -35,7 +35,11 @@ the implementation of AMOEBA and HIPPO in LAMMPS.
Bitorsion interactions add additional potential energy contributions Bitorsion interactions add additional potential energy contributions
to pairs of overlapping phi-psi dihedrals of amino-acids, which are to pairs of overlapping phi-psi dihedrals of amino-acids, which are
important to properly represent their conformational behavior. important to properly represent their conformational behavior. Each
bitorsion interaction is thus defined for a 5-tuple of atoms
:math:`IJKLM` with bonds between successive atoms in the list,
i.e. two overlapping dihedral interactions for atoms :math:`IJKL` and
:math:`JKLM`.
The examples/amoeba directory has a sample input script and data file The examples/amoeba directory has a sample input script and data file
for ubiquitin, which illustrates use of the fix amoeba/bitorsion for ubiquitin, which illustrates use of the fix amoeba/bitorsion
@ -68,14 +72,15 @@ lines:
[...] [...]
N 3 314 315 317 318 330 N 3 314 315 317 318 330
The first column is an index from 1 to :math:`N` to enumerate the bitorsion The first column is an index from 1 to :math:`N` to enumerate the
5-atom tuples; it is ignored by LAMMPS. The second column is the bitorsion 5-atom tuples; it is ignored by LAMMPS. The second column
*type* of the interaction; it is an index into the bitorsion force is the *type* of the interaction; it is an index into the bitorsion
field file. The remaining 5 columns are the atom IDs of the atoms in force field file. The remaining 5 columns are the atom IDs of the
the two 4-atom dihedrals that overlap to create the bitorsion 5-body atoms (in order) for the 5-tuple :math:`IJKLM`, as described above.
interaction. Note that the *bitorsions* and *BiTorsions* keywords for
the header and body sections match those specified in the Note that the *bitorsions* and *BiTorsions* keywords for the header
:doc:`read_data <read_data>` command following the data file name. and body sections match those specified in the :doc:`read_data
<read_data>` command following the data file name.
The data file should be generated by using the The data file should be generated by using the
tools/tinker/tinker2lmp.py conversion script which creates a LAMMPS tools/tinker/tinker2lmp.py conversion script which creates a LAMMPS

View File

@ -57,7 +57,7 @@ should have two lines like these in its header section:
M pitorsion types M pitorsion types
N pitorsions N pitorsions
where :math:`N` is the number of pitorsion 5-body interactions and :math:`M` is where :math:`N` is the number of pitorsion 6-body interactions and :math:`M` is
the number of pitorsion types. It should also have two sections in the body the number of pitorsion types. It should also have two sections in the body
of the data file like these with :math:`M` and :math:`N` lines each: of the data file like these with :math:`M` and :math:`N` lines each:
@ -74,21 +74,20 @@ of the data file like these with :math:`M` and :math:`N` lines each:
PiTorsions PiTorsions
1 1 8 10 12 18 20 1 1 2 4 3 20 21 24
2 5 18 20 22 25 27 2 5 21 23 22 37 38 41
[...] [...]
N 3 314 315 317 318 330 N 7 27 29 28 30 35 36
For PiTorsion Coeffs, the first column is an index from 1 to :math:`M` to For PiTorsion Coeffs, the first column is an index from 1 to :math:`M`
enumerate the pitorsion types. The second column is the single to enumerate the pitorsion types. The second column is the single
prefactor coefficient needed for each type. prefactor coefficient needed for each type.
For PiTorsions, the first column is an index from 1 to :math:`N` to enumerate For PiTorsions, the first column is an index from 1 to :math:`N` to
the pitorsion 5-atom tuples; it is ignored by LAMMPS. The second enumerate the pitorsion 6-atom tuples; it is ignored by LAMMPS. The
column is the "type" of the interaction; it is an index into the second column is the "type" of the interaction; it is an index into
PiTorsion Coeffs. The remaining 5 columns are the atom IDs of the the PiTorsion Coeffs. The remaining 6 columns are the atom IDs of the
atoms in the two 4-atom dihedrals that overlap to create the pitorsion atoms (in order) for the 6-tuple :math:`IJKLMN`, as described above.
5-body interaction.
Note that the *pitorsion types* and *pitorsions* and *PiTorsion Note that the *pitorsion types* and *pitorsions* and *PiTorsion
Coeffs* and *PiTorsions* keywords for the header and body sections of Coeffs* and *PiTorsions* keywords for the header and body sections of

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@ -21,7 +21,7 @@ Syntax
.. parsed-literal:: .. parsed-literal::
*types* values = two or more atom types *types* values = two or more atom types (1-Ntypes or type label)
*mu* values = chemical potential of swap types (energy units) *mu* values = chemical potential of swap types (energy units)
*ke* value = *no* or *yes* *ke* value = *no* or *yes*
*no* = no conservation of kinetic energy after atom swaps *no* = no conservation of kinetic energy after atom swaps
@ -168,7 +168,7 @@ the following global cumulative quantities:
* 1 = swap attempts * 1 = swap attempts
* 2 = swap accepts * 2 = swap accepts
The vector values calculated by this fix are "extensive". The vector values calculated by this fix are "intensive".
No parameter of this fix can be used with the *start/stop* keywords of No parameter of this fix can be used with the *start/stop* keywords of
the :doc:`run <run>` command. This fix is not invoked during the :doc:`run <run>` command. This fix is not invoked during

View File

@ -13,7 +13,7 @@ Syntax
* ID, group-ID are documented in :doc:`fix <fix>` command * ID, group-ID are documented in :doc:`fix <fix>` command
* bond/break = style name of this fix command * bond/break = style name of this fix command
* Nevery = attempt bond breaking every this many steps * Nevery = attempt bond breaking every this many steps
* bondtype = type of bonds to break * bondtype = type of bonds to break (integer or type label)
* Rmax = bond longer than Rmax can break (distance units) * Rmax = bond longer than Rmax can break (distance units)
* zero or more keyword/value pairs may be appended * zero or more keyword/value pairs may be appended
* keyword = *prob* * keyword = *prob*

View File

@ -17,9 +17,9 @@ Syntax
* ID, group-ID are documented in :doc:`fix <fix>` command * ID, group-ID are documented in :doc:`fix <fix>` command
* bond/create = style name of this fix command * bond/create = style name of this fix command
* Nevery = attempt bond creation every this many steps * Nevery = attempt bond creation every this many steps
* itype,jtype = atoms of itype can bond to atoms of jtype * itype,jtype = atoms of itype can bond to atoms of jtype (1-Ntypes or type label)
* Rmin = 2 atoms separated by less than Rmin can bond (distance units) * Rmin = 2 atoms separated by less than Rmin can bond (distance units)
* bondtype = type of created bonds * bondtype = type of created bonds (integer or type label)
* zero or more keyword/value pairs may be appended to args * zero or more keyword/value pairs may be appended to args
* keyword = *iparam* or *jparam* or *prob* or *atype* or *dtype* or *itype* or *aconstrain* * keyword = *iparam* or *jparam* or *prob* or *atype* or *dtype* or *itype* or *aconstrain*
@ -27,19 +27,19 @@ Syntax
*iparam* values = maxbond, newtype *iparam* values = maxbond, newtype
maxbond = max # of bonds of bondtype the itype atom can have maxbond = max # of bonds of bondtype the itype atom can have
newtype = change the itype atom to this type when maxbonds exist newtype = change the itype atom to this type when maxbonds exist (1-Ntypes or type label)
*jparam* values = maxbond, newtype *jparam* values = maxbond, newtype
maxbond = max # of bonds of bondtype the jtype atom can have maxbond = max # of bonds of bondtype the jtype atom can have
newtype = change the jtype atom to this type when maxbonds exist newtype = change the jtype atom to this type when maxbonds exist (1-Ntypes or type label)
*prob* values = fraction seed *prob* values = fraction seed
fraction = create a bond with this probability if otherwise eligible fraction = create a bond with this probability if otherwise eligible
seed = random number seed (positive integer) seed = random number seed (positive integer)
*atype* value = angletype *atype* value = angletype
angletype = type of created angles angletype = type of created angles (integer or type label)
*dtype* value = dihedraltype *dtype* value = dihedraltype
dihedraltype = type of created dihedrals dihedraltype = type of created dihedrals (integer or type label)
*itype* value = impropertype *itype* value = impropertype
impropertype = type of created impropers impropertype = type of created impropers (integer or type label)
*aconstrain* value = amin amax *aconstrain* value = amin amax
amin = minimal angle at which new bonds can be created amin = minimal angle at which new bonds can be created
amax = maximal angle at which new bonds can be created amax = maximal angle at which new bonds can be created
@ -54,6 +54,10 @@ Examples
fix 5 all bond/create 1 3 3 0.8 1 prob 0.5 85784 iparam 2 3 atype 1 dtype 2 fix 5 all bond/create 1 3 3 0.8 1 prob 0.5 85784 iparam 2 3 atype 1 dtype 2
fix 5 all bond/create/angle 10 1 2 1.122 1 aconstrain 120 180 prob 1 4928459 iparam 2 1 jparam 2 2 fix 5 all bond/create/angle 10 1 2 1.122 1 aconstrain 120 180 prob 1 4928459 iparam 2 1 jparam 2 2
labelmap atom 1 c1 2 n2
labelmap bond 1 c1-n2
fix 5 all bond/create 10 c1 n2 0.8 c1-n2
Description Description
""""""""""" """""""""""

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@ -13,8 +13,8 @@ Syntax
* ID, group-ID are documented in fix command * ID, group-ID are documented in fix command
* charge/regulation = style name of this fix command * charge/regulation = style name of this fix command
* cation_type = atom type of free cations * cation_type = atom type of free cations (integer or type label)
* anion_type = atom type of free anions * anion_type = atom type of free anions (integer or type label)
* zero or more keyword/value pairs may be appended * zero or more keyword/value pairs may be appended
@ -27,8 +27,8 @@ Syntax
*pIp* value = activity (effective concentration) of free cations (in the -log10 representation) *pIp* value = activity (effective concentration) of free cations (in the -log10 representation)
*pIm* value = activity (effective concentration) of free anions (in the -log10 representation) *pIm* value = activity (effective concentration) of free anions (in the -log10 representation)
*pKs* value = solvent self-dissociation constant (in the -log10 representation) *pKs* value = solvent self-dissociation constant (in the -log10 representation)
*acid_type* = atom type of acid groups *acid_type* = atom type of acid groups (integer or type label)
*base_type* = atom type of base groups *base_type* = atom type of base groups (integer or type label)
*lunit_nm* value = unit length used by LAMMPS (# in the units of nanometers) *lunit_nm* value = unit length used by LAMMPS (# in the units of nanometers)
*temp* value = temperature *temp* value = temperature
*tempfixid* value = fix ID of temperature thermostat *tempfixid* value = fix ID of temperature thermostat
@ -51,6 +51,9 @@ Examples
fix chareg all charge/regulation 1 2 acid_type 3 base_type 4 pKa 5.0 pKb 6.0 pH 7.0 pIp 3.0 pIm 3.0 nevery 200 nmc 200 seed 123 tempfixid fT fix chareg all charge/regulation 1 2 acid_type 3 base_type 4 pKa 5.0 pKb 6.0 pH 7.0 pIp 3.0 pIm 3.0 nevery 200 nmc 200 seed 123 tempfixid fT
fix chareg all charge/regulation 1 2 pIp 3 pIm 3 onlysalt yes 2 -1 seed 123 tag yes temp 1.0 fix chareg all charge/regulation 1 2 pIp 3 pIm 3 onlysalt yes 2 -1 seed 123 tag yes temp 1.0
labelmap atom 1 H+ 2 OH-
fix chareg all charge/regulation H+ OH- pIp 3 pIm 3 onlysalt yes 2 -1 seed 123 tag yes temp 1.0
Description Description
""""""""""" """""""""""

View File

@ -64,6 +64,8 @@ Syntax
effectively an engineering shear strain rate effectively an engineering shear strain rate
*erate* value = R *erate* value = R
R = engineering shear strain rate (1/time units) R = engineering shear strain rate (1/time units)
*erate/rescale* value = R (ONLY available in :doc:`fix deform/pressure <fix_deform_pressure>` command)
R = engineering shear strain rate (1/time units)
*trate* value = R *trate* value = R
R = true shear strain rate (1/time units) R = true shear strain rate (1/time units)
*wiggle* values = A Tp *wiggle* values = A Tp

View File

@ -29,10 +29,12 @@ Syntax
NOTE: All other styles are documented by the :doc:`fix deform <fix_deform>` command NOTE: All other styles are documented by the :doc:`fix deform <fix_deform>` command
*xy*, *xz*, *yz* args = style value *xy*, *xz*, *yz* args = style value
style = *final* or *delta* or *vel* or *erate* or *trate* or *wiggle* or *variable* or *pressure* style = *final* or *delta* or *vel* or *erate* or *trate* or *wiggle* or *variable* or *pressure* or *erate/rescale*
*pressure* values = target gain *pressure* values = target gain
target = target pressure (pressure units) target = target pressure (pressure units)
gain = proportional gain constant (1/(time * pressure) or 1/time units) gain = proportional gain constant (1/(time * pressure) or 1/time units)
*erate/rescale* value = R
R = engineering shear strain rate (1/time units)
NOTE: All other styles are documented by the :doc:`fix deform <fix_deform>` command NOTE: All other styles are documented by the :doc:`fix deform <fix_deform>` command
*box* = style value *box* = style value
@ -159,6 +161,21 @@ details of a simulation and testing different values is
recommended. One can also apply a maximum limit to the magnitude of recommended. One can also apply a maximum limit to the magnitude of
the applied strain using the :ref:`max/rate <deform_max_rate>` option. the applied strain using the :ref:`max/rate <deform_max_rate>` option.
The *erate/rescale* style operates similarly to the *erate* style with
a specified strain rate in units of 1/time. The difference is that
the change in the tilt factor will depend on the current length of
the box perpendicular to the shear direction, L, instead of the
original length, L0. The tilt factor T as a function of time will
change as
.. parsed-literal::
T(t) = T(t-1) + L\*erate\* \Delta t
where T(t-1) is the tilt factor on the previous timestep and :math:`\Delta t`
is the timestep size. This option may be useful in scenarios where
L changes in time.
---------- ----------
The *box* parameter provides an additional control over the *x*, *y*, The *box* parameter provides an additional control over the *x*, *y*,
@ -294,6 +311,10 @@ This fix is not invoked during :doc:`energy minimization <minimize>`.
Restrictions Restrictions
"""""""""""" """"""""""""
This fix is part of the EXTRA-FIX package. It is only enabled if LAMMPS
was built with that package. See the :doc:`Build package <Build_package>`
page for more info.
You cannot apply x, y, or z deformations to a dimension that is You cannot apply x, y, or z deformations to a dimension that is
shrink-wrapped via the :doc:`boundary <boundary>` command. shrink-wrapped via the :doc:`boundary <boundary>` command.

View File

@ -13,7 +13,7 @@ Syntax
* ID, group-ID are documented in :doc:`fix <fix>` command * ID, group-ID are documented in :doc:`fix <fix>` command
* deposit = style name of this fix command * deposit = style name of this fix command
* N = # of atoms or molecules to insert * N = # of atoms or molecules to insert
* type = atom type to assign to inserted atoms (offset for molecule insertion) * type = atom type (1-Ntypes or type label) to assign to inserted atoms (offset for molecule insertion)
* M = insert a single atom or molecule every M steps * M = insert a single atom or molecule every M steps
* seed = random # seed (positive integer) * seed = random # seed (positive integer)
* one or more keyword/value pairs may be appended to args * one or more keyword/value pairs may be appended to args
@ -76,6 +76,9 @@ Examples
fix 4 sputter deposit 1000 2 500 12235 region sphere vz -1.0 -1.0 target 5.0 5.0 0.0 units lattice fix 4 sputter deposit 1000 2 500 12235 region sphere vz -1.0 -1.0 target 5.0 5.0 0.0 units lattice
fix 5 insert deposit 200 2 100 777 region disk gaussian 5.0 5.0 9.0 1.0 units box fix 5 insert deposit 200 2 100 777 region disk gaussian 5.0 5.0 9.0 1.0 units box
labelmap atom 1 Au
fix 4 sputter deposit 1000 Au 500 12235 region sphere vz -1.0 -1.0 target 5.0 5.0 0.0 units lattice
Description Description
""""""""""" """""""""""

View File

@ -15,7 +15,7 @@ Syntax
* N = invoke this fix every N steps * N = invoke this fix every N steps
* X = average number of GCMC exchanges to attempt every N steps * X = average number of GCMC exchanges to attempt every N steps
* M = average number of MC moves to attempt every N steps * M = average number of MC moves to attempt every N steps
* type = atom type for inserted atoms (must be 0 if mol keyword used) * type = atom type (1-Ntypes or type label) for inserted atoms (must be 0 if mol keyword used)
* seed = random # seed (positive integer) * seed = random # seed (positive integer)
* T = temperature of the ideal gas reservoir (temperature units) * T = temperature of the ideal gas reservoir (temperature units)
* mu = chemical potential of the ideal gas reservoir (energy units) * mu = chemical potential of the ideal gas reservoir (energy units)
@ -45,7 +45,7 @@ Syntax
*group* value = group-ID *group* value = group-ID
group-ID = group-ID for inserted atoms (string) group-ID = group-ID for inserted atoms (string)
*grouptype* values = type group-ID *grouptype* values = type group-ID
type = atom type (int) type = atom type (1-Ntypes or type label)
group-ID = group-ID for inserted atoms (string) group-ID = group-ID for inserted atoms (string)
*intra_energy* value = intramolecular energy (energy units) *intra_energy* value = intramolecular energy (energy units)
*tfac_insert* value = scale up/down temperature of inserted atoms (unitless) *tfac_insert* value = scale up/down temperature of inserted atoms (unitless)
@ -62,52 +62,47 @@ Examples
fix 3 water gcmc 10 100 100 0 3456543 3.0 -2.5 0.1 mol my_one_water maxangle 180 full_energy fix 3 water gcmc 10 100 100 0 3456543 3.0 -2.5 0.1 mol my_one_water maxangle 180 full_energy
fix 4 my_gas gcmc 1 10 10 1 123456543 300.0 -12.5 1.0 region disk fix 4 my_gas gcmc 1 10 10 1 123456543 300.0 -12.5 1.0 region disk
labelmap atom 1 Li
fix 2 ion gcmc 10 1000 1000 Li 29494 298.0 -0.5 0.01
Description Description
""""""""""" """""""""""
This fix performs grand canonical Monte Carlo (GCMC) exchanges of This fix performs grand canonical Monte Carlo (GCMC) exchanges of atoms or
atoms or molecules with an imaginary ideal gas molecules with an imaginary ideal gas reservoir at the specified T and
reservoir at the specified T and chemical potential (mu) as discussed chemical potential (mu) as discussed in :ref:`(Frenkel) <Frenkel2>`. It
in :ref:`(Frenkel) <Frenkel2>`. It also also attempts Monte Carlo (MC) moves (translations and molecule rotations)
attempts Monte Carlo (MC) moves (translations and molecule within the simulation cell or region. If used with the :doc:`fix nvt <fix_nh>`
rotations) within the simulation cell or
region. If used with the :doc:`fix nvt <fix_nh>`
command, simulations in the grand canonical ensemble (muVT, constant command, simulations in the grand canonical ensemble (muVT, constant
chemical potential, constant volume, and constant temperature) can be chemical potential, constant volume, and constant temperature) can be
performed. Specific uses include computing isotherms in microporous performed. Specific uses include computing isotherms in microporous
materials, or computing vapor-liquid coexistence curves. materials, or computing vapor-liquid coexistence curves.
Every N timesteps the fix attempts both GCMC exchanges Every N timesteps the fix attempts both GCMC exchanges (insertions or
(insertions or deletions) and MC moves of gas atoms or molecules. deletions) and MC moves of gas atoms or molecules. On those timesteps, the
On those timesteps, the average number of attempted GCMC exchanges is X, average number of attempted GCMC exchanges is X, while the average number
while the average number of attempted MC moves is M. of attempted MC moves is M. For GCMC exchanges of either molecular or
For GCMC exchanges of either molecular or atomic gasses, atomic gasses, these exchanges can be either deletions or insertions, with
these exchanges can be either deletions or insertions, equal probability.
with equal probability.
The possible choices for MC moves are translation of an atom, The possible choices for MC moves are translation of an atom, translation
translation of a molecule, and rotation of a molecule. of a molecule, and rotation of a molecule. The relative amounts of each are
The relative amounts of each are determined by the optional determined by the optional *mcmoves* keyword (see below). The default
*mcmoves* keyword (see below). behavior is as follows. If the *mol* keyword is used, only molecule
The default behavior is as follows. translations and molecule rotations are performed with equal probability.
If the *mol* keyword is used, only molecule translations Conversely, if the *mol* keyword is not used, only atom translations are
and molecule rotations are performed with equal probability. performed. M should typically be chosen to be approximately equal to the
Conversely, if the *mol* keyword is not used, only atom expected number of gas atoms or molecules of the given type within the
translations are performed. simulation cell or region, which will result in roughly one MC move per
M should typically be atom or molecule per MC cycle.
chosen to be approximately equal to the expected number of gas atoms
or molecules of the given type within the simulation cell or region,
which will result in roughly one MC move per atom or molecule
per MC cycle.
All inserted particles are always added to two groups: the default All inserted particles are always added to two groups: the default group
group "all" and the fix group specified in the fix command. "all" and the fix group specified in the fix command. In addition,
In addition, particles are also added to any groups particles are also added to any groups specified by the *group* and
specified by the *group* and *grouptype* keywords. If inserted *grouptype* keywords. If inserted particles are individual atoms, they are
particles are individual atoms, they are assigned the atom type given assigned the atom type given by the type argument. If they are molecules,
by the type argument. If they are molecules, the type argument has no the type argument has no effect and must be set to zero. Instead, the type
effect and must be set to zero. Instead, the type of each atom in the of each atom in the inserted molecule is specified in the file read by the
inserted molecule is specified in the file read by the
:doc:`molecule <molecule>` command. :doc:`molecule <molecule>` command.
.. note:: .. note::
@ -427,7 +422,7 @@ the following global cumulative quantities:
* 7 = rotation attempts * 7 = rotation attempts
* 8 = rotation successes * 8 = rotation successes
The vector values calculated by this fix are "extensive". The vector values calculated by this fix are "intensive".
No parameter of this fix can be used with the *start/stop* keywords of No parameter of this fix can be used with the *start/stop* keywords of
the :doc:`run <run>` command. This fix is not invoked during the :doc:`run <run>` command. This fix is not invoked during

View File

@ -512,8 +512,7 @@ Value 27 computes the average boost for biased bonds only on this step.
Value 28 is the count of bonds with an absolute value of strain >= q Value 28 is the count of bonds with an absolute value of strain >= q
on this step. on this step.
The scalar value is an "extensive" quantity since it grows with the The scalar value and vector values are all "intensive".
system size; the vector values are all "intensive".
This fix also computes a local vector of length the number of bonds This fix also computes a local vector of length the number of bonds
currently in the system. The value for each bond is its :math:`C_{ij}` currently in the system. The value for each bond is its :math:`C_{ij}`

View File

@ -35,23 +35,24 @@ Description
""""""""""" """""""""""
This fix enables LAMMPS to be run as a client for the i-PI Python This fix enables LAMMPS to be run as a client for the i-PI Python
wrapper :ref:`(IPI) <ipihome>` for performing a path integral molecular dynamics wrapper :ref:`(IPI) <ipihome>`. i-PI is a universal force engine,
(PIMD) simulation. The philosophy behind i-PI is described in the designed to perform advanced molecular simulations, with a special
following publication :ref:`(IPI-CPC) <IPICPC>`. focus on path integral molecular dynamics (PIMD) simulation.
The philosophy behind i-PI is to separate the evaluation of the
energy and forces, which is delegated to the client, and the evolution
of the dynamics, that is the responsibility of i-PI. This approach also
simplifies combining energies computed from different codes, which
can for instance be useful to mix first-principles calculations,
empirical force fields or machine-learning potentials.
The following publication :ref:`(IPI-CPC-2014) <IPICPC>` discusses the
overall implementation of i-PI, and focuses on path-integral techniques,
while a later release :ref:`(IPI-CPC-2019) <IPICPC2>` introduces several
additional features and simulation schemes.
A version of the i-PI package, containing only files needed for use The communication between i-PI and LAMMPS takes place using sockets,
with LAMMPS, is provided in the tools/i-pi directory. See the and is reduced to the bare minimum. All the parameters of the dynamics
tools/i-pi/manual.pdf for an introduction to i-PI. The are specified in the input of i-PI, and all the parameters of the force
examples/PACKAGES/i-pi directory contains example scripts for using i-PI field must be specified as LAMMPS inputs, preceding the *fix ipi* command.
with LAMMPS.
In brief, the path integral molecular dynamics is performed by the
Python wrapper, while the client (LAMMPS in this case) simply computes
forces and energy for each configuration. The communication between
the two components takes place using sockets, and is reduced to the
bare minimum. All the parameters of the dynamics are specified in the
input of i-PI, and all the parameters of the force field must be
specified as LAMMPS inputs, preceding the *fix ipi* command.
The server address must be specified by the *address* argument, and The server address must be specified by the *address* argument, and
can be either the IP address, the fully-qualified name of the server, can be either the IP address, the fully-qualified name of the server,
@ -75,6 +76,20 @@ If the cell varies too wildly, it may be advisable to re-initialize
these interactions at each call. This behavior can be requested by these interactions at each call. This behavior can be requested by
setting the *reset* switch. setting the *reset* switch.
Obtaining i-PI
""""""""""""""
Here are the commands to set up a virtual environment and install
i-PI into it with all its dependencies via the PyPI repository and
the pip package manager.
.. code-block:: sh
python -m venv ipienv
source ipienv/bin/activate
pip install --upgrade pip
pip install ipi
Restart, fix_modify, output, run start/stop, minimize info Restart, fix_modify, output, run start/stop, minimize info
""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""""""""""""""""""""""""""""""""""""""
@ -111,9 +126,14 @@ Related commands
.. _IPICPC: .. _IPICPC:
**(IPI-CPC)** Ceriotti, More and Manolopoulos, Comp Phys Comm, 185, **(IPI-CPC-2014)** Ceriotti, More and Manolopoulos, Comp Phys Comm 185,
1019-1026 (2014). 1019-1026 (2014).
.. _IPICPC2:
**(IPI-CPC-2019)** Kapil et al., Comp Phys Comm 236, 214-223 (2019).
.. _ipihome: .. _ipihome:
**(IPI)** **(IPI)**

View File

@ -14,7 +14,7 @@ Syntax
* atom/swap = style name of this fix command * atom/swap = style name of this fix command
* N = invoke this fix every N steps * N = invoke this fix every N steps
* X = number of swaps to attempt every N steps * X = number of swaps to attempt every N steps
* itype,jtype = two atom types to swap with each other * itype,jtype = two atom types (1-Ntypes or type label) to swap with each other
* seed = random # seed (positive integer) * seed = random # seed (positive integer)
* T = scaling temperature of the MC swaps (temperature units) * T = scaling temperature of the MC swaps (temperature units)
* zero or more keyword/value pairs may be appended to args * zero or more keyword/value pairs may be appended to args
@ -34,6 +34,9 @@ Examples
fix 2 all mol/swap 100 1 2 3 29494 300.0 ke no fix 2 all mol/swap 100 1 2 3 29494 300.0 ke no
fix mySwap fluid mol/swap 500 10 1 2 482798 1.0 fix mySwap fluid mol/swap 500 10 1 2 482798 1.0
labelmap atom 1 A 2 B
fix mySwap fluid mol/swap 500 10 A B 482798 1.0
Description Description
""""""""""" """""""""""
@ -146,7 +149,7 @@ the following global cumulative quantities:
* 1 = swap attempts * 1 = swap attempts
* 2 = swap accepts * 2 = swap accepts
The vector values calculated by this fix are "extensive". The vector values calculated by this fix are "intensive".
No parameter of this fix can be used with the *start/stop* keywords of No parameter of this fix can be used with the *start/stop* keywords of
the :doc:`run <run>` command. This fix is not invoked during the :doc:`run <run>` command. This fix is not invoked during

View File

@ -8,7 +8,7 @@ Syntax
.. parsed-literal:: .. parsed-literal::
fix ID group nonaffine/displacement style args reference/style nstep fix ID group nonaffine/displacement style args reference/style nstep keyword values
* ID, group are documented in :doc:`fix <fix>` command * ID, group are documented in :doc:`fix <fix>` command
* nonaffine/displacement = style name of this fix command * nonaffine/displacement = style name of this fix command
@ -32,6 +32,13 @@ Syntax
*update* = update the reference frame every *nstep* timesteps *update* = update the reference frame every *nstep* timesteps
*offset* = update the reference frame *nstep* timesteps before calculating the nonaffine displacement *offset* = update the reference frame *nstep* timesteps before calculating the nonaffine displacement
* zero or more keyword/value pairs may be appended
.. parsed-literal::
*z/min* values = zmin
zmin = minimum coordination number to calculate D2min
Examples Examples
"""""""" """"""""
@ -76,6 +83,12 @@ is the identity tensor. This calculation is only performed on timesteps that
are a multiple of *nevery* (including timestep zero). Data accessed before are a multiple of *nevery* (including timestep zero). Data accessed before
this occurs will simply be zeroed. this occurs will simply be zeroed.
For particles with low coordination numbers, calculations of :math:`D^2_\mathrm{min}`
may not be accurate. An optional minimum coordination number can be defined using
the *z/min* keyword. If any particle has fewer than the specified number of particles
in the cutoff distance or in contact, the above calculations will be skipped and the
corresponding peratom array entries will be zero.
The *integrated* style simply integrates the velocity of particles The *integrated* style simply integrates the velocity of particles
every timestep to calculate a displacement. This style only works if every timestep to calculate a displacement. This style only works if
used in conjunction with another fix that deforms the box and displaces used in conjunction with another fix that deforms the box and displaces

View File

@ -20,7 +20,7 @@ Syntax
* Nfreq = calculate average bond-order every this many timesteps * Nfreq = calculate average bond-order every this many timesteps
* filename = name of output file * filename = name of output file
* zero or more keyword/value pairs may be appended * zero or more keyword/value pairs may be appended
* keyword = *cutoff* or *element* or *position* or *delete* * keyword = *cutoff* or *element* or *position* or *delete* or *delete_rate_limit*
.. parsed-literal:: .. parsed-literal::
@ -110,10 +110,10 @@ all types from 1 to :math:`N`. A leading asterisk means all types from
The optional keyword *element* can be used to specify the chemical The optional keyword *element* can be used to specify the chemical
symbol printed for each LAMMPS atom type. The number of symbols must symbol printed for each LAMMPS atom type. The number of symbols must
match the number of LAMMPS atom types and each symbol must consist of match the number of LAMMPS atom types and each symbol must consist of
1 or 2 alphanumeric characters. Normally, these symbols should be 1 or 2 alphanumeric characters. By default, these symbols are the same
chosen to match the chemical identity of each LAMMPS atom type, as as the chemical identity of each LAMMPS atom type, as specified by the
specified using the :doc:`reaxff pair_coeff <pair_reaxff>` command and :doc:`ReaxFF pair_coeff <pair_reaxff>` command and the ReaxFF force
the ReaxFF force field file. field file.
The optional keyword *position* writes center-of-mass positions of The optional keyword *position* writes center-of-mass positions of
each identified molecules to file *filepos* every *posfreq* timesteps. each identified molecules to file *filepos* every *posfreq* timesteps.
@ -134,36 +134,34 @@ value. For example, AuO.pos.\* becomes AuO.pos.0, AuO.pos.1000, etc.
.. versionadded:: 3Aug2022 .. versionadded:: 3Aug2022
The optional keyword *delete* enables the periodic removal of The optional keyword *delete* enables the periodic removal of molecules
molecules from the system. Criteria for deletion can be either a list from the system :ref:`(Gissinger) <Delete>`. Criteria for deletion can
of specific chemical formulae or a range of molecular weights. be either a list of specific chemical formulae or a range of molecular
Molecules are deleted every *Nfreq* timesteps, and bond connectivity weights. Molecules are deleted every *Nfreq* timesteps, and bond
is determined using the *Nevery* and *Nrepeat* keywords. The connectivity is determined using the *Nevery* and *Nrepeat* keywords. The
*filedel* argument is the name of the output file that records the *filedel* argument is the name of the output file that records the species
species that are removed from the system. The *specieslist* keyword that are removed from the system. The *specieslist* keyword permits
permits specific chemical species to be deleted. The *Nspecies* specific chemical species to be deleted. The *Nspecies* argument specifies
argument specifies how many species are eligible for deletion and is how many species are eligible for deletion and is followed by a list of
followed by a list of chemical formulae, whose strings are compared to chemical formulae, whose strings are compared to species identified by this
species identified by this fix. For example, "specieslist 2 CO CO2" fix. For example, "specieslist 2 CO CO2" deletes molecules that are
deletes molecules that are identified as "CO" and "CO2" in the species identified as "CO" and "CO2" in the species output file. When using the
output file. When using the *specieslist* keyword, the *filedel* file *specieslist* keyword, the *filedel* file has the following format: the
has the following format: the first line lists the chemical formulae first line lists the chemical formulae eligible for deletion, and each
eligible for deletion, and each additional line contains the timestep additional line contains the timestep on which a molecule deletion occurs
on which a molecule deletion occurs and the number of each species and the number of each species deleted on that timestep. The *masslimit*
deleted on that timestep. The *masslimit* keyword permits deletion of keyword permits deletion of molecules with molecular weights between
molecules with molecular weights between *massmin* and *massmax*. *massmin* and *massmax*. When using the *masslimit* keyword, each line of
When using the *masslimit* keyword, each line of the *filedel* file the *filedel* file contains the timestep on which deletions occurs,
contains the timestep on which deletions occurs, followed by how many followed by how many of each species are deleted (with quantities preceding
of each species are deleted (with quantities preceding chemical chemical formulae). The *specieslist* and *masslimit* keywords cannot both
formulae). The *specieslist* and *masslimit* keywords cannot both be be used in the same *reaxff/species* fix. The *delete_rate_limit* keyword
used in the same *reaxff/species* fix. The *delete_rate_limit* can enforce an upper limit on the overall rate of molecule deletion. The
keyword can enforce an upper limit on the overall rate of molecule number of deletion occurrences is limited to Nlimit within an interval of
deletion. The number of deletion occurrences is limited to Nlimit Nsteps timesteps. Nlimit can be specified with an equal-style
within an interval of Nsteps timesteps. Nlimit can be specified with :doc:`variable <variable>`. When using the *delete_rate_limit* keyword, no
an equal-style :doc:`variable <variable>`. When using the deletions are permitted to occur within the first Nsteps timesteps of the
*delete_rate_limit* keyword, no deletions are permitted to occur first run (after reading a either a data or restart file).
within the first Nsteps timesteps of the first run (after reading a
either a data or restart file).
---------- ----------
@ -233,5 +231,9 @@ Default
""""""" """""""
The default values for bond-order cutoffs are 0.3 for all I-J pairs. The default values for bond-order cutoffs are 0.3 for all I-J pairs.
The default element symbols are C, H, O, N. The default element symbols are taken from the ReaxFF pair_coeff command.
Position files are not written by default. Position files are not written by default.
.. _Delete:
**(Gissinger)** Jacob R. Gissinger, Scott R. Zavada, Joseph G. Smith, Josh Kemppainen, Ivan Gallegos, Gregory M. Odegard, Emilie J. Siochi, and Kristopher E. Wise, Carbon, 202, 336-347 (2023).

View File

@ -15,7 +15,7 @@ Syntax
* every_nsteps = number of MD steps between MC cycles * every_nsteps = number of MD steps between MC cycles
* swap_fraction = fraction of a full MC cycle carried out at each call (a value of 1.0 will perform as many trial moves as there are atoms) * swap_fraction = fraction of a full MC cycle carried out at each call (a value of 1.0 will perform as many trial moves as there are atoms)
* temperature = temperature that enters Boltzmann factor in Metropolis criterion (usually the same as MD temperature) * temperature = temperature that enters Boltzmann factor in Metropolis criterion (usually the same as MD temperature)
* deltamu = chemical potential difference(s) (`N-1` values must be provided, with `N` being the number of elements) * deltamu = `N-1` chemical potential differences :math:`\mu_1-\mu_2, \ldots, \mu_1-\mu_N` (`N` is the number of atom types)
* Zero or more keyword/value pairs may be appended to fix definition line: * Zero or more keyword/value pairs may be appended to fix definition line:
.. parsed-literal:: .. parsed-literal::
@ -23,7 +23,7 @@ Syntax
keyword = *variance* or *randseed* or *window_moves* or *window_size* keyword = *variance* or *randseed* or *window_moves* or *window_size*
*variance* kappa conc1 [conc2] ... [concN] *variance* kappa conc1 [conc2] ... [concN]
kappa = variance constraint parameter kappa = variance constraint parameter
conc1,conc2,... = target concentration(s) in the range 0.0-1.0 (*N-1* values must be provided, with *N* being the number of elements) `c_2`, `c_3`,..., `c_N` = `N-1` target concentration fractions
*randseed* N *randseed* N
N = seed for pseudo random number generator N = seed for pseudo random number generator
*window_moves* N *window_moves* N
@ -90,11 +90,10 @@ the simulation, e.g., to speed up equilibration at low temperatures.
------------ ------------
The parameter *deltamu* is used to set the chemical potential difference The parameter *deltamu* is used to set the chemical potential differences
in the SGC MC algorithm (see Eq. 16 in :ref:`Sadigh1 <Sadigh1>`). By in the SGC MC algorithm (see Eq. 16 in :ref:`Sadigh1 <Sadigh1>`).
convention it is the difference of the chemical potentials of elements The `N-1` differences are defined as :math:`\mu_1-\mu_2, \ldots, \mu_1-\mu_N`,
`B`, `C` ..., with respect to element A. When the simulation includes where `N` is the number of atom types.
`N` elements, `N-1` values must be specified.
------------ ------------
@ -104,12 +103,12 @@ the effective average constraint in the parallel VC-SGC MC algorithm
(parameter :math:`\delta\mu_0` in Eq. (20) of :ref:`Sadigh1 (parameter :math:`\delta\mu_0` in Eq. (20) of :ref:`Sadigh1
<Sadigh1>`). The parameter *kappa* specifies the variance constraint <Sadigh1>`). The parameter *kappa* specifies the variance constraint
(see Eqs. (20-21) in :ref:`Sadigh1 <Sadigh1>`). (see Eqs. (20-21) in :ref:`Sadigh1 <Sadigh1>`).
The parameter *conc* sets the `N-1` target atomic concentration
The parameter *conc* sets the target concentration (parameter fractions (parameter :math:`c_0` in Eqs. (20-21) of :ref:`Sadigh1 <Sadigh1>`)
:math:`c_0` in Eqs. (20-21) of :ref:`Sadigh1 <Sadigh1>`). The atomic :math:`0 \le c_2, \ldots, c_N \le 1`, with
concentrations refer to components `B`, `C` ..., with `A` being set :math:`c_1 = 1 - \Sigma_{i=2}^N c_i`.
automatically. When the simulation includes `N` elements, `N-1` When the simulation includes `N` atom types (elements),
concentration values must be specified. `N-1` concentration values must be specified.
------------ ------------
@ -143,10 +142,12 @@ components of the vector represent the following quantities:
* 1 = The absolute number of accepted trial swaps during the last MC step * 1 = The absolute number of accepted trial swaps during the last MC step
* 2 = The absolute number of rejected trial swaps during the last MC step * 2 = The absolute number of rejected trial swaps during the last MC step
* 3 = The current global concentration of species *A* (= number of atoms of type 1 / total number of atoms) * 3 = Current global concentration `c_1` (= number of atoms of type 1 / total number of atoms)
* 4 = The current global concentration of species *B* (= number of atoms of type 2 / total number of atoms) * 4 = Current global concentration `c_2` (= number of atoms of type 2 / total number of atoms)
* ... * ...
* N+2: The current global concentration of species *X* (= number of atoms of type *N* / total number of atoms) * N+2: Current global concentration `c_N` (= number of atoms of type *N* / total number of atoms)
The vector values calculated by this fix are "intensive".
Restrictions Restrictions
"""""""""""" """"""""""""

View File

@ -115,6 +115,18 @@ friction and twisting friction supported by the :doc:`pair_style granular <pair_
supported for walls. These are discussed in greater detail on the doc supported for walls. These are discussed in greater detail on the doc
page for :doc:`pair_style granular <pair_granular>`. page for :doc:`pair_style granular <pair_granular>`.
.. note::
When *fstyle* *granular* is specified, the associated *fstyle_params* are taken as
those for a wall/particle interaction. For example, for the *hertz/material* normal
contact model with :math:`E = 960` and :math:`\nu = 0.2`, the effective Young's
modulus for a wall/particle interaction is computed as
:math:`E_{eff} = \frac{960}{2(1-0.2^2)} = 500`. Any pair coefficients defined by
:doc:`pair_style granular <pair_granular>` are not taken into consideration. To
model different wall/particle interactions for particles of different material
types, the user may define multiple fix wall/gran commands operating on separate
groups (e.g. based on particle type) each with a different wall/particle effective
Young's modulus.
Note that you can choose a different force styles and/or different Note that you can choose a different force styles and/or different
values for the wall/particle coefficients than for particle/particle values for the wall/particle coefficients than for particle/particle
interactions. E.g. if you wish to model the wall as a different interactions. E.g. if you wish to model the wall as a different

View File

@ -14,7 +14,7 @@ Syntax
* widom = style name of this fix command * widom = style name of this fix command
* N = invoke this fix every N steps * N = invoke this fix every N steps
* M = number of Widom insertions to attempt every N steps * M = number of Widom insertions to attempt every N steps
* type = atom type for inserted atoms (must be 0 if mol keyword used) * type = atom type (1-Ntypes or type label) for inserted atoms (must be 0 if mol keyword used)
* seed = random # seed (positive integer) * seed = random # seed (positive integer)
* T = temperature of the system (temperature units) * T = temperature of the system (temperature units)
* zero or more keyword/value pairs may be appended to args * zero or more keyword/value pairs may be appended to args
@ -38,6 +38,9 @@ Examples
fix 2 gas widom 1 50000 1 19494 2.0 fix 2 gas widom 1 50000 1 19494 2.0
fix 3 water widom 1000 100 0 29494 300.0 mol h2omol full_energy fix 3 water widom 1000 100 0 29494 300.0 mol h2omol full_energy
labelmap atom 1 Li
fix 2 ion widom 1 50000 Li 19494 2.0
Description Description
""""""""""" """""""""""
@ -179,7 +182,7 @@ the following global cumulative quantities:
* 2 = average difference in potential energy on each timestep * 2 = average difference in potential energy on each timestep
* 3 = volume of the insertion region * 3 = volume of the insertion region
The vector values calculated by this fix are "extensive". The vector values calculated by this fix are "intensive".
No parameter of this fix can be used with the *start/stop* keywords of No parameter of this fix can be used with the *start/stop* keywords of
the :doc:`run <run>` command. This fix is not invoked during the :doc:`run <run>` command. This fix is not invoked during

View File

@ -20,13 +20,13 @@ Syntax
*empty* = no args *empty* = no args
*region* args = region-ID *region* args = region-ID
*type* or *id* or *molecule* *type* or *id* or *molecule*
args = list of one or more atom types, atom IDs, or molecule IDs args = list of one or more atom types (1-Ntypes or type label), atom IDs, or molecule IDs
any entry in list can be a sequence formatted as A:B or A:B:C where any numeric entry in list can be a sequence formatted as A:B or A:B:C where
A = starting index, B = ending index, A = starting index, B = ending index,
C = increment between indices, 1 if not specified C = increment between indices, 1 if not specified
args = logical value args = logical value
logical = "<" or "<=" or ">" or ">=" or "==" or "!=" logical = "<" or "<=" or ">" or ">=" or "==" or "!="
value = an atom type or atom ID or molecule ID (depending on *style*\ ) value = an atom type (1-Ntypes or type label) or atom ID or molecule ID (depending on *style*\ )
args = logical value1 value2 args = logical value1 value2
logical = "<>" logical = "<>"
value1,value2 = atom types or atom IDs or molecule IDs (depending on *style*\ ) value1,value2 = atom types or atom IDs or molecule IDs (depending on *style*\ )
@ -52,6 +52,7 @@ Examples
group edge region regstrip group edge region regstrip
group water type 3 4 group water type 3 4
group water type OW HT
group sub id 10 25 50 group sub id 10 25 50
group sub id 10 25 50 500:1000 group sub id 10 25 50 500:1000
group sub id 100:10000:10 group sub id 100:10000:10
@ -119,7 +120,7 @@ three styles can use arguments specified in one of two formats.
The first format is a list of values (types or IDs). For example, the The first format is a list of values (types or IDs). For example, the
second command in the examples above puts all atoms of type 3 or 4 into second command in the examples above puts all atoms of type 3 or 4 into
the group named *water*\ . Each entry in the list can be a the group named *water*\ . Each numeric entry in the list can be a
colon-separated sequence ``A:B`` or ``A:B:C``, as in two of the examples colon-separated sequence ``A:B`` or ``A:B:C``, as in two of the examples
above. A "sequence" generates a sequence of values (types or IDs), above. A "sequence" generates a sequence of values (types or IDs),
with an optional increment. The first example with ``500:1000`` has the with an optional increment. The first example with ``500:1000`` has the
@ -135,7 +136,8 @@ except ``<>`` take a single argument. The third example above adds all
atoms with IDs from 1 to 150 to the group named *sub*\ . The logical ``<>`` atoms with IDs from 1 to 150 to the group named *sub*\ . The logical ``<>``
means "between" and takes 2 arguments. The fourth example above adds all means "between" and takes 2 arguments. The fourth example above adds all
atoms belonging to molecules with IDs from 50 to 250 (inclusive) to atoms belonging to molecules with IDs from 50 to 250 (inclusive) to
the group named polyA. the group named polyA. For the *type* style, type labels are converted into
numeric types before being evaluated.
The *variable* style evaluates a variable to determine which atoms to The *variable* style evaluates a variable to determine which atoms to
add to the group. It must be an :doc:`atom-style variable <variable>` add to the group. It must be an :doc:`atom-style variable <variable>`

View File

@ -34,32 +34,66 @@ Description
Write or read a Gromacs style index file in text format that associates Write or read a Gromacs style index file in text format that associates
atom IDs with the corresponding group definitions. This index file can be atom IDs with the corresponding group definitions. This index file can be
used with in combination with Gromacs analysis tools or to import group used with in combination with Gromacs analysis tools or to import group
definitions into the :doc:`fix colvars <fix_colvars>` input file. It can definitions into the :doc:`fix colvars <fix_colvars>` input file.
also be used to save and restore group definitions for static groups.
It can also be used to save and restore group definitions for static groups
using the individual atom IDs. This may be important if the original
group definition depends on a region or otherwise on the geometry and thus
cannot be easily recreated.
Another application would be to import atom groups defined for Gromacs
simulation into LAMMPS. When translating Gromacs topology and geometry
data to LAMMPS.
The *group2ndx* command will write group definitions to an index file. The *group2ndx* command will write group definitions to an index file.
Without specifying any group IDs, all groups will be written to the index Without specifying any group IDs, all groups will be written to the
file. When specifying group IDs, only those groups will be written to the index file. When specifying group IDs, only those groups will be
index file. In order to follow the Gromacs conventions, the group *all* written to the index file. In order to follow the Gromacs conventions,
will be renamed to *System* in the index file. the group *all* will be renamed to *System* in the index file.
The *ndx2group* command will create of update group definitions from those The *ndx2group* command will create of update group definitions from
stored in an index file. Without specifying any group IDs, all groups except those stored in an index file. Without specifying any group IDs, all
*System* will be read from the index file and the corresponding groups groups except *System* will be read from the index file and the
recreated. If a group of the same name already exists, it will be completely corresponding groups recreated. If a group of the same name already
reset. When specifying group IDs, those groups, if present, will be read exists, it will be completely reset. When specifying group IDs, those
from the index file and restored. groups, if present, will be read from the index file and restored.
File Format
"""""""""""
The file format is equivalent and compatible with what is produced by
the `Gromacs make_ndx command <https://manual.gromacs.org/current/onlinehelp/gmx-make_ndx.html>`_.
and follows the `Gromacs definition of an ndx file <https://manual.gromacs.org/current/reference-manual/file-formats.html#ndx>`_
Each group definition begins with the group name in square brackets with
blanks, e.g. \[ water \] and is then followed by the list of atom
indices, which may be spread over multiple lines. Here is a small
example file:
.. code-block:: ini
[ Oxygen ]
1 4 7
[ Hydrogen ]
2 3 5 6
8 9
[ Water ]
1 2 3 4 5 6 7 8 9
The index file defines 3 groups: Oxygen, Hydrogen, and Water and the
latter happens to be the union of the first two.
---------- ----------
Restrictions Restrictions
"""""""""""" """"""""""""
This command requires that atoms have atom IDs, since this is the These commands require that atoms have atom IDs, since this is the
information that is written to the index file. information that is written to the index file.
These commands are part of the COLVARS package. They are only These commands are part of the EXTRA-COMMAND package. They are only
enabled if LAMMPS was built with that package. See the :doc:`Build package <Build_package>` page for more info. enabled if LAMMPS was built with that package. See the
:doc:`Build package <Build_package>` page for more info.
Related commands Related commands
"""""""""""""""" """"""""""""""""

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@ -64,8 +64,8 @@ Restrictions
"""""""""""" """"""""""""
This improper style can only be used if LAMMPS was built with the This improper style can only be used if LAMMPS was built with the
MOLECULE package. See the :doc:`Build package <Build_package>` doc EXTRA-MOLECULE package. See the :doc:`Build package <Build_package>`
page for more info. doc page for more info.
Related commands Related commands
"""""""""""""""" """"""""""""""""

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@ -54,8 +54,8 @@ Restrictions
"""""""""""" """"""""""""
This improper style can only be used if LAMMPS was built with the This improper style can only be used if LAMMPS was built with the
MOLECULE package. See the :doc:`Build package <Build_package>` doc EXTRA-MOLECULE package. See the :doc:`Build package <Build_package>`
page for more info. doc page for more info.
Related commands Related commands
"""""""""""""""" """"""""""""""""

View File

@ -60,8 +60,8 @@ Restrictions
"""""""""""" """"""""""""
This angle style can only be used if LAMMPS was built with the This angle style can only be used if LAMMPS was built with the
MOLECULE package. See the :doc:`Build package <Build_package>` doc EXTRA-MOLECULE package. See the :doc:`Build package <Build_package>`
page for more info. doc page for more info.
Related commands Related commands
"""""""""""""""" """"""""""""""""

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@ -72,8 +72,8 @@ Restrictions
"""""""""""" """"""""""""
This improper style can only be used if LAMMPS was built with the This improper style can only be used if LAMMPS was built with the
MOLECULE package. See the :doc:`Build package <Build_package>` doc EXTRA-MOLECULE package. See the :doc:`Build package <Build_package>`
page for more info. doc page for more info.
Related commands Related commands
"""""""""""""""" """"""""""""""""

View File

@ -24,6 +24,7 @@ Examples
.. code-block:: LAMMPS .. code-block:: LAMMPS
labelmap atom 1 c1 2 hc 3 cp 4 nt
labelmap atom 3 carbon 4 'c3"' 5 "c1'" 6 "c#" labelmap atom 3 carbon 4 'c3"' 5 "c1'" 6 "c#"
labelmap atom $(label2type(atom,carbon)) C # change type label from 'carbon' to 'C' labelmap atom $(label2type(atom,carbon)) C # change type label from 'carbon' to 'C'
labelmap clear labelmap clear
@ -43,8 +44,8 @@ The label map can also be defined by the :doc:`read_data <read_data>`
command when it reads these sections in a data file: Atom Type Labels, command when it reads these sections in a data file: Atom Type Labels,
Bond Type Labels, etc. See the :doc:`Howto type labels Bond Type Labels, etc. See the :doc:`Howto type labels
<Howto_type_labels>` doc page for a general discussion of how type <Howto_type_labels>` doc page for a general discussion of how type
labels can be used. See :ref:`(Gissinger) <Typelabel>` for a discussion labels can be used. See :ref:`(Gissinger) <Typelabel1>` for a
of the type label implementation in LAMMPS and its uses. discussion of the type label implementation in LAMMPS and its uses.
Valid type labels can contain any alphanumeric character, but must not Valid type labels can contain any alphanumeric character, but must not
start with a number, a '#', or a '*' character. They can contain other start with a number, a '#', or a '*' character. They can contain other
@ -102,6 +103,6 @@ none
----------- -----------
.. _Typelabel: .. _Typelabel1:
**(Gissinger)** J. R. Gissinger, I. Nikiforov, Y. Afshar, B. Waters, M. Choi, D. S. Karls, A. Stukowski, W. Im, H. Heinz, A. Kohlmeyer, and E. B. Tadmor, J Phys Chem B, 128, 3282-3297 (2024). **(Gissinger)** J. R. Gissinger, I. Nikiforov, Y. Afshar, B. Waters, M. Choi, D. S. Karls, A. Stukowski, W. Im, H. Heinz, A. Kohlmeyer, and E. B. Tadmor, J Phys Chem B, 128, 3282-3297 (2024).

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@ -112,26 +112,22 @@ Description
These pair styles compute Lennard Jones (LJ) and Coulombic These pair styles compute Lennard Jones (LJ) and Coulombic
interactions with additional switching or shifting functions that ramp interactions with additional switching or shifting functions that ramp
the energy and/or force smoothly to zero between an inner and outer the energy and/or force smoothly to zero between an inner and outer
cutoff. They are implementations of the widely used CHARMM force cutoff. They implement the widely used CHARMM force field, see
field used in the `CHARMM <https://www.charmm.org>`_ MD code (and :doc:`Howto discussion on biomolecular force fields <Howto_bioFF>` for
others). See :ref:`(MacKerell) <pair-MacKerell>` for a description of the details.
CHARMM force field.
The styles with *charmm* (not *charmmfsw* or *charmmfsh*\ ) in their The styles with *charmm* (not *charmmfsw* or *charmmfsh*\ ) in their
name are the older, original LAMMPS implementations. They compute the name are the older, original LAMMPS implementations. They compute the
LJ and Coulombic interactions with an energy switching function (esw, LJ and Coulombic interactions with an energy switching function which
shown in the formula below as S(r)), which ramps the energy smoothly ramps the energy smoothly to zero between the inner and outer cutoff.
to zero between the inner and outer cutoff. This can cause This can cause irregularities in pairwise forces (due to the discontinuous
irregularities in pairwise forces (due to the discontinuous second second derivative of energy at the boundaries of the switching region),
derivative of energy at the boundaries of the switching region), which which in some cases can result in detectable artifacts in an MD simulation.
in some cases can result in detectable artifacts in an MD simulation.
The newer styles with *charmmfsw* or *charmmfsh* in their name replace The newer styles with *charmmfsw* or *charmmfsh* in their name replace
the energy switching with force switching (fsw) and force shifting the energy switching with force switching (fsw) and force shifting
(fsh) functions, for LJ and Coulombic interactions respectively. (fsh) functions, for LJ and Coulombic interactions respectively.
These follow the formulas and description given in
:ref:`(Steinbach) <Steinbach>` and :ref:`(Brooks) <Brooks1>` to minimize these
artifacts.
.. note:: .. note::
@ -152,26 +148,6 @@ artifacts.
the CHARMM force field energies and forces, when using one of these the CHARMM force field energies and forces, when using one of these
two CHARMM pair styles. two CHARMM pair styles.
.. math::
E = & LJ(r) \qquad \qquad \qquad r < r_{\rm in} \\
= & S(r) * LJ(r) \qquad \qquad r_{\rm in} < r < r_{\rm out} \\
= & 0 \qquad \qquad \qquad \qquad r > r_{\rm out} \\
E = & C(r) \qquad \qquad \qquad r < r_{\rm in} \\
= & S(r) * C(r) \qquad \qquad r_{\rm in} < r < r_{\rm out} \\
= & 0 \qquad \qquad \qquad \qquad r > r_{\rm out} \\
LJ(r) = & 4 \epsilon \left[ \left(\frac{\sigma}{r}\right)^{12} -
\left(\frac{\sigma}{r}\right)^6 \right] \\
C(r) = & \frac{C q_i q_j}{ \epsilon r} \\
S(r) = & \frac{ \left[r_{\rm out}^2 - r^2\right]^2
\left[r_{\rm out}^2 + 2r^2 - 3{r_{\rm in}^2}\right]}
{ \left[r_{\rm out}^2 - {r_{\rm in}}^2\right]^3 }
where S(r) is the energy switching function mentioned above for the
*charmm* styles. See the :ref:`(Steinbach) <Steinbach>` paper for the
functional forms of the force switching and force shifting functions
used in the *charmmfsw* and *charmmfsh* styles.
When using the *lj/charmm/coul/charmm styles*, both the LJ and When using the *lj/charmm/coul/charmm styles*, both the LJ and
Coulombic terms require an inner and outer cutoff. They can be the Coulombic terms require an inner and outer cutoff. They can be the
same for both formulas or different depending on whether 2 or 4 same for both formulas or different depending on whether 2 or 4

View File

@ -379,10 +379,11 @@ These pair styles can only be used via the *pair* keyword of the
Restrictions Restrictions
"""""""""""" """"""""""""
The *coul/cut/global*, *coul/long*, *coul/msm*, *coul/streitz*, and *tip4p/long* styles The *coul/long*, *coul/msm*, *coul/streitz*, and *tip4p/long* styles are
are part of the KSPACE package. They are only enabled if LAMMPS was built part of the KSPACE package. The *coul/cut/global* and *coul/exclude* are
with that package. See the :doc:`Build package <Build_package>` doc page part of the EXTRA-PAIR package. A pair style is only enabled if LAMMPS was
for more info. built with its corresponding package. See the :doc:`Build package <Build_package>`
doc page for more info.
Related commands Related commands
"""""""""""""""" """"""""""""""""

View File

@ -0,0 +1,196 @@
.. index:: pair_style dpd/coul/slater/long
.. index:: pair_style dpd/coul/slater/long/gpu
pair_style dpd/coul/slater/long command
=======================================
Accelerator Variants: *dpd/coul/slater/long/gpu*
Syntax
""""""
.. code-block:: LAMMPS
pair_style dpd/coul/slater/long T cutoff_DPD seed lambda cutoff_coul
* T = temperature (temperature units)
* cutoff_DPD = global cutoff for DPD interactions (distance units)
* seed = random # seed (positive integer)
* lambda = decay length of the charge (distance units)
* cutoff_coul = global cutoff for Coulombic interactions (distance units)
Examples
""""""""
.. code-block:: LAMMPS
pair_style dpd/coul/slater/long 1.0 2.5 34387 0.25 3.0
pair_coeff 1 1 78.0 4.5 # not charged by default
pair_coeff 2 2 78.0 4.5 yes
Description
"""""""""""
.. versionadded:: 27June2024
Style *dpd/coul/slater/long* computes a force field for dissipative
particle dynamics (DPD) following the exposition in :ref:`(Groot)
<Groot5>`. It also allows for the use of charged particles in the
model by adding a long-range Coulombic term to the DPD interactions.
The short-range portion of the Coulombics is calculated by this pair
style. The long-range Coulombics are computed by use of the
:doc:`kspace_style <kspace_style>` command, e.g. using the Ewald or
PPPM styles.
Coulombic forces in mesoscopic models such as DPD employ potentials
without explicit excluded-volume interactions. The goal is to prevent
artificial ionic pair formation by including a charge distribution in
the Coulomb potential, following the formulation in :ref:`(Melchor1)
<Melchor1>`.
.. note::
This pair style is effectively the combination of the
:doc:`pair_style dpd <pair_dpd>` and :doc:`pair_style
coul/slater/long <pair_coul_slater>` commands, but should be more
efficient (especially on GPUs) than using :doc:`pair_style
hybrid/overlay dpd coul/slater/long <pair_hybrid>`. That is
particularly true for the GPU package version of the pair style since
this version is compatible with computing neighbor lists on the GPU
instead of the CPU as is required for hybrid styles.
In the charged DPD model, the force on bead I due to bead J is given
as a sum of 4 terms:
.. math::
\vec{f} = & (F^C + F^D + F^R + F^E) \hat{r_{ij}} \\
F^C = & A w(r) \qquad \qquad \qquad \qquad \qquad r < r_{DPD} \\
F^D = & - \gamma w^2(r) (\hat{r_{ij}} \bullet \vec{v}_{ij}) \qquad \qquad r < r_{DPD} \\
F^R = & \sigma w(r) \alpha (\Delta t)^{-1/2} \qquad \qquad \qquad r < r_{DPD} \\
w(r) = & 1 - \frac{r}{r_{DPD}} \\
F^E = & \frac{C q_iq_j}{\epsilon r^2} \left( 1- exp\left( \frac{2r_{ij}}{\lambda} \right) \left( 1 + \frac{2r_{ij}}{\lambda} \left( 1 + \frac{r_{ij}}{\lambda} \right)\right) \right)
where :math:`F^C` is a conservative force, :math:`F^D` is a
dissipative force, :math:`F^R` is a random force, and :math:`F^E` is
an electrostatic force. :math:`\hat{r_{ij}}` is a unit vector in the
direction :math:`r_i - r_j`, :math:`\vec{v}_{ij}` is the vector
difference in velocities of the two atoms :math:`\vec{v}_i -
\vec{v}_j`, :math:`\alpha` is a Gaussian random number with zero mean
and unit variance, *dt* is the timestep size, and :math:`w(r)` is a
weighting factor that varies between 0 and 1.
:math:`\sigma` is set equal to :math:`\sqrt{2 k_B T \gamma}`, where
:math:`k_B` is the Boltzmann constant and *T* is the temperature
parameter in the pair_style command.
:math:`r_{DPD}` is the pairwise cutoff for the first 3 DPD terms in
the formula as specified by *cutoff_DPD*. For the :math:`F^E` term,
pairwise interactions within the specified *cutoff_coul* distance are
computed directly; interactions beyond that distance are computed in
reciprocal space. *C* is the same Coulomb conversion factor used in
the Coulombic formulas described on the :doc:`pair_coul <pair_coul>`
doc page.
The following parameters must be defined for each pair of atoms types
via the :doc:`pair_coeff <pair_coeff>` command as in the examples
above, or in the data file or restart files read by the
:doc:`read_data <read_data>` or :doc:`read_restart <read_restart>`
commands:
* A (force units)
* :math:`\gamma` (force/velocity units)
* is_charged (optional boolean, default = no)
The *is_charged* parameter is optional and can be specified as *yes* or
*no*. *Yes* should be used for interactions between two types of
charged particles. *No* is the default and should be used for
interactions between two types of particles when one or both are
uncharged.
----------
.. include:: accel_styles.rst
----------
Mixing, shift, table, tail correction, restart, rRESPA info
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
This pair style does not support mixing. Thus, coefficients for all
I,J pairs must be specified explicitly.
This pair style does not support the :doc:`pair_modify <pair_modify>`
shift option for the energy of the pair interaction.
The :doc:`pair_modify <pair_modify>` table option is not relevant
for this pair style.
This pair style does not support the :doc:`pair_modify <pair_modify>`
tail option for adding long-range tail corrections to energy and
pressure.
This pair style writes its information to :doc:`binary restart files
<restart>`, so pair_style and pair_coeff commands do not need to be
specified in an input script that reads a restart file. Note that the
user-specified random number seed is stored in the restart file, so
when a simulation is restarted, each processor will re-initialize its
random number generator the same way it did initially. This means the
random forces will be random, but will not be the same as they would
have been if the original simulation had continued past the restart
time.
This pair style can only be used via the *pair* keyword of the
:doc:`run_style respa <run_style>` command. It does not support the
*inner*, *middle*, *outer* keywords.
----------
Restrictions
""""""""""""
This style is part of the DPD-BASIC package. It is only enabled if
LAMMPS was built with that package. See the :doc:`Build package
<Build_package>` page for more info.
The default frequency for rebuilding neighbor lists is every 10 steps
(see the :doc:`neigh_modify <neigh_modify>` command). This may be too
infrequent since particles move rapidly and can overlap by large
amounts. If this setting yields a non-zero number of "dangerous"
reneighborings (printed at the end of a simulation), you should
experiment with forcing reneighboring more often and see if system
energies/trajectories change.
This pair style requires use of the :doc:`comm_modify vel yes
<comm_modify>` command so that velocities are stored by ghost atoms.
This pair style also requires use of a long-range solvers from the
KSPACE package.
This pair style will not restart exactly when using the
:doc:`read_restart <read_restart>` command, though they should provide
statistically similar results. This is because the forces they compute
depend on atom velocities. See the :doc:`read_restart <read_restart>`
command for more details.
Related commands
""""""""""""""""
:doc:`pair_style dpd <pair_dpd>`, :doc:`pair_style coul/slater/long <pair_coul_slater>`,
Default
"""""""
For the pair_coeff command, the default is is_charged = no.
----------
.. _Groot5:
**(Groot)** Groot and Warren, J Chem Phys, 107, 4423-35 (1997).
.. _Melchor1:
**(Melchor)** Gonzalez-Melchor, Mayoral, Velazquez, and Alejandre, J Chem Phys, 125, 224107 (2006).

View File

@ -111,7 +111,7 @@ For the *hertz* model, the normal component of force is given by:
\mathbf{F}_{ne, Hertz} = k_n R_{eff}^{1/2}\delta_{ij}^{3/2} \mathbf{n} \mathbf{F}_{ne, Hertz} = k_n R_{eff}^{1/2}\delta_{ij}^{3/2} \mathbf{n}
Here, :math:`R_{eff} = \frac{R_i R_j}{R_i + R_j}` is the effective Here, :math:`R_{eff} = R = \frac{R_i R_j}{R_i + R_j}` is the effective
radius, denoted for simplicity as *R* from here on. For *hertz*, the radius, denoted for simplicity as *R* from here on. For *hertz*, the
units of the spring constant :math:`k_n` are *force*\ /\ *length*\ \^2, or units of the spring constant :math:`k_n` are *force*\ /\ *length*\ \^2, or
equivalently *pressure*\ . equivalently *pressure*\ .
@ -120,13 +120,14 @@ For the *hertz/material* model, the force is given by:
.. math:: .. math::
\mathbf{F}_{ne, Hertz/material} = \frac{4}{3} E_{eff} R_{eff}^{1/2}\delta_{ij}^{3/2} \mathbf{n} \mathbf{F}_{ne, Hertz/material} = \frac{4}{3} E_{eff} R^{1/2}\delta_{ij}^{3/2} \mathbf{n}
Here, :math:`E_{eff} = E = \left(\frac{1-\nu_i^2}{E_i} + \frac{1-\nu_j^2}{E_j}\right)^{-1}` is the effective Young's Here, :math:`E_{eff} = E = \left(\frac{1-\nu_i^2}{E_i} + \frac{1-\nu_j^2}{E_j}\right)^{-1}`
modulus, with :math:`\nu_i, \nu_j` the Poisson ratios of the particles of is the effective Young's modulus, with :math:`\nu_i, \nu_j` the Poisson ratios
types *i* and *j*\ . Note that if the elastic modulus and the shear of the particles of types *i* and *j*. :math:`E_{eff}` is denoted as *E* from here on.
modulus of the two particles are the same, the *hertz/material* model Note that if the elastic modulus and the shear modulus of the two particles are the
is equivalent to the *hertz* model with :math:`k_n = 4/3 E_{eff}` same, the *hertz/material* model is equivalent to the *hertz* model with
:math:`k_n = 4/3 E`
The *dmt* model corresponds to the The *dmt* model corresponds to the
:ref:`(Derjaguin-Muller-Toporov) <DMT1975>` cohesive model, where the force :ref:`(Derjaguin-Muller-Toporov) <DMT1975>` cohesive model, where the force
@ -187,6 +188,7 @@ for the damping model currently supported are:
2. *mass_velocity* 2. *mass_velocity*
3. *viscoelastic* 3. *viscoelastic*
4. *tsuji* 4. *tsuji*
5. *coeff_restitution*
If the *damping* keyword is not specified, the *viscoelastic* model is If the *damping* keyword is not specified, the *viscoelastic* model is
used by default. used by default.
@ -248,6 +250,30 @@ The dimensionless coefficient of restitution :math:`e` specified as part
of the normal contact model parameters should be between 0 and 1, but of the normal contact model parameters should be between 0 and 1, but
no error check is performed on this. no error check is performed on this.
The *coeff_restitution* model is useful when a specific normal coefficient of
restitution :math:`e` is required. In these models, the normal coefficient of
restitution :math:`e` is specified as an input. Following the approach of
:ref:`(Brilliantov et al) <Brill1996>`, when using the *hooke* normal model,
*coeff_restitution* calculates the damping coefficient as:
.. math::
\eta_n = \sqrt{\frac{4m_{eff}k_n}{1+\left( \frac{\pi}{\log(e)}\right)^2}} ,
For any other normal model, e.g. the *hertz* and *hertz/material* models, the damping
coefficient is:
.. math::
\eta_n = -2\sqrt{\frac{5}{6}}\frac{\log(e)}{\sqrt{\pi^2+(\log(e))^2}}(R_{eff} \delta_{ij})^{\frac{1}{4}}\sqrt{\frac{3}{2}k_n m_{eff}} ,
where :math:`k_n = \frac{4}{3} E_{eff}` for the *hertz/material* model. Since
*coeff_restitution* accounts for the effective mass, effective radius, and
pairwise overlaps (except when used with the *hooke* normal model) when calculating
the damping coefficient, it accurately reproduces the specified coefficient of
restitution for both monodisperse and polydisperse particle pairs. This damping
model is not compatible with cohesive normal models such as *JKR* or *DMT*.
The total normal force is computed as the sum of the elastic and The total normal force is computed as the sum of the elastic and
damping components: damping components:
@ -417,11 +443,11 @@ discussion above. To match the Mindlin solution, one should set
G_{eff} = \left(\frac{2-\nu_i}{G_i} + \frac{2-\nu_j}{G_j}\right)^{-1} G_{eff} = \left(\frac{2-\nu_i}{G_i} + \frac{2-\nu_j}{G_j}\right)^{-1}
where :math:`G` is the shear modulus, related to Young's modulus :math:`E` where :math:`G_i` is the shear modulus of a particle of type :math:`i`, related to Young's
and Poisson's ratio :math:`\nu` by :math:`G = E/(2(1+\nu))`. This can also be modulus :math:`E_i` and Poisson's ratio :math:`\nu_i` by :math:`G_i = E_i/(2(1+\nu_i))`.
achieved by specifying *NULL* for :math:`k_t`, in which case a This can also be achieved by specifying *NULL* for :math:`k_t`, in which case a
normal contact model that specifies material parameters :math:`E` and normal contact model that specifies material parameters :math:`E_i` and
:math:`\nu` is required (e.g. *hertz/material*, *dmt* or *jkr*\ ). In this :math:`\nu_i` is required (e.g. *hertz/material*, *dmt* or *jkr*\ ). In this
case, mixing of the shear modulus for different particle types *i* and case, mixing of the shear modulus for different particle types *i* and
*j* is done according to the formula above. *j* is done according to the formula above.
@ -551,7 +577,7 @@ opposite torque on each particle, according to:
.. math:: .. math::
\tau_{roll,i} = R_{eff} \mathbf{n} \times \mathbf{F}_{roll} \tau_{roll,i} = R \mathbf{n} \times \mathbf{F}_{roll}
.. math:: .. math::

View File

@ -1,28 +1,41 @@
.. index:: pair_style hybrid .. index:: pair_style hybrid
.. index:: pair_style hybrid/kk .. index:: pair_style hybrid/kk
.. index:: pair_style hybrid/omp
.. index:: pair_style hybrid/molecular
.. index:: pair_style hybrid/molecular/omp
.. index:: pair_style hybrid/overlay .. index:: pair_style hybrid/overlay
.. index:: pair_style hybrid/overlay/omp
.. index:: pair_style hybrid/overlay/kk .. index:: pair_style hybrid/overlay/kk
.. index:: pair_style hybrid/scaled .. index:: pair_style hybrid/scaled
.. index:: pair_style hybrid/scaled/omp
pair_style hybrid command pair_style hybrid command
========================= =========================
Accelerator Variants: *hybrid/kk* Accelerator Variants: *hybrid/kk*, *hybrid/omp*
pair_style hybrid/molecular command
===================================
Accelerator Variant: *hybrid/molecular/omp*
pair_style hybrid/overlay command pair_style hybrid/overlay command
================================= =================================
Accelerator Variants: *hybrid/overlay/kk* Accelerator Variants: *hybrid/overlay/kk*, *hybrid/overlay/omp*
pair_style hybrid/scaled command pair_style hybrid/scaled command
================================== ==================================
Accelerator Variant: *hybrid/scaled/omp*
Syntax Syntax
"""""" """"""
.. code-block:: LAMMPS .. code-block:: LAMMPS
pair_style hybrid style1 args style2 args ... pair_style hybrid style1 args style2 args ...
pair_style hybrid/molecular factor1 style1 args factor2 style 2 args
pair_style hybrid/overlay style1 args style2 args ... pair_style hybrid/overlay style1 args style2 args ...
pair_style hybrid/scaled factor1 style1 args factor2 style 2 args ... pair_style hybrid/scaled factor1 style1 args factor2 style 2 args ...
@ -47,6 +60,10 @@ Examples
pair_coeff * * tersoff Si.tersoff Si pair_coeff * * tersoff Si.tersoff Si
pair_coeff * * sw Si.sw Si pair_coeff * * sw Si.sw Si
pair_style hybrid/molecular lj/cut 2.5 lj/cut 2.5
pair_coeff * * lj/cut 1 1.0 1.0
pair_coeff * * lj/cut 2 1.5 1.0
variable one equal ramp(1.0,0.0) variable one equal ramp(1.0,0.0)
variable two equal 1.0-v_one variable two equal 1.0-v_one
pair_style hybrid/scaled v_one lj/cut 2.5 v_two morse 2.5 pair_style hybrid/scaled v_one lj/cut 2.5 v_two morse 2.5
@ -56,17 +73,26 @@ Examples
Description Description
""""""""""" """""""""""
The *hybrid*, *hybrid/overlay*, and *hybrid/scaled* styles enable the The *hybrid*, *hybrid/overlay*, *hybrid/molecular*, and *hybrid/scaled*
use of multiple pair styles in one simulation. With the *hybrid* style, styles enable the use of multiple pair styles in one simulation. With
exactly one pair style is assigned to each pair of atom types. With the the *hybrid* style, exactly one pair style is assigned to each pair of
*hybrid/overlay* and *hybrid/scaled* styles, one or more pair styles can atom types. With the *hybrid/overlay* and *hybrid/scaled* styles, one
be assigned to each pair of atom types. The assignment of pair styles or more pair styles can be assigned to each pair of atom types. With
to type pairs is made via the :doc:`pair_coeff <pair_coeff>` command. the hybrid/molecular style, pair styles are assigned to either intra-
The major difference between the *hybrid/overlay* and *hybrid/scaled* or inter-molecular interactions.
styles is that the *hybrid/scaled* adds a scale factor for each
sub-style contribution to forces, energies and stresses. Because of the The assignment of pair styles to type pairs is made via the
added complexity, the *hybrid/scaled* style has more overhead and thus :doc:`pair_coeff <pair_coeff>` command. The major difference between
may be slower than *hybrid/overlay*. the *hybrid/overlay* and *hybrid/scaled* styles is that the
*hybrid/scaled* adds a scale factor for each sub-style contribution to
forces, energies and stresses. Because of the added complexity, the
*hybrid/scaled* style has more overhead and thus may be slower than
*hybrid/overlay*.
The *hybrid/molecular* pair style accepts *only* two sub-styles: the
first is assigned to intra-molecular interactions (i.e. both atoms
have the same molecule ID), the second to inter-molecular interactions
(i.e. interacting atoms have different molecule IDs).
Here are two examples of hybrid simulations. The *hybrid* style could Here are two examples of hybrid simulations. The *hybrid* style could
be used for a simulation of a metal droplet on a LJ surface. The metal be used for a simulation of a metal droplet on a LJ surface. The metal
@ -476,6 +502,8 @@ the same or else LAMMPS will generate an error.
Pair style *hybrid/scaled* currently only works for non-accelerated Pair style *hybrid/scaled* currently only works for non-accelerated
pair styles and pair styles from the OPT package. pair styles and pair styles from the OPT package.
Pair style *hybrid/molecular* is not compatible with manybody potentials.
When using pair styles from the GPU package they must not be listed When using pair styles from the GPU package they must not be listed
multiple times. LAMMPS will detect this and abort. multiple times. LAMMPS will detect this and abort.

View File

@ -37,18 +37,19 @@ Syntax
*oxdna/stk* args = seq T xi kappa 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65 *oxdna/stk* args = seq T xi kappa 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65
seq = seqav (for average sequence stacking strength) or seqdep (for sequence-dependent stacking strength) seq = seqav (for average sequence stacking strength) or seqdep (for sequence-dependent stacking strength)
T = temperature (oxDNA units, 0.1 = 300 K) T = temperature (LJ units: 0.1 = 300 K, real units: 300 = 300 K)
xi = 1.3448 (temperature-independent coefficient in stacking strength) xi = 1.3448 (LJ units) or 8.01727944817084 (real units), temperature-independent coefficient in stacking strength
kappa = 2.6568 (coefficient of linear temperature dependence in stacking strength) kappa = 2.6568 (LJ units) or 0.005279604 (real units), coefficient of linear temperature dependence in stacking strength
*oxdna/hbond* args = seq eps 8.0 0.4 0.75 0.34 0.7 1.5 0 0.7 1.5 0 0.7 1.5 0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45 *oxdna/hbond* args = seq eps 8.0 0.4 0.75 0.34 0.7 1.5 0 0.7 1.5 0 0.7 1.5 0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
seq = seqav (for average sequence base-pairing strength) or seqdep (for sequence-dependent base-pairing strength) seq = seqav (for average sequence base-pairing strength) or seqdep (for sequence-dependent base-pairing strength)
eps = 1.077 (between base pairs A-T and C-G) or 0 (all other pairs) eps = 1.077 (LJ units) or 6.42073911784652 (real units), average hydrogen bonding strength between A-T and C-G Watson-Crick base pairs, 0 between all other pairs
Examples Examples
"""""""" """"""""
.. code-block:: LAMMPS .. code-block:: LAMMPS
# LJ units
pair_style hybrid/overlay oxdna/excv oxdna/stk oxdna/hbond oxdna/xstk oxdna/coaxstk pair_style hybrid/overlay oxdna/excv oxdna/stk oxdna/hbond oxdna/xstk oxdna/coaxstk
pair_coeff * * oxdna/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32 pair_coeff * * oxdna/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32
pair_coeff * * oxdna/stk seqdep 0.1 1.3448 2.6568 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65 pair_coeff * * oxdna/stk seqdep 0.1 1.3448 2.6568 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65
@ -58,55 +59,105 @@ Examples
pair_coeff * * oxdna/xstk 47.5 0.575 0.675 0.495 0.655 2.25 0.791592653589793 0.58 1.7 1.0 0.68 1.7 1.0 0.68 1.5 0 0.65 1.7 0.875 0.68 1.7 0.875 0.68 pair_coeff * * oxdna/xstk 47.5 0.575 0.675 0.495 0.655 2.25 0.791592653589793 0.58 1.7 1.0 0.68 1.7 1.0 0.68 1.5 0 0.65 1.7 0.875 0.68 1.7 0.875 0.68
pair_coeff * * oxdna/coaxstk 46.0 0.4 0.6 0.22 0.58 2.0 2.541592653589793 0.65 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 -0.65 2.0 -0.65 pair_coeff * * oxdna/coaxstk 46.0 0.4 0.6 0.22 0.58 2.0 2.541592653589793 0.65 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 -0.65 2.0 -0.65
pair_style hybrid/overlay oxdna/excv oxdna/stk oxdna/hbond oxdna/xstk oxdna/coaxstk
pair_coeff * * oxdna/excv oxdna_lj.cgdna
pair_coeff * * oxdna/stk seqav 0.1 1.3448 2.6568 oxdna_lj.cgdna
pair_coeff * * oxdna/hbond seqav oxdna_lj.cgdna
pair_coeff 1 4 oxdna/hbond seqav oxdna_lj.cgdna
pair_coeff 2 3 oxdna/hbond seqav oxdna_lj.cgdna
pair_coeff * * oxdna/xstk oxdna_lj.cgdna
pair_coeff * * oxdna/coaxstk oxdna_lj.cgdna
# Real units
pair_style hybrid/overlay oxdna/excv oxdna/stk oxdna/hbond oxdna/xstk oxdna/coaxstk
pair_coeff * * oxdna/excv 11.92337812042065 5.9626 5.74965 11.92337812042065 4.38677 4.259 11.92337812042065 2.81094 2.72576
pair_coeff * * oxdna/stk seqdep 300.0 8.01727944817084 0.005279604 0.70439070204273 3.4072 7.6662 2.72576 6.3885 1.3 0.0 0.8 0.9 0.0 0.95 0.9 0.0 0.95 2.0 0.65 2.0 0.65
pair_coeff * * oxdna/hbond seqdep 0.0 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592654 0.7 4.0 1.570796327 0.45 4.0 1.570796327 0.45
pair_coeff 1 4 oxdna/hbond seqdep 6.42073911784652 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592654 0.7 4.0 1.570796327 0.45 4.0 1.570796327 0.45
pair_coeff 2 3 oxdna/hbond seqdep 6.42073911784652 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592654 0.7 4.0 1.570796327 0.45 4.0 1.570796327 0.45
pair_coeff * * oxdna/xstk 3.9029021145006 4.89785 5.74965 4.21641 5.57929 2.25 0.791592654 0.58 1.7 1.0 0.68 1.7 1.0 0.68 1.5 0.0 0.65 1.7 0.875 0.68 1.7 0.875 0.68
pair_coeff * * oxdna/coaxstk 3.77965257404268 3.4072 5.1108 1.87396 4.94044 2.0 2.541592654 0.65 1.3 0.0 0.8 0.9 0.0 0.95 0.9 0.0 0.95 2.0 -0.65 2.0 -0.65
pair_style hybrid/overlay oxdna/excv oxdna/stk oxdna/hbond oxdna/xstk oxdna/coaxstk
pair_coeff * * oxdna/excv oxdna_real.cgdna
pair_coeff * * oxdna/stk seqav 300.0 8.01727944817084 0.005279604 oxdna_real.cgdna
pair_coeff * * oxdna/hbond seqav oxdna_real.cgdna
pair_coeff 1 4 oxdna/hbond seqav oxdna_real.cgdna
pair_coeff 2 3 oxdna/hbond seqav oxdna_real.cgdna
pair_coeff * * oxdna/xstk oxdna_real.cgdna
pair_coeff * * oxdna/coaxstk oxdna_real.cgdna
.. note::
The coefficients in the above examples are provided in forms
compatible with both *units lj* and *units real* (see documentation
of :doc:`units <units>`). These can also be read from a potential
file with correct unit style by specifying the name of the
file. Several potential files for each unit style are included in the
``potentials`` directory of the LAMMPS distribution.
Description Description
""""""""""" """""""""""
The *oxdna* pair styles compute the pairwise-additive parts of the oxDNA force field The *oxdna* pair styles compute the pairwise-additive parts of the oxDNA
for coarse-grained modelling of DNA. The effective interaction between the nucleotides consists of potentials for the force field for coarse-grained modelling of DNA. The effective
excluded volume interaction *oxdna/excv*, the stacking *oxdna/stk*, cross-stacking *oxdna/xstk* interaction between the nucleotides consists of potentials for the
and coaxial stacking interaction *oxdna/coaxstk* as well excluded volume interaction *oxdna/excv*, the stacking *oxdna/stk*,
as the hydrogen-bonding interaction *oxdna/hbond* between complementary pairs of nucleotides on cross-stacking *oxdna/xstk* and coaxial stacking interaction
opposite strands. Average sequence or sequence-dependent stacking and base-pairing strengths *oxdna/coaxstk* as well as the hydrogen-bonding interaction
are supported :ref:`(Sulc) <Sulc1>`. Quasi-unique base-pairing between nucleotides can be achieved by using *oxdna/hbond* between complementary pairs of nucleotides on opposite
more complementary pairs of atom types like 5-8 and 6-7, 9-12 and 10-11, 13-16 and 14-15, etc. strands. Average sequence or sequence-dependent stacking and
This prevents the hybridization of in principle complementary bases within Ntypes/4 bases base-pairing strengths are supported :ref:`(Sulc) <Sulc1>`. Quasi-unique
up and down along the backbone. base-pairing between nucleotides can be achieved by using more
complementary pairs of atom types like 5-8 and 6-7, 9-12 and 10-11,
13-16 and 14-15, etc. This prevents the hybridization of in principle
complementary bases within Ntypes/4 bases up and down along the
backbone.
The exact functional form of the pair styles is rather complex. The exact functional form of the pair styles is rather complex. The
The individual potentials consist of products of modulation factors, individual potentials consist of products of modulation factors, which
which themselves are constructed from a number of more basic potentials themselves are constructed from a number of more basic potentials
(Morse, Lennard-Jones, harmonic angle and distance) as well as quadratic smoothing and modulation terms. (Morse, Lennard-Jones, harmonic angle and distance) as well as quadratic
We refer to :ref:`(Ouldridge-DPhil) <Ouldridge-DPhil1>` and :ref:`(Ouldridge) <Ouldridge1>` smoothing and modulation terms. We refer to :ref:`(Ouldridge-DPhil)
for a detailed description of the oxDNA force field. <Ouldridge-DPhil1>` and :ref:`(Ouldridge) <Ouldridge1>` for a detailed
description of the oxDNA force field.
.. note:: .. note::
These pair styles have to be used together with the related oxDNA bond style These pair styles have to be used together with the related oxDNA
*oxdna/fene* for the connectivity of the phosphate backbone (see also documentation of bond style *oxdna/fene* for the connectivity of the phosphate
:doc:`bond_style oxdna/fene <bond_oxdna>`). Most of the coefficients backbone (see also documentation of :doc:`bond_style oxdna/fene
in the above example have to be kept fixed and cannot be changed without reparameterizing the entire model. <bond_oxdna>`). Most of the coefficients in the above example have to
Exceptions are the first four coefficients after *oxdna/stk* (seq=seqdep, T=0.1, xi=1.3448 and kappa=2.6568 in the above example) be kept fixed and cannot be changed without reparameterizing the
and the first coefficient after *oxdna/hbond* (seq=seqdep in the above example). entire model. Exceptions are the first four coefficients after
When using a Langevin thermostat, e.g. through :doc:`fix langevin <fix_langevin>` *oxdna/stk* (seq=seqdep, T=0.1, xi=1.3448 and kappa=2.6568 and
or :doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>` corresponding *real unit* equivalents in the above examples) and the
the temperature coefficients have to be matched to the one used in the fix. first coefficient after *oxdna/hbond* (seq=seqdep in the above
example). When using a Langevin thermostat, e.g. through :doc:`fix
langevin <fix_langevin>` or :doc:`fix nve/dotc/langevin
<fix_nve_dotc_langevin>` the temperature coefficients have to be
matched to the one used in the fix.
.. note:: .. note::
These pair styles have to be used with the *atom_style hybrid bond ellipsoid oxdna* These pair styles have to be used with the *atom_style hybrid bond
(see documentation of :doc:`atom_style <atom_style>`). The *atom_style oxdna* ellipsoid oxdna* (see documentation of :doc:`atom_style
stores the 3'-to-5' polarity of the nucleotide strand, which is set through <atom_style>`). The *atom_style oxdna* stores the 3'-to-5' polarity
the bond topology in the data file. The first (second) atom in a bond definition of the nucleotide strand, which is set through the bond topology in
is understood to point towards the 3'-end (5'-end) of the strand. the data file. The first (second) atom in a bond definition is
understood to point towards the 3'-end (5'-end) of the strand.
Example input and data files for DNA duplexes can be found in examples/PACKAGES/cgdna/examples/oxDNA/ and /oxDNA2/. Example input and data files for DNA duplexes can be found in
A simple python setup tool which creates single straight or helical DNA strands, ``examples/PACKAGES/cgdna/examples/oxDNA/`` and ``.../oxDNA2/``. A
DNA duplexes or arrays of DNA duplexes can be found in examples/PACKAGES/cgdna/util/. simple python setup tool which creates single straight or helical DNA
strands, DNA duplexes or arrays of DNA duplexes can be found in
``examples/PACKAGES/cgdna/util/``.
Please cite :ref:`(Henrich) <Henrich1>` in any publication that uses Please cite :ref:`(Henrich) <Henrich1>` in any publication that uses
this implementation. An updated documentation that contains general information this implementation. An updated documentation that contains general
on the model, its implementation and performance as well as the structure of information on the model, its implementation and performance as well as
the data and input file can be found `here <PDF/CG-DNA.pdf>`_. the structure of the data and input file can be found `here
<PDF/CG-DNA.pdf>`_.
Please cite also the relevant oxDNA publications Please cite also the relevant oxDNA publications
:ref:`(Ouldridge) <Ouldridge1>`, :ref:`(Ouldridge) <Ouldridge1>`,
@ -115,6 +166,57 @@ and :ref:`(Sulc) <Sulc1>`.
---------- ----------
Potential file reading
""""""""""""""""""""""
For each pair style above the first non-modifiable argument can be a
filename, and if it is, no further arguments should be
supplied. Therefore the following command:
.. code-block:: LAMMPS
pair_coeff 1 4 oxdna/hbond seqav oxdna_lj.cgdna
will be interpreted as a request to read the corresponding hydrogen
bonding potential parameters from the file with the given name. The file
can define multiple potential parameters for both bonded and pair
interactions, but for the example pair interaction above there must
exist in the file a line of the form:
.. code-block:: LAMMPS
1 4 hbond <coefficients>
If potential customization is required, the potential file reading can
be mixed with the manual specification of the potential parameters. For
example, the following command:
.. code-block:: LAMMPS
pair_style hybrid/overlay oxdna/excv oxdna/stk oxdna/hbond oxdna/xstk oxdna/coaxstk
pair_coeff * * oxdna/excv oxdna_lj.cgdna
pair_coeff * * oxdna/stk seqav 0.1 1.3448 2.6568 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65
pair_coeff * * oxdna/hbond seqav oxdna_lj.cgdna
pair_coeff 1 4 oxdna/hbond seqav oxdna_lj.cgdna
pair_coeff 2 3 oxdna/hbond seqav oxdna_lj.cgdna
pair_coeff * * oxdna/xstk oxdna_lj.cgdna
pair_coeff * * oxdna/coaxstk 46.0 0.4 0.6 0.22 0.58 2.0 2.541592653589793 0.65 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 -0.65 2.0 -0.65
will read the stacking and coaxial stacking potential parameters from
the manual specification and all others from the potential file
*oxdna_lj.cgdna*.
There are sample potential files for each unit style in the
``potentials`` directory of the LAMMPS distribution. The potential file
unit system must align with the units defined via the :doc:`units
<units>` command. For conversion between different *LJ* and *real* unit
systems for oxDNA, the python tool *lj2real.py* located in the
``examples/PACKAGES/cgdna/util/`` directory can be used. This tool
assumes similar file structure to the examples found in
``examples/PACKAGES/cgdna/examples/``.
----------
Restrictions Restrictions
"""""""""""" """"""""""""

View File

@ -41,14 +41,14 @@ Syntax
*oxdna2/stk* args = seq T xi kappa 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65 *oxdna2/stk* args = seq T xi kappa 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65
seq = seqav (for average sequence stacking strength) or seqdep (for sequence-dependent stacking strength) seq = seqav (for average sequence stacking strength) or seqdep (for sequence-dependent stacking strength)
T = temperature (oxDNA units, 0.1 = 300 K) T = temperature (LJ units: 0.1 = 300 K, real units: 300 = 300 K)
xi = 1.3523 (temperature-independent coefficient in stacking strength) xi = 1.3523 (LJ units) or 8.06199211612242 (real units), temperature-independent coefficient in stacking strength
kappa = 2.6717 (coefficient of linear temperature dependence in stacking strength) kappa = 2.6717 (LJ units) or 0.005309213 (real units), coefficient of linear temperature dependence in stacking strength
*oxdna2/hbond* args = seq eps 8.0 0.4 0.75 0.34 0.7 1.5 0 0.7 1.5 0 0.7 1.5 0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45 *oxdna2/hbond* args = seq eps 8.0 0.4 0.75 0.34 0.7 1.5 0 0.7 1.5 0 0.7 1.5 0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
seq = seqav (for average sequence base-pairing strength) or seqdep (for sequence-dependent base-pairing strength) seq = seqav (for average sequence base-pairing strength) or seqdep (for sequence-dependent base-pairing strength)
eps = 1.0678 (between base pairs A-T and C-G) or 0 (all other pairs) eps = 1.0678 (LJ units) or 6.36589157849259 (real units), average hydrogen bonding strength between A-T and C-G Watson-Crick base pairs, 0 between all other pairs
*oxdna2/dh* args = T rhos qeff *oxdna2/dh* args = T rhos qeff
T = temperature (oxDNA units, 0.1 = 300 K) T = temperature (LJ units: 0.1 = 300 K, real units: 300 = 300 K)
rhos = salt concentration (mole per litre) rhos = salt concentration (mole per litre)
qeff = 0.815 (effective charge in elementary charges) qeff = 0.815 (effective charge in elementary charges)
@ -57,6 +57,7 @@ Examples
.. code-block:: LAMMPS .. code-block:: LAMMPS
# LJ units
pair_style hybrid/overlay oxdna2/excv oxdna2/stk oxdna2/hbond oxdna2/xstk oxdna2/coaxstk oxdna2/dh pair_style hybrid/overlay oxdna2/excv oxdna2/stk oxdna2/hbond oxdna2/xstk oxdna2/coaxstk oxdna2/dh
pair_coeff * * oxdna2/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32 pair_coeff * * oxdna2/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32
pair_coeff * * oxdna2/stk seqdep 0.1 1.3523 2.6717 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65 pair_coeff * * oxdna2/stk seqdep 0.1 1.3523 2.6717 6.0 0.4 0.9 0.32 0.75 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 2.0 0.65 2.0 0.65
@ -67,61 +68,169 @@ Examples
pair_coeff * * oxdna2/coaxstk 58.5 0.4 0.6 0.22 0.58 2.0 2.891592653589793 0.65 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 40.0 3.116592653589793 pair_coeff * * oxdna2/coaxstk 58.5 0.4 0.6 0.22 0.58 2.0 2.891592653589793 0.65 1.3 0 0.8 0.9 0 0.95 0.9 0 0.95 40.0 3.116592653589793
pair_coeff * * oxdna2/dh 0.1 0.5 0.815 pair_coeff * * oxdna2/dh 0.1 0.5 0.815
pair_style hybrid/overlay oxdna2/excv oxdna2/stk oxdna2/hbond oxdna2/xstk oxdna2/coaxstk oxdna2/dh
pair_coeff * * oxdna2/excv oxdna2_lj.cgdna
pair_coeff * * oxdna2/stk seqdep 0.1 1.3523 2.6717 oxdna2_lj.cgdna
pair_coeff * * oxdna2/hbond seqdep oxdna2_lj.cgdna
pair_coeff 1 4 oxdna2/hbond seqdep oxdna2_lj.cgdna
pair_coeff 2 3 oxdna2/hbond seqdep oxdna2_lj.cgdna
pair_coeff * * oxdna2/xstk oxdna2_lj.cgdna
pair_coeff * * oxdna2/coaxstk oxdna2_lj.cgdna
pair_coeff * * oxdna2/dh 0.1 0.5 oxdna2_lj.cgdna
# Real units
pair_style hybrid/overlay oxdna2/excv oxdna2/stk oxdna2/hbond oxdna2/xstk oxdna2/coaxstk oxdna2/dh
pair_coeff * * oxdna2/excv 11.92337812042065 5.9626 5.74965 11.92337812042065 4.38677 4.259 11.92337812042065 2.81094 2.72576
pair_coeff * * oxdna2/stk seqdep 300.0 8.06199211612242 0.005309213 0.70439070204273 3.4072 7.6662 2.72576 6.3885 1.3 0.0 0.8 0.9 0.0 0.95 0.9 0.0 0.95 2.0 0.65 2.0 0.65
pair_coeff * * oxdna2/hbond seqdep 0.0 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592654 0.7 4.0 1.570796327 0.45 4.0 1.570796327 0.45
pair_coeff 1 4 oxdna2/hbond seqdep 6.36589157849259 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592654 0.7 4.0 1.570796327 0.45 4.0 1.570796327 0.45
pair_coeff 2 3 oxdna2/hbond seqdep 6.36589157849259 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592654 0.7 4.0 1.570796327 0.45 4.0 1.570796327 0.45
pair_coeff * * oxdna2/xstk 3.9029021145006 4.89785 5.74965 4.21641 5.57929 2.25 0.791592654 0.58 1.7 1.0 0.68 1.7 1.0 0.68 1.5 0.0 0.65 1.7 0.875 0.68 1.7 0.875 0.68
pair_coeff * * oxdna2/coaxstk 4.80673207785863 3.4072 5.1108 1.87396 4.94044 2.0 2.891592653589793 0.65 1.3 0.0 0.8 0.9 0.0 0.95 0.9 0.0 0.95 40.0 3.116592653589793
pair_coeff * * oxdna2/dh 300.0 0.5 0.815
pair_style hybrid/overlay oxdna2/excv oxdna2/stk oxdna2/hbond oxdna2/xstk oxdna2/coaxstk oxdna2/dh
pair_coeff * * oxdna2/excv oxdna2_real.cgdna
pair_coeff * * oxdna2/stk seqdep 300.0 8.06199211612242 0.005309213 oxdna2_real.cgdna
pair_coeff * * oxdna2/hbond seqdep oxdna2_real.cgdna
pair_coeff 1 4 oxdna2/hbond seqdep oxdna2_real.cgdna
pair_coeff 2 3 oxdna2/hbond seqdep oxdna2_real.cgdna
pair_coeff * * oxdna2/xstk oxdna2_real.cgdna
pair_coeff * * oxdna2/coaxstk oxdna2_real.cgdna
pair_coeff * * oxdna2/dh 300.0 0.5 oxdna2_real.cgdna
.. note::
The coefficients in the above examples are provided in forms
compatible with both *units lj* and *units real* (see documentation
of :doc:`units <units>`). These can also be read from a potential
file with correct unit style by specifying the name of the
file. Several potential files for each unit style are included in the
``potentials`` directory of the LAMMPS distribution.
Description Description
""""""""""" """""""""""
The *oxdna2* pair styles compute the pairwise-additive parts of the oxDNA force field The *oxdna2* pair styles compute the pairwise-additive parts of the
for coarse-grained modelling of DNA. The effective interaction between the nucleotides consists of potentials for the oxDNA force field for coarse-grained modelling of DNA. The effective
excluded volume interaction *oxdna2/excv*, the stacking *oxdna2/stk*, cross-stacking *oxdna2/xstk* interaction between the nucleotides consists of potentials for the
and coaxial stacking interaction *oxdna2/coaxstk*, electrostatic Debye-Hueckel interaction *oxdna2/dh* excluded volume interaction *oxdna2/excv*, the stacking *oxdna2/stk*,
as well as the hydrogen-bonding interaction *oxdna2/hbond* between complementary pairs of nucleotides on cross-stacking *oxdna2/xstk* and coaxial stacking interaction
opposite strands. Average sequence or sequence-dependent stacking and base-pairing strengths *oxdna2/coaxstk*, electrostatic Debye-Hueckel interaction *oxdna2/dh* as
are supported :ref:`(Sulc) <Sulc2>`. Quasi-unique base-pairing between nucleotides can be achieved by using well as the hydrogen-bonding interaction *oxdna2/hbond* between
more complementary pairs of atom types like 5-8 and 6-7, 9-12 and 10-11, 13-16 and 14-15, etc. complementary pairs of nucleotides on opposite strands. Average sequence
This prevents the hybridization of in principle complementary bases within Ntypes/4 bases or sequence-dependent stacking and base-pairing strengths are supported
:ref:`(Sulc) <Sulc2>`. Quasi-unique base-pairing between nucleotides can
be achieved by using more complementary pairs of atom types like 5-8 and
6-7, 9-12 and 10-11, 13-16 and 14-15, etc. This prevents the
hybridization of in principle complementary bases within Ntypes/4 bases
up and down along the backbone. up and down along the backbone.
The exact functional form of the pair styles is rather complex. The exact functional form of the pair styles is rather complex. The
The individual potentials consist of products of modulation factors, individual potentials consist of products of modulation factors, which
which themselves are constructed from a number of more basic potentials themselves are constructed from a number of more basic potentials
(Morse, Lennard-Jones, harmonic angle and distance) as well as quadratic smoothing and modulation terms. (Morse, Lennard-Jones, harmonic angle and distance) as well as quadratic
We refer to :ref:`(Snodin) <Snodin2>` and the original oxDNA publications :ref:`(Ouldridge-DPhil) <Ouldridge-DPhil2>` smoothing and modulation terms. We refer to :ref:`(Snodin) <Snodin2>`
and :ref:`(Ouldridge) <Ouldridge2>` for a detailed description of the oxDNA2 force field. and the original oxDNA publications :ref:`(Ouldridge-DPhil)
<Ouldridge-DPhil2>` and :ref:`(Ouldridge) <Ouldridge2>` for a detailed
description of the oxDNA2 force field.
.. note:: .. note::
These pair styles have to be used together with the related oxDNA2 bond style These pair styles have to be used together with the related oxDNA2
*oxdna2/fene* for the connectivity of the phosphate backbone (see also documentation of bond style *oxdna2/fene* for the connectivity of the phosphate
:doc:`bond_style oxdna2/fene <bond_oxdna>`). Most of the coefficients backbone (see also documentation of :doc:`bond_style oxdna2/fene
in the above example have to be kept fixed and cannot be changed without reparameterizing the entire model. <bond_oxdna>`). Most of the coefficients in the above example have to
Exceptions are the first four coefficients after *oxdna2/stk* (seq=seqdep, T=0.1, xi=1.3523 and kappa=2.6717 in the above example), be kept fixed and cannot be changed without reparameterizing the
the first coefficient after *oxdna2/hbond* (seq=seqdep in the above example) and the three coefficients entire model. Exceptions are the first four coefficients after
after *oxdna2/dh* (T=0.1, rhos=0.5, qeff=0.815 in the above example). When using a Langevin thermostat *oxdna2/stk* (seq=seqdep, T=0.1, xi=1.3523 and kappa=2.6717 and
e.g. through :doc:`fix langevin <fix_langevin>` or :doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>` corresponding *real unit* equivalents in the above examples). the
the temperature coefficients have to be matched to the one used in the fix. first coefficient after *oxdna2/hbond* (seq=seqdep in the above
example) and the three coefficients after *oxdna2/dh* (T=0.1,
rhos=0.5, qeff=0.815 in the above example). When using a Langevin
thermostat e.g. through :doc:`fix langevin <fix_langevin>` or
:doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>` the temperature
coefficients have to be matched to the one used in the fix.
.. note:: .. note::
These pair styles have to be used with the *atom_style hybrid bond ellipsoid oxdna* These pair styles have to be used with the *atom_style hybrid bond
(see documentation of :doc:`atom_style <atom_style>`). The *atom_style oxdna* ellipsoid oxdna* (see documentation of :doc:`atom_style
stores the 3'-to-5' polarity of the nucleotide strand, which is set through <atom_style>`). The *atom_style oxdna* stores the 3'-to-5' polarity
the bond topology in the data file. The first (second) atom in a bond definition of the nucleotide strand, which is set through the bond topology in
is understood to point towards the 3'-end (5'-end) of the strand. the data file. The first (second) atom in a bond definition is
understood to point towards the 3'-end (5'-end) of the strand.
Example input and data files for DNA duplexes can be found in examples/PACKAGES/cgdna/examples/oxDNA/ and /oxDNA2/. Example input and data files for DNA duplexes can be found in
A simple python setup tool which creates single straight or helical DNA strands, ``examples/PACKAGES/cgdna/examples/oxDNA/`` and ``.../oxDNA2/``. A
DNA duplexes or arrays of DNA duplexes can be found in examples/PACKAGES/cgdna/util/. simple python setup tool which creates single straight or helical DNA
strands, DNA duplexes or arrays of DNA duplexes can be found in
``examples/PACKAGES/cgdna/util/``.
Please cite :ref:`(Henrich) <Henrich2>` in any publication that uses Please cite :ref:`(Henrich) <Henrich2>` in any publication that uses
this implementation. An updated documentation that contains general information this implementation. An updated documentation that contains general
on the model, its implementation and performance as well as the structure of information on the model, its implementation and performance as well as
the data and input file can be found `here <PDF/CG-DNA.pdf>`_. the structure of the data and input file can be found `here
<PDF/CG-DNA.pdf>`_.
Please cite also the relevant oxDNA2 publications Please cite also the relevant oxDNA2 publications
:ref:`(Snodin) <Snodin2>` and :ref:`(Sulc) <Sulc2>`. :ref:`(Snodin) <Snodin2>` and :ref:`(Sulc) <Sulc2>`.
---------- ----------
Potential file reading
""""""""""""""""""""""
For each pair style above the first non-modifiable argument can be a
filename (with exception of Debye-Hueckel, for which the effective
charge argument can be a filename), and if it is, no further arguments
should be supplied. Therefore the following command:
.. code-block:: LAMMPS
pair_coeff 1 4 oxdna2/hbond seqdep oxdna_real.cgdna
will be interpreted as a request to read the corresponding hydrogen
bonding potential parameters from the file with the given name. The
file can define multiple potential parameters for both bonded and pair
interactions, but for the example pair interaction above there must
exist in the file a line of the form:
.. code-block:: LAMMPS
1 4 hbond <coefficients>
If potential customization is required, the potential file reading can
be mixed with the manual specification of the potential parameters. For
example, the following command:
.. code-block:: LAMMPS
pair_style hybrid/overlay oxdna2/excv oxdna2/stk oxdna2/hbond oxdna2/xstk oxdna2/coaxstk oxdna2/dh
pair_coeff * * oxdna2/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32
pair_coeff * * oxdna2/stk seqdep 0.1 1.3523 2.6717 oxdna2_lj.cgdna
pair_coeff * * oxdna2/hbond seqdep oxdna2_lj.cgdna
pair_coeff 1 4 oxdna2/hbond seqdep oxdna2_lj.cgdna
pair_coeff 2 3 oxdna2/hbond seqdep oxdna2_lj.cgdna
pair_coeff * * oxdna2/xstk oxdna2_lj.cgdna
pair_coeff * * oxdna2/coaxstk oxdna2_lj.cgdna
pair_coeff * * oxdna2/dh 0.1 0.5 0.815
will read the excluded volume and Debye-Hueckel effective charge *qeff*
parameters from the manual specification and all others from the
potential file *oxdna2_lj.cgdna*.
There are sample potential files for each unit style in the ``potentials``
directory of the LAMMPS distribution. The potential file unit system
must align with the units defined via the :doc:`units <units>`
command. For conversion between different *LJ* and *real* unit systems
for oxDNA, the python tool *lj2real.py* located in the
``examples/PACKAGES/cgdna/util/`` directory can be used. This tool assumes
similar file structure to the examples found in
``examples/PACKAGES/cgdna/examples/``.
----------
Restrictions Restrictions
"""""""""""" """"""""""""

View File

@ -41,14 +41,14 @@ Syntax
*oxrna2/stk* args = seq T xi kappa 6.0 0.43 0.93 0.35 0.78 0.9 0 0.95 0.9 0 0.95 1.3 0 0.8 1.3 0 0.8 2.0 0.65 2.0 0.65 *oxrna2/stk* args = seq T xi kappa 6.0 0.43 0.93 0.35 0.78 0.9 0 0.95 0.9 0 0.95 1.3 0 0.8 1.3 0 0.8 2.0 0.65 2.0 0.65
seq = seqav (for average sequence stacking strength) or seqdep (for sequence-dependent stacking strength) seq = seqav (for average sequence stacking strength) or seqdep (for sequence-dependent stacking strength)
T = temperature (oxDNA units, 0.1 = 300 K) T = temperature (LJ units: 0.1 = 300 K, real units: 300 = 300 K)
xi = 1.40206 (temperature-independent coefficient in stacking strength) xi = 1.40206 (LJ units) or 8.35864576375849 (real units), temperature-independent coefficient in stacking strength
kappa = 2.77 (coefficient of linear temperature dependence in stacking strength) kappa = 2.77 (LJ units) or 0.005504556 (real units), coefficient of linear temperature dependence in stacking strength
*oxrna2/hbond* args = seq eps 8.0 0.4 0.75 0.34 0.7 1.5 0 0.7 1.5 0 0.7 1.5 0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45 *oxrna2/hbond* args = seq eps 8.0 0.4 0.75 0.34 0.7 1.5 0 0.7 1.5 0 0.7 1.5 0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
seq = seqav (for average sequence base-pairing strength) or seqdep (for sequence-dependent base-pairing strength) seq = seqav (for average sequence base-pairing strength) or seqdep (for sequence-dependent base-pairing strength)
eps = 0.870439 (between base pairs A-T, C-G and G-T) or 0 (all other pairs) eps = 0.870439 (LJ units) or 5.18928666388042 (real units), average hydrogen bonding strength between A-U and C-G Watson-Crick and G-U wobble base pairs, 0 between all other pairs
*oxrna2/dh* args = T rhos qeff *oxrna2/dh* args = T rhos qeff
T = temperature (oxDNA units, 0.1 = 300 K) T = temperature (LJ units: 0.1 = 300 K, real units: 300 = 300 K)
rhos = salt concentration (mole per litre) rhos = salt concentration (mole per litre)
qeff = 1.02455 (effective charge in elementary charges) qeff = 1.02455 (effective charge in elementary charges)
@ -57,6 +57,7 @@ Examples
.. code-block:: LAMMPS .. code-block:: LAMMPS
# LJ units
pair_style hybrid/overlay oxrna2/excv oxrna2/stk oxrna2/hbond oxrna2/xstk oxrna2/coaxstk oxrna2/dh pair_style hybrid/overlay oxrna2/excv oxrna2/stk oxrna2/hbond oxrna2/xstk oxrna2/coaxstk oxrna2/dh
pair_coeff * * oxrna2/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32 pair_coeff * * oxrna2/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32
pair_coeff * * oxrna2/stk seqdep 0.1 1.40206 2.77 6.0 0.43 0.93 0.35 0.78 0.9 0 0.95 0.9 0 0.95 1.3 0 0.8 1.3 0 0.8 2.0 0.65 2.0 0.65 pair_coeff * * oxrna2/stk seqdep 0.1 1.40206 2.77 6.0 0.43 0.93 0.35 0.78 0.9 0 0.95 0.9 0 0.95 1.3 0 0.8 1.3 0 0.8 2.0 0.65 2.0 0.65
@ -68,58 +69,168 @@ Examples
pair_coeff * * oxrna2/coaxstk 80 0.5 0.6 0.42 0.58 2.0 2.592 0.65 1.3 0.151 0.8 0.9 0.685 0.95 0.9 0.685 0.95 2.0 -0.65 2.0 -0.65 pair_coeff * * oxrna2/coaxstk 80 0.5 0.6 0.42 0.58 2.0 2.592 0.65 1.3 0.151 0.8 0.9 0.685 0.95 0.9 0.685 0.95 2.0 -0.65 2.0 -0.65
pair_coeff * * oxrna2/dh 0.1 0.5 1.02455 pair_coeff * * oxrna2/dh 0.1 0.5 1.02455
pair_style hybrid/overlay oxrna2/excv oxrna2/stk oxrna2/hbond oxrna2/xstk oxrna2/coaxstk oxrna2/dh
pair_coeff * * oxrna2/excv oxrna2_lj.cgdna
pair_coeff * * oxrna2/stk seqdep 0.1 1.40206 2.77 oxrna2_lj.cgdna
pair_coeff * * oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff 1 4 oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff 2 3 oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff 3 4 oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff * * oxrna2/xstk oxrna2_lj.cgdna
pair_coeff * * oxrna2/coaxstk oxrna2_lj.cgdna
pair_coeff * * oxrna2/dh 0.1 0.5 oxrna2_lj.cgdna
# Real units
pair_style hybrid/overlay oxrna2/excv oxrna2/stk oxrna2/hbond oxrna2/xstk oxrna2/coaxstk oxrna2/dh
pair_coeff * * oxrna2/excv 11.92337812042065 5.9626 5.74965 11.92337812042065 4.38677 4.259 11.92337812042065 2.81094 2.72576
pair_coeff * * oxrna2/stk seqdep 300.0 8.35864576375849 0.005504556 0.70439070204273 3.66274 7.92174 2.9813 6.64404 0.9 0.0 0.95 0.9 0.0 0.95 1.3 0.0 0.8 1.3 0.0 0.8 2.0 0.65 2.0 0.65
pair_coeff * * oxrna2/hbond seqdep 0.0 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
pair_coeff 1 4 oxrna2/hbond seqdep 5.18928666388042 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
pair_coeff 2 3 oxrna2/hbond seqdep 5.18928666388042 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
pair_coeff 3 4 oxrna2/hbond seqdep 5.18928666388042 0.93918760272364 3.4072 6.3885 2.89612 5.9626 1.5 0.0 0.7 1.5 0.0 0.7 1.5 0.0 0.7 0.46 3.141592653589793 0.7 4.0 1.5707963267948966 0.45 4.0 1.5707963267948966 0.45
pair_coeff * * oxrna2/xstk 4.92690859644113 4.259 5.1108 3.57756 4.94044 2.25 0.505 0.58 1.7 1.266 0.68 1.7 1.266 0.68 1.7 0.309 0.68 1.7 0.309 0.68
pair_coeff * * oxrna2/coaxstk 6.57330882442206 4.259 5.1108 3.57756 4.94044 2.0 2.592 0.65 1.3 0.151 0.8 0.9 0.685 0.95 0.9 0.685 0.95 2.0 -0.65 2.0 -0.65
pair_coeff * * oxrna2/dh 300.0 0.5 1.02455
pair_style hybrid/overlay oxrna2/excv oxrna2/stk oxrna2/hbond oxrna2/xstk oxrna2/coaxstk oxrna2/dh
pair_coeff * * oxrna2/excv oxrna2_real.cgdna
pair_coeff * * oxrna2/stk seqdep 300.0 8.35864576375849 0.005504556 oxrna2_real.cgdna
pair_coeff * * oxrna2/hbond seqdep oxrna2_real.cgdna
pair_coeff 1 4 oxrna2/hbond seqdep oxrna2_real.cgdna
pair_coeff 2 3 oxrna2/hbond seqdep oxrna2_real.cgdna
pair_coeff 3 4 oxrna2/hbond seqdep oxrna2_real.cgdna
pair_coeff * * oxrna2/xstk oxrna2_real.cgdna
pair_coeff * * oxrna2/coaxstk oxrna2_real.cgdna
pair_coeff * * oxrna2/dh 300.0 0.5 oxrna2_real.cgdna
.. note::
The coefficients in the above examples are provided in forms
compatible with both *units lj* and *units real* (see documentation
of :doc:`units <units>`). These can also be read from a potential
file with correct unit style by specifying the name of the
file. Several potential files for each unit style are included in the
``potentials`` directory of the LAMMPS distribution.
Description Description
""""""""""" """""""""""
The *oxrna2* pair styles compute the pairwise-additive parts of the oxDNA force field The *oxrna2* pair styles compute the pairwise-additive parts of the
for coarse-grained modelling of DNA. The effective interaction between the nucleotides consists of potentials for the oxDNA force field for coarse-grained modelling of RNA. The effective
excluded volume interaction *oxrna2/excv*, the stacking *oxrna2/stk*, cross-stacking *oxrna2/xstk* interaction between the nucleotides consists of potentials for the
and coaxial stacking interaction *oxrna2/coaxstk*, electrostatic Debye-Hueckel interaction *oxrna2/dh* excluded volume interaction *oxrna2/excv*, the stacking *oxrna2/stk*,
as well as the hydrogen-bonding interaction *oxrna2/hbond* between complementary pairs of nucleotides on cross-stacking *oxrna2/xstk* and coaxial stacking interaction
opposite strands. Average sequence or sequence-dependent stacking and base-pairing strengths *oxrna2/coaxstk*, electrostatic Debye-Hueckel interaction *oxrna2/dh* as
are supported :ref:`(Sulc2) <Sulc32>`. Quasi-unique base-pairing between nucleotides can be achieved by using well as the hydrogen-bonding interaction *oxrna2/hbond* between
more complementary pairs of atom types like 5-8 and 6-7, 9-12 and 10-11, 13-16 and 14-15, etc. complementary pairs of nucleotides on opposite strands. Average sequence
This prevents the hybridization of in principle complementary bases within Ntypes/4 bases or sequence-dependent stacking and base-pairing strengths are supported
:ref:`(Sulc2) <Sulc32>`. Quasi-unique base-pairing between nucleotides
can be achieved by using more complementary pairs of atom types like 5-8
and 6-7, 9-12 and 10-11, 13-16 and 14-15, etc. This prevents the
hybridization of in principle complementary bases within Ntypes/4 bases
up and down along the backbone. up and down along the backbone.
The exact functional form of the pair styles is rather complex. The exact functional form of the pair styles is rather complex. The
The individual potentials consist of products of modulation factors, individual potentials consist of products of modulation factors, which
which themselves are constructed from a number of more basic potentials themselves are constructed from a number of more basic potentials
(Morse, Lennard-Jones, harmonic angle and distance) as well as quadratic smoothing and modulation terms. (Morse, Lennard-Jones, harmonic angle and distance) as well as quadratic
We refer to :ref:`(Sulc1) <Sulc31>` and the original oxDNA publications :ref:`(Ouldridge-DPhil) <Ouldridge-DPhil3>` smoothing and modulation terms. We refer to :ref:`(Sulc1) <Sulc31>` and
and :ref:`(Ouldridge) <Ouldridge3>` for a detailed description of the oxRNA2 force field. the original oxDNA publications :ref:`(Ouldridge-DPhil)
<Ouldridge-DPhil3>` and :ref:`(Ouldridge) <Ouldridge3>` for a detailed
description of the oxRNA2 force field.
.. note:: .. note::
These pair styles have to be used together with the related oxDNA2 bond style These pair styles have to be used together with the related oxDNA2
*oxrna2/fene* for the connectivity of the phosphate backbone (see also documentation of bond style *oxrna2/fene* for the connectivity of the phosphate
:doc:`bond_style oxrna2/fene <bond_oxdna>`). Most of the coefficients backbone (see also documentation of :doc:`bond_style oxrna2/fene
in the above example have to be kept fixed and cannot be changed without reparameterizing the entire model. <bond_oxdna>`). Most of the coefficients in the above example have to
Exceptions are the first four coefficients after *oxrna2/stk* (seq=seqdep, T=0.1, xi=1.40206 and kappa=2.77 in the above example), be kept fixed and cannot be changed without reparameterizing the
the first coefficient after *oxrna2/hbond* (seq=seqdep in the above example) and the three coefficients entire model. Exceptions are the first four coefficients after
after *oxrna2/dh* (T=0.1, rhos=0.5, qeff=1.02455 in the above example). When using a Langevin thermostat *oxrna2/stk* (seq=seqdep, T=0.1, xi=1.40206 and kappa=2.77 and
e.g. through :doc:`fix langevin <fix_langevin>` or :doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>` corresponding *real unit* equivalents in the above examples), the
the temperature coefficients have to be matched to the one used in the fix. first coefficient after *oxrna2/hbond* (seq=seqdep in the above
example) and the three coefficients after *oxrna2/dh* (T=0.1,
rhos=0.5, qeff=1.02455 in the above example). When using a Langevin
thermostat e.g. through :doc:`fix langevin <fix_langevin>` or
:doc:`fix nve/dotc/langevin <fix_nve_dotc_langevin>` the temperature
coefficients have to be matched to the one used in the fix.
.. note:: .. note::
These pair styles have to be used with the *atom_style hybrid bond ellipsoid oxdna* These pair styles have to be used with the *atom_style hybrid bond
(see documentation of :doc:`atom_style <atom_style>`). The *atom_style oxdna* ellipsoid oxdna* (see documentation of :doc:`atom_style
stores the 3'-to-5' polarity of the nucleotide strand, which is set through <atom_style>`). The *atom_style oxdna* stores the 3'-to-5' polarity
the bond topology in the data file. The first (second) atom in a bond definition of the nucleotide strand, which is set through the bond topology in
is understood to point towards the 3'-end (5'-end) of the strand. the data file. The first (second) atom in a bond definition is
understood to point towards the 3'-end (5'-end) of the strand.
Example input and data files for DNA duplexes can be found in examples/PACKAGES/cgdna/examples/oxDNA/ and /oxDNA2/. Example input and data files for DNA duplexes can be found in
A simple python setup tool which creates single straight or helical DNA strands, ``examples/PACKAGES/cgdna/examples/oxDNA/`` and ``.../oxDNA2/``. A simple python
DNA duplexes or arrays of DNA duplexes can be found in examples/PACKAGES/cgdna/util/. setup tool which creates single straight or helical DNA strands, DNA
duplexes or arrays of DNA duplexes can be found in
``examples/PACKAGES/cgdna/util/``.
Please cite :ref:`(Henrich) <Henrich3>` in any publication that uses Please cite :ref:`(Henrich) <Henrich3>` in any publication that uses
this implementation. The article contains general information this implementation. The article contains general information on the
on the model, its implementation and performance as well as the structure of model, its implementation and performance as well as the structure of
the data and input file. The preprint version of the article can be found the data and input file. The preprint version of the article can be
`here <PDF/CG-DNA.pdf>`_. found `here <PDF/CG-DNA.pdf>`_. Please cite also the relevant oxRNA2
Please cite also the relevant oxRNA2 publications publications :ref:`(Sulc1) <Sulc31>` and :ref:`(Sulc2) <Sulc32>`.
:ref:`(Sulc1) <Sulc31>` and :ref:`(Sulc2) <Sulc32>`.
----------
Potential file reading
""""""""""""""""""""""
For each pair style above the first non-modifiable argument can be a
filename (with exception of Debye-Hueckel, for which the effective
charge argument can be a filename), and if it is, no further arguments
should be supplied. Therefore the following command:
.. code-block:: LAMMPS
pair_coeff 3 4 oxrna2/hbond seqdep oxrna2_lj.cgdna
will be interpreted as a request to read the corresponding hydrogen
bonding potential parameters from the file with the given name. The
file can define multiple potential parameters for both bonded and pair
interactions, but for the example pair interaction above there must
exist in the file a line of the form:
.. code-block:: LAMMPS
3 4 hbond <coefficients>
If potential customization is required, the potential file reading can
be mixed with the manual specification of the potential parameters. For
example, the following command:
.. code-block:: LAMMPS
pair_style hybrid/overlay oxrna2/excv oxrna2/stk oxrna2/hbond oxrna2/xstk oxrna2/coaxstk oxrna2/dh
pair_coeff * * oxrna2/excv 2.0 0.7 0.675 2.0 0.515 0.5 2.0 0.33 0.32
pair_coeff * * oxrna2/stk seqdep 0.1 1.40206 2.77 oxrna2_lj.cgdna
pair_coeff * * oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff 1 4 oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff 2 3 oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff 3 4 oxrna2/hbond seqdep oxrna2_lj.cgdna
pair_coeff * * oxrna2/xstk oxrna2_lj.cgdna
pair_coeff * * oxrna2/coaxstk oxrna2_lj.cgdna
pair_coeff * * oxrna2/dh 0.1 0.5 1.02455
will read the excluded volume and Debye-Hueckel effective charge *qeff*
parameters from the manual specification and all others from the
potential file *oxrna2_lj.cgdna*.
There are sample potential files for each unit style in the
``potentials`` directory of the LAMMPS distribution. The potential file
unit system must align with the units defined via the :doc:`units
<units>` command. For conversion between different *LJ* and *real* unit
systems for oxDNA, the python tool *lj2real.py* located in the
``examples/PACKAGES/cgdna/util/`` directory can be used. This tool
assumes similar file structure to the examples found in
``examples/PACKAGES/cgdna/examples/``.
---------- ----------

View File

@ -1,8 +1,11 @@
.. index:: pair_style pod .. index:: pair_style pod
.. index:: pair_style pod/kk
pair_style pod command pair_style pod command
======================== ========================
Accelerator Variants: *pod/kk*
Syntax Syntax
"""""" """"""
@ -24,29 +27,33 @@ Description
.. versionadded:: 22Dec2022 .. versionadded:: 22Dec2022
Pair style *pod* defines the proper orthogonal descriptor (POD) Pair style *pod* defines the proper orthogonal descriptor (POD)
potential :ref:`(Nguyen) <Nguyen20221>`. The mathematical definition of potential :ref:`(Nguyen and Rohskopf) <Nguyen20222b>`,
the POD potential is described from :doc:`fitpod <fitpod_command>`, which is :ref:`(Nguyen2023) <Nguyen20232b>`, :ref:`(Nguyen2024) <Nguyen20242b>`,
used to fit the POD potential to *ab initio* energy and force data. and :ref:`(Nguyen and Sema) <Nguyen20243b>`. The :doc:`fitpod
<fitpod_command>` is used to fit the POD potential.
Only a single pair_coeff command is used with the *pod* style which Only a single pair_coeff command is used with the *pod* style which
specifies a POD parameter file followed by a coefficient file. specifies a POD parameter file followed by a coefficient file, a
projection matrix file, and a centroid file.
The coefficient file (``Ta_coefficients.pod``) contains coefficients for the The POD parameter file (``Ta_param.pod``) can contain blank and comment
POD potential. The top of the coefficient file can contain any number of lines (start with #) anywhere. Each non-blank non-comment line must
blank and comment lines (start with #), but follows a strict format contain one keyword/value pair. See :doc:`fitpod <fitpod_command>` for
after that. The first non-blank non-comment line must contain: the description of all the keywords that can be assigned in the
parameter file.
* POD_coefficients: *ncoeff* The coefficient file (``Ta_coefficients.pod``) contains coefficients for
the POD potential. The top of the coefficient file can contain any
number of blank and comment lines (start with #), but follows a strict
format after that. The first non-blank non-comment line must contain:
This is followed by *ncoeff* coefficients, one per line. The coefficient * model_coefficients: *ncoeff* *nproj* *ncentroid*
This is followed by *ncoeff* coefficients, *nproj* projection matrix entries,
and *ncentroid* centroid coordinates, one per line. The coefficient
file is generated after training the POD potential using :doc:`fitpod file is generated after training the POD potential using :doc:`fitpod
<fitpod_command>`. <fitpod_command>`.
The POD parameter file (``Ta_param.pod``) can contain blank and comment lines
(start with #) anywhere. Each non-blank non-comment line must contain
one keyword/value pair. See :doc:`fitpod <fitpod_command>` for the description
of all the keywords that can be assigned in the parameter file.
As an example, if a LAMMPS indium phosphide simulation has 4 atoms As an example, if a LAMMPS indium phosphide simulation has 4 atoms
types, with the first two being indium and the third and fourth being types, with the first two being indium and the third and fourth being
phophorous, the pair_coeff command would look like this: phophorous, the pair_coeff command would look like this:
@ -67,7 +74,33 @@ the *hybrid* pair style. The NULL values are placeholders for atom
types that will be used with other potentials. types that will be used with other potentials.
Examples about training and using POD potentials are found in the Examples about training and using POD potentials are found in the
directory lammps/examples/PACKAGES/pod. directory lammps/examples/PACKAGES/pod and the Github repo https://github.com/cesmix-mit/pod-examples.
----------
Mixing, shift, table, tail correction, restart, rRESPA info
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
For atom type pairs I,J and I != J, where types I and J correspond to
two different element types, mixing is performed by LAMMPS with
user-specifiable parameters as described above. You never need to
specify a pair_coeff command with I != J arguments for this style.
This pair style does not support the :doc:`pair_modify <pair_modify>`
shift, table, and tail options.
This pair style does not write its information to :doc:`binary restart
files <restart>`, since it is stored in potential files. Thus, you need
to re-specify the pair_style and pair_coeff commands in an input script
that reads a restart file.
This pair style can only be used via the *pair* keyword of the
:doc:`run_style respa <run_style>` command. It does not support the
*inner*, *middle*, *outer* keywords.
----------
.. include:: accel_styles.rst
---------- ----------
@ -78,12 +111,14 @@ This style is part of the ML-POD package. It is only enabled if LAMMPS
was built with that package. See the :doc:`Build package was built with that package. See the :doc:`Build package
<Build_package>` page for more info. <Build_package>` page for more info.
This pair style does not compute per-atom energies and per-atom stresses.
Related commands Related commands
"""""""""""""""" """"""""""""""""
:doc:`fitpod <fitpod_command>`, :doc:`fitpod <fitpod_command>`,
:doc:`compute pod/atom <compute_pod_atom>`,
:doc:`compute podd/atom <compute_pod_atom>`,
:doc:`compute pod/local <compute_pod_atom>`,
:doc:`compute pod/global <compute_pod_atom>`
Default Default
""""""" """""""
@ -92,6 +127,20 @@ none
---------- ----------
.. _Nguyen20221: .. _Nguyen20222b:
**(Nguyen and Rohskopf)** Nguyen and Rohskopf, Journal of Computational Physics, 480, 112030, (2023).
.. _Nguyen20232b:
**(Nguyen2023)** Nguyen, Physical Review B, 107(14), 144103, (2023).
.. _Nguyen20242b:
**(Nguyen2024)** Nguyen, Journal of Computational Physics, 113102, (2024).
.. _Nguyen20243b:
**(Nguyen and Sema)** Nguyen and Sema, https://arxiv.org/abs/2405.00306, (2024).
**(Nguyen)** Nguyen and Rohskopf, arXiv preprint arXiv:2209.02362 (2022).

View File

@ -1,11 +1,12 @@
.. index:: pair_style soft .. index:: pair_style soft
.. index:: pair_style soft/gpu .. index:: pair_style soft/gpu
.. index:: pair_style soft/kk
.. index:: pair_style soft/omp .. index:: pair_style soft/omp
pair_style soft command pair_style soft command
======================= =======================
Accelerator Variants: *soft/gpu*, *soft/omp* Accelerator Variants: *soft/gpu*, *soft/kk*, *soft/omp*
Syntax Syntax
"""""" """"""

View File

@ -108,6 +108,7 @@ accelerated styles exist.
* :doc:`none <pair_none>` - turn off pairwise interactions * :doc:`none <pair_none>` - turn off pairwise interactions
* :doc:`hybrid <pair_hybrid>` - multiple styles of pairwise interactions * :doc:`hybrid <pair_hybrid>` - multiple styles of pairwise interactions
* :doc:`hybrid/molecular <pair_hybrid>` - different pair styles for intra- and inter-molecular interactions
* :doc:`hybrid/overlay <pair_hybrid>` - multiple styles of superposed pairwise interactions * :doc:`hybrid/overlay <pair_hybrid>` - multiple styles of superposed pairwise interactions
* :doc:`hybrid/scaled <pair_hybrid>` - multiple styles of scaled superposed pairwise interactions * :doc:`hybrid/scaled <pair_hybrid>` - multiple styles of scaled superposed pairwise interactions
* :doc:`zero <pair_zero>` - neighbor list but no interactions * :doc:`zero <pair_zero>` - neighbor list but no interactions
@ -171,6 +172,7 @@ accelerated styles exist.
* :doc:`coul/wolf <pair_coul>` - Coulomb via Wolf potential * :doc:`coul/wolf <pair_coul>` - Coulomb via Wolf potential
* :doc:`coul/wolf/cs <pair_cs>` - Coulomb via Wolf potential with core/shell adjustments * :doc:`coul/wolf/cs <pair_cs>` - Coulomb via Wolf potential with core/shell adjustments
* :doc:`dpd <pair_dpd>` - dissipative particle dynamics (DPD) * :doc:`dpd <pair_dpd>` - dissipative particle dynamics (DPD)
* :doc:`dpd/coul/slater/long <pair_dpd_coul_slater_long>` - dissipative particle dynamics (DPD) with electrostatic interactions
* :doc:`dpd/ext <pair_dpd_ext>` - generalized force field for DPD * :doc:`dpd/ext <pair_dpd_ext>` - generalized force field for DPD
* :doc:`dpd/ext/tstat <pair_dpd_ext>` - pairwise DPD thermostatting with generalized force field * :doc:`dpd/ext/tstat <pair_dpd_ext>` - pairwise DPD thermostatting with generalized force field
* :doc:`dpd/fdt <pair_dpd_fdt>` - DPD for constant temperature and pressure * :doc:`dpd/fdt <pair_dpd_fdt>` - DPD for constant temperature and pressure
@ -382,6 +384,7 @@ accelerated styles exist.
* :doc:`tracker <pair_tracker>` - monitor information about pairwise interactions * :doc:`tracker <pair_tracker>` - monitor information about pairwise interactions
* :doc:`tri/lj <pair_tri_lj>` - LJ potential between triangles * :doc:`tri/lj <pair_tri_lj>` - LJ potential between triangles
* :doc:`ufm <pair_ufm>` - * :doc:`ufm <pair_ufm>` -
* :doc:`uf3 <pair_uf3>` - UF3 machine-learning potential
* :doc:`vashishta <pair_vashishta>` - Vashishta 2-body and 3-body potential * :doc:`vashishta <pair_vashishta>` - Vashishta 2-body and 3-body potential
* :doc:`vashishta/table <pair_vashishta>` - * :doc:`vashishta/table <pair_vashishta>` -
* :doc:`wf/cut <pair_wf_cut>` - Wang-Frenkel Potential for short-ranged interactions * :doc:`wf/cut <pair_wf_cut>` - Wang-Frenkel Potential for short-ranged interactions

213
doc/src/pair_uf3.rst Normal file
View File

@ -0,0 +1,213 @@
.. index:: pair_style uf3
.. index:: pair_style uf3/kk
pair_style uf3 command
======================
Accelerator Variants: *uf3/kk*
Syntax
""""""
.. code-block:: LAMMPS
pair_style style BodyFlag
* style = *uf3* or *uf3/kk*
.. parsed-literal::
BodyFlag = Indicates whether to calculate only 2-body or 2 and 3-body interactions. Possible values: 2 or 3
Examples
""""""""
.. code-block:: LAMMPS
pair_style uf3 3
pair_coeff * * Nb.uf3 Nb
pair_style uf3 2
pair_coeff * * NbSn.uf3 Nb Sn
pair_style uf3 3
pair_coeff * * NbSn.uf3 Nb Sn
Description
"""""""""""
.. versionadded:: 27June2024
The *uf3* style computes the :ref:`Ultra-Fast Force Fields (UF3)
<Xie23>` potential, a machine-learning interatomic potential. In UF3,
the total energy of the system is defined via two- and three-body
interactions:
.. math::
E & = \sum_{i,j} V_2(r_{ij}) + \sum_{i,j,k} V_3 (r_{ij},r_{ik},r_{jk}) \\
V_2(r_{ij}) & = \sum_{n=0}^N c_n B_n(r_{ij}) \\
V_3 (r_{ij},r_{ik},r_{jk}) & = \sum_{l=0}^{N_l} \sum_{m=0}^{N_m} \sum_{n=0}^{N_n} c_{l,m,n} B_l(r_{ij}) B_m(r_{ik}) B_n(r_{jk})
where :math:`V_2(r_{ij})` and :math:`V_3 (r_{ij},r_{ik},r_{jk})` are the
two- and three-body interactions, respectively. For the two-body the
summation is over all neighbors J and for the three-body the summation
is over all neighbors J and K of atom I within a cutoff distance
determined from the potential files. :math:`B_n(r_{ij})` are the cubic
b-spline basis, :math:`c_n` and :math:`c_{l,m,n}` are the machine-learned
interaction parameters and :math:`N`, :math:`N_l`, :math:`N_m`, and
:math:`N_n` denote the number of basis functions per spline or tensor
spline dimension.
With *uf3* style only a single pair_coeff command is used to indicate the
UF3 LAMMPS potential file containing all the two- and three-body interactions
followed by N additional arguments specifying the mapping of UF3 elements to
LAMMPS atom types, where N is the number of LAMMPS atom types:
* UF3 LAMMPS potential file
* N elements names = mapping of UF3 elements to atom types
As an example, if a LAMMPS simulation contains 2 atom types (elements
'A' and 'B'), the pair_coeff command will be:
.. code-block:: LAMMPS
pair_style uf3 3
pair_coeff * * AB.uf3 A B
The AB.uf3 file should contain all two-body (A-A, A-B, B-B) and three-body
(A-A-A, A-A-B, A-B-B, B-A-A, B-A-B, B-B-B).
If a value of "2" is specified in the :code:`pair_style uf3` command,
only the two-body potentials are needed. For 3-body interaction the
first atom type is the central atom. We recommend using the
:code:`generate_uf3_lammps_pots.py` script (found `here
<https://github.com/uf3/uf3/tree/develop/lammps_plugin/scripts>`_) for
generating the UF3 LAMMPS potential file from the UF3 JSON potentials.
----------
UF3 LAMMPS potential file in the *potentials* directory of the LAMMPS
distribution have a ".uf3" suffix. The interaction block in UF3 LAMMPS potential
file should start with :code:`#UF3 POT` and end with :code:`#` characters.
Following shows the format of a generic 2-body and 3-body potential block in
UF3 LAMMPS potential file-
.. code-block:: LAMMPS
#UF3 POT UNITS: units DATE: POT_GEN_DATE AUTHOR: AUTHOR_NAME CITATION: CITE
2B ELEMENT1 ELEMENT2 LEADING_TRIM TRAILING_TRIM
Rij_CUTOFF NUM_OF_KNOTS
BSPLINE_KNOTS
NUM_OF_COEFF
COEFF
#
#UF3 POT UNITS: units DATE: POT_GEN_DATE AUTHOR: AUTHOR_NAME CITATION: CITE
3B ELEMENT1 ELEMENT2 ELEMENT3 LEADING_TRIM TRAILING_TRIM
Rjk_CUTOFF Rik_CUTOFF Rij_CUTOFF NUM_OF_KNOTS_JK NUM_OF_KNOTS_IK NUM_OF_KNOTS_IJ
BSPLINE_KNOTS_FOR_JK
BSPLINE_KNOTS_FOR_IK
BSPLINE_KNOTS_FOR_IJ
SHAPE_OF_COEFF_MATRIX[I][J][K]
COEFF_MATRIX[0][0][K]
COEFF_MATRIX[0][1][K]
COEFF_MATRIX[0][2][K]
.
.
.
COEFF_MATRIX[1][0][K]
COEFF_MATRIX[1][1][K]
COEFF_MATRIX[1][2][K]
.
.
.
#
The second line indicates whether the block contains data for 2-body
(:code:`2B`) or 3-body (:code:`3B`) interaction. This is followed by element
combination interaction, :code:`LEADING_TRIM` and :code:`TRAILING_TRIM`
number on the same line. The current implementation is only tested for
:code:`LEADING_TRIM=0` and :code:`TRAILING_TRIM=3`.
If other values are used LAMMPS is terminated after issuing an error message.
The :code:`Rij_CUTOFF` sets the 2-body cutoff for the interaction described
by the potential block. :code:`NUM_OF_KNOTS` is the number of knots
(or the length of the knot vector) present on the very next line. The
:code:`BSPLINE_KNOTS` line should contain all the knots in ascending order.
:code:`NUM_OF_COEFF` is the number of coefficients in the :code:`COEFF` line.
All the numbers in the BSPLINE_KNOTS and COEFF line should be space-separated.
Similar to the 2-body potential block, the third line sets the cutoffs and
length of the knots. The cutoff distance between atom-type I and J is
:code:`Rij_CUTOFF`, atom-type I and K is :code:`Rik_CUTOFF` and between
J and K is :code:`Rjk_CUTOFF`.
.. note::
The current implementation only works for UF3 potentials with cutoff
distances for 3-body interactions that follows
:code:`2Rij_CUTOFF=2Rik_CUTOFF=Rjk_CUTOFF` relation.
The :code:`BSPLINE_KNOTS_FOR_JK`, :code:`BSPLINE_KNOTS_FOR_IK`, and
:code:`BSPLINE_KNOTS_FOR_IJ` lines (note the order) contain the knots in
increasing order for atoms J and K, I and K, and atoms I and J
respectively. The number of knots is defined by the
:code:`NUM_OF_KNOTS_*` characters in the previous line. The shape of
the coefficient matrix is defined on the
:code:`SHAPE_OF_COEFF_MATRIX[I][J][K]` line followed by the columns of
the coefficient matrix, one per line, as shown above. For example, if
the coefficient matrix has the shape of 8x8x13, then
:code:`SHAPE_OF_COEFF_MATRIX[I][J][K]` will be :code:`8 8 13` followed
by 64 (8x8) lines each containing 13 coefficients separated by space.
----------
.. include:: accel_styles.rst
----------
Mixing, shift, table, tail correction, restart, rRESPA info
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
For atom type pairs I,J and I != J, where types I and J correspond to
two different element types, mixing is performed by LAMMPS as described
above from values in the potential file.
This pair style does not support the :doc:`pair_modify <pair_modify>`
shift, table, and tail options.
This pair style does not write its information to :doc:`binary restart
files <restart>`, since it is stored in potential file.
This pair style can only be used via the *pair* keyword of the
:doc:`run_style respa <run_style>` command. It does not support the
*inner*, *middle*, *outer* keywords.
Restrictions
""""""""""""
The 'uf3' pair style is part of the ML-UF3 package. It is only enabled
if LAMMPS was built with that package. See the :doc:`Build package
<Build_package>` page for more info.
This pair style requires the :doc:`newton <newton>` setting to be "on".
The UF3 LAMMPS potential file provided with LAMMPS (see the potentials
directory) are parameterized for metal :doc:`units <units>`.
The single() function of 'uf3' pair style only return the 2-body
interaction energy.
Related commands
""""""""""""""""
:doc:`pair_coeff <pair_coeff>`
Default
"""""""
none
----------
.. _Xie23:
**(Xie23)** Xie, S.R., Rupp, M. & Hennig, R.G. Ultra-fast interpretable machine-learning potentials. npj Comput Mater 9, 162 (2023). https://doi.org/10.1038/s41524-023-01092-7

View File

@ -8,56 +8,118 @@ Syntax
.. code-block:: LAMMPS .. code-block:: LAMMPS
replicate nx ny nz *keyword* replicate nx ny nz keyword ...
nx,ny,nz = replication factors in each dimension nx,ny,nz = replication factors in each dimension
* optional *keyword* = *bbox* * zero or more keywords may be appended
* keyword = *bbox* or *bond/periodic*
.. parsed-literal:: .. parsed-literal::
*bbox* = only check atoms in replicas that overlap with a processor's subdomain *bbox* = use a bounding-box algorithm which is faster for large proc counts
*bond/periodic* = use an algorithm that correctly replicates periodic bond loops
Examples Examples
"""""""" """"""""
For examples of replicating simple linear polymer chains (periodic or
non-periodic) or periodic carbon nanotubes, see examples/replicate.
.. code-block:: LAMMPS .. code-block:: LAMMPS
replicate 2 3 2 replicate 2 3 2
replicate 2 3 2 bbox
replicate 2 3 2 bond/periodic
Description Description
""""""""""" """""""""""
Replicate the current simulation one or more times in each dimension. Replicate the current system one or more times in each dimension. For
For example, replication factors of 2,2,2 will create a simulation example, replication factors of 2,2,2 will create a simulation with 8x
with 8x as many atoms by doubling the simulation domain in each as many atoms by doubling the size of the simulation box in each
dimension. A replication factor of 1 in a dimension leaves the dimension. A replication factor of 1 leaves the simulation domain
simulation domain unchanged. When the new simulation box is created unchanged in that dimension.
it is also partitioned into a regular 3d grid of rectangular bricks,
one per processor, based on the number of processors being used and
the settings of the :doc:`processors <processors>` command. The
partitioning can later be changed by the :doc:`balance <balance>` or
:doc:`fix balance <fix_balance>` commands.
All properties of the atoms are replicated, including their When the new simulation box is created it is partitioned into a
velocities, which may or may not be desirable. New atom IDs are regular 3d grid of rectangular bricks, one per processor, based on the
assigned to new atoms, as are molecule IDs. Bonds and other topology number of processors being used and the settings of the
interactions are created between pairs of new atoms as well as between :doc:`processors <processors>` command. The partitioning can be
old and new atoms. This is done by using the image flag for each atom changed by subsequent :doc:`balance <balance>` or :doc:`fix balance
to "unwrap" it out of the periodic box before replicating it. <fix_balance>` commands.
This means that any molecular bond you specify in the original data All properties of each atom are replicated (except per-atom fix data,
file that crosses a periodic boundary should be between two atoms with see the Restrictions section below). This includes their velocities,
image flags that differ by 1. This will allow the bond to be which may or may not be desirable. New atom IDs are assigned to new
unwrapped appropriately. atoms, as are new molecule IDs. Bonds and other topology interactions
are created between pairs of new atoms as well as between old and new
atoms.
The optional keyword *bbox* uses a bounding box to only check atoms in .. note::
replicas that overlap with a processor's subdomain when assigning
atoms to processors. It typically results in a substantial speedup The bond discussion which follows only refers to models with
when using the replicate command on a large number of processors. It permanent covalent bonds typically defined in LAMMPS via a data
does require temporary use of more memory, specifically that each file. It is not relevant to systems modeled with many-body
processor can store all atoms in the entire system before it is potentials which can define bonds on-the-fly, based on the current
replicated. positions of nearby atoms, e.g. models using the :doc:`AIREBO
<pair_airebo>` or :doc:`ReaxFF <pair_reaxff>` potentials.
If the *bond/periodic* keyword is not specified, bond replication is
done by using the image flag for each atom to "unwrap" it out of the
periodic box before replicating it. After replication is performed,
atoms outside the new periodic box are wrapped back into it. This
assigns correct images flags to all atoms in the system. For this to
work, all original atoms in the original simulation box must have
consistent image flags. This means that if two atoms have a bond
between them which crosses a periodic boundary, their respective image
flags will differ by 1 in that dimension.
Image flag consistency is not possible if a system has a periodic bond
loop, meaning there is a chain of bonds which crosses an entire
dimension and re-connects to itself across a periodic boundary. In
this case you MUST use the *bond/periodic* keyword to correctly
replicate the system. This option zeroes the image flags for all
atoms and uses a different algorithm to find new (nearby) bond
neighbors in the replicated system. In the final replicated system
all image flags are zero (in each dimension).
.. note::
LAMMPS does not check for image flag consistency before performing
the replication (it does issue a warning about this before a
simulation is run). If the original image flags are inconsistent,
the replicated system will also have inconsistent image flags, but
will otherwise be correctly replicated. This is NOT the case if
there is a periodic bond loop. See the next note.
.. note::
LAMMPS does not check for periodic bond loops. If you use the
*bond/periodic* keyword for a system without periodic bond loops,
the system will be correctly replicated, but image flag information
will be lost (which may or may not be important to your model). If
you do not use the *bond/periodic* keyword for a system with
periodic bond loops, the replicated system will have invalid bonds
(typically very long), resulting in bad dynamics.
If possible, the *bbox* keyword should be used when running on a large
number of processors, as it can result in a substantial speed-up for
the replication operation. It uses a bounding box to only check atoms
in replicas that overlap with each processor's new subdomain when
assigning atoms to processors. It also preserves image flag
information. The only drawback to the *bbox* option is that it
requires a temporary use of more memory. Each processor must be able
to store all atoms (and their per-atom data) in the original system,
before it is replicated.
.. note::
The algorithm used by the *bond/periodic* keyword builds on the
algorithm used by the *bbox* keyword and thus has the same memory
requirements. If you specify only the *bond/peridoic* keyword it
will internally set the *bbox* keyword as well.
----------
Restrictions Restrictions
"""""""""""" """"""""""""
@ -65,49 +127,30 @@ Restrictions
A 2d simulation cannot be replicated in the z dimension. A 2d simulation cannot be replicated in the z dimension.
If a simulation is non-periodic in a dimension, care should be used If a simulation is non-periodic in a dimension, care should be used
when replicating it in that dimension, as it may put atoms nearly on when replicating it in that dimension, as it may generate atoms nearly
top of each other. on top of each other.
.. note::
You cannot use the replicate command on a system which has a
molecule that spans the box and is bonded to itself across a periodic
boundary, so that the molecule is effectively a loop. A simple
example would be a linear polymer chain that spans the simulation box
and bonds back to itself across the periodic boundary. More realistic
examples would be a CNT (meant to be an infinitely long CNT) or a
graphene sheet or a bulk periodic crystal where there are explicit
bonds specified between near neighbors. (Note that this only applies
to systems that have permanent bonds as specified in the data file. A
CNT that is just atoms modeled with the :doc:`AIREBO potential <pair_airebo>` has no such permanent bonds, so it can be
replicated.) The reason replication does not work with those systems
is that the image flag settings described above cannot be made
consistent. I.e. it is not possible to define images flags so that
when every pair of bonded atoms is unwrapped (using the image flags),
they will be close to each other. The only way the replicate command
could work in this scenario is for it to break a bond, insert more
atoms, and re-connect the loop for the larger simulation box. But it
is not clever enough to do this. So you will have to construct a
larger version of your molecule as a pre-processing step and input a
new data file to LAMMPS.
If the current simulation was read in from a restart file (before a If the current simulation was read in from a restart file (before a
run is performed), there must not be any fix information stored in run is performed), there must not be any fix information stored in the
the file for individual atoms. Similarly, no fixes can be defined at file for individual atoms. Similarly, no fixes can be defined at the
the time the replicate command is used that require vectors of atom time the replicate command is used that require vectors of atom
information to be stored. This is because the replicate command does information to be stored. This is because the replicate command does
not know how to replicate that information for new atoms it creates. not know how to replicate that information for new atoms it creates.
To work around this restriction, restart files may be converted into
data files and fixes may be undefined via the :doc:`unfix <unfix>` To work around this restriction two options are possible. (1) Fixes
command before and redefined after the replicate command. which use the stored data in the restart file can be defined before
replication and then deleted via the :doc:`unfix <unfix>` command and
re-defined after it. Or (2) the restart file can be converted to a
data file (which deletes the stored fix information) and fixes defined
after the replicate command. In both these scenarios, the per-atom
fix information in the restart file is lost.
Related commands Related commands
"""""""""""""""" """"""""""""""""
none none
Default Default
""""""" """""""
none No settings for using the *bbox* or *bond/periodic* algorithms.

View File

@ -329,8 +329,10 @@ Restrictions
The *verlet/split* style can only be used if LAMMPS was built with the The *verlet/split* style can only be used if LAMMPS was built with the
REPLICA package. Correspondingly the *respa/omp* style is available REPLICA package. Correspondingly the *respa/omp* style is available
only if the OPENMP package was included. See the :doc:`Build package only if the OPENMP package was included. See the :doc:`Build package
<Build_package>` page for more info. It is not compatible with <Build_package>` page for more info.
kspace styles from the INTEL package.
Run style *verlet/split* is not compatible with kspace styles from
the INTEL package and it is not compatible with any TIP4P styles.
Whenever using rRESPA, the user should experiment with trade-offs in Whenever using rRESPA, the user should experiment with trade-offs in
speed and accuracy for their system, and verify that they are speed and accuracy for their system, and verify that they are

View File

@ -67,7 +67,7 @@ Syntax
bound(group,dir,region), gyration(group,region), ke(group,reigon), bound(group,dir,region), gyration(group,region), ke(group,reigon),
angmom(group,dim,region), torque(group,dim,region), angmom(group,dim,region), torque(group,dim,region),
inertia(group,dimdim,region), omega(group,dim,region) inertia(group,dimdim,region), omega(group,dim,region)
special functions = sum(x), min(x), max(x), ave(x), trap(x), slope(x), gmask(x), rmask(x), grmask(x,y), next(x), is_file(name), is_os(name), extract_setting(name), label2type(kind,label), is_typelabel(kind,label) special functions = sum(x), min(x), max(x), ave(x), trap(x), slope(x), sort(x), rsort(x), gmask(x), rmask(x), grmask(x,y), next(x), is_file(name), is_os(name), extract_setting(name), label2type(kind,label), is_typelabel(kind,label), is_timeout()
feature functions = is_available(category,feature), is_active(category,feature), is_defined(category,id) feature functions = is_available(category,feature), is_active(category,feature), is_defined(category,id)
atom value = id[i], mass[i], type[i], mol[i], x[i], y[i], z[i], vx[i], vy[i], vz[i], fx[i], fy[i], fz[i], q[i] atom value = id[i], mass[i], type[i], mol[i], x[i], y[i], z[i], vx[i], vy[i], vz[i], fx[i], fy[i], fz[i], q[i]
atom vector = id, mass, type, mol, radius, q, x, y, z, vx, vy, vz, fx, fy, fz atom vector = id, mass, type, mol, radius, q, x, y, z, vx, vy, vz, fx, fy, fz
@ -547,7 +547,7 @@ variables.
+------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Region functions | count(ID,IDR), mass(ID,IDR), charge(ID,IDR), xcm(ID,dim,IDR), vcm(ID,dim,IDR), fcm(ID,dim,IDR), bound(ID,dir,IDR), gyration(ID,IDR), ke(ID,IDR), angmom(ID,dim,IDR), torque(ID,dim,IDR), inertia(ID,dimdim,IDR), omega(ID,dim,IDR) | | Region functions | count(ID,IDR), mass(ID,IDR), charge(ID,IDR), xcm(ID,dim,IDR), vcm(ID,dim,IDR), fcm(ID,dim,IDR), bound(ID,dir,IDR), gyration(ID,IDR), ke(ID,IDR), angmom(ID,dim,IDR), torque(ID,dim,IDR), inertia(ID,dimdim,IDR), omega(ID,dim,IDR) |
+------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Special functions | sum(x), min(x), max(x), ave(x), trap(x), slope(x), gmask(x), rmask(x), grmask(x,y), next(x), is_file(name), is_os(name), extract_setting(name), label2type(kind,label), is_typelabel(kind,label) | | Special functions | sum(x), min(x), max(x), ave(x), trap(x), slope(x), sort(x), rsort(x), gmask(x), rmask(x), grmask(x,y), next(x), is_file(name), is_os(name), extract_setting(name), label2type(kind,label), is_typelabel(kind,label), is_timeout() |
+------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Feature functions | is_available(category,feature), is_active(category,feature), is_defined(category,id) | | Feature functions | is_available(category,feature), is_active(category,feature), is_defined(category,id) |
+------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
@ -913,23 +913,27 @@ Special Functions
Special functions take specific kinds of arguments, meaning their Special functions take specific kinds of arguments, meaning their
arguments cannot be formulas themselves. arguments cannot be formulas themselves.
The sum(x), min(x), max(x), ave(x), trap(x), and slope(x) functions The sum(x), min(x), max(x), ave(x), trap(x), slope(x), sort(x), and
each take 1 argument which is of the form "c_ID" or "c_ID[N]" or rsort(x) functions each take 1 argument which is of the form "c_ID" or
"f_ID" or "f_ID[N]" or "v_name". The first two are computes and the "c_ID[N]" or "f_ID" or "f_ID[N]" or "v_name". The first two are
second two are fixes; the ID in the reference should be replaced by computes and the second two are fixes; the ID in the reference should be
the ID of a compute or fix defined elsewhere in the input script. The replaced by the ID of a compute or fix defined elsewhere in the input
compute or fix must produce either a global vector or array. If it script. The compute or fix must produce either a global vector or
produces a global vector, then the notation without "[N]" should be array. If it produces a global vector, then the notation without "[N]"
used. If it produces a global array, then the notation with "[N]" should be used. If it produces a global array, then the notation with
should be used, when N is an integer, to specify which column of the "[N]" should be used, where N is an integer, to specify which column of
global array is being referenced. The last form of argument "v_name" the global array is being referenced. The last form of argument
is for a vector-style variable where "name" is replaced by the name of "v_name" is for a vector-style variable where "name" is replaced by the
the variable. name of the variable.
These functions operate on a global vector of inputs and reduce it to The sum(x), min(x), max(x), ave(x), trap(x), and slope(x) functions
a single scalar value. This is analogous to the operation of the operate on a global vector of inputs and reduce it to a single scalar
:doc:`compute reduce <compute_reduce>` command, which performs similar value. This is analogous to the operation of the :doc:`compute reduce
operations on per-atom and local vectors. <compute_reduce>` command, which performs similar operations on per-atom
and local vectors.
The sort(x) and rsort(x) functions operate on a global vector of inputs
and return a global vector of the same length.
The sum() function calculates the sum of all the vector elements. The The sum() function calculates the sum of all the vector elements. The
min() and max() functions find the minimum and maximum element min() and max() functions find the minimum and maximum element
@ -953,6 +957,12 @@ of points, equally spaced by 1 in their x coordinate: (1,V1), (2,V2),
length N. The returned value is the slope of the line. If the line length N. The returned value is the slope of the line. If the line
has a single point or is vertical, it returns 1.0e20. has a single point or is vertical, it returns 1.0e20.
.. versionadded:: 27June2024
The sort(x) and rsort(x) functions sort the data of the input vector by
their numeric value: sort(x) sorts in ascending order, rsort(x) sorts
in descending order.
The gmask(x) function takes 1 argument which is a group ID. It The gmask(x) function takes 1 argument which is a group ID. It
can only be used in atom-style variables. It returns a 1 for can only be used in atom-style variables. It returns a 1 for
atoms that are in the group, and a 0 for atoms that are not. atoms that are in the group, and a 0 for atoms that are not.
@ -1032,6 +1042,20 @@ label2type(), but returns 1 if the type label has been assigned,
otherwise it returns 0. This function can be used to check if a otherwise it returns 0. This function can be used to check if a
particular type label already exists in the simulation. particular type label already exists in the simulation.
.. versionadded:: TBD
The is_timeout() function returns 1 when the :doc:`timer timeout
<timer>` has expired otherwise it returns 0. This function can be used
to check inputs in combination with the :doc:`if command <if>` to
execute commands after the timer has expired. Example:
.. code-block:: LAMMPS
variable timeout equal is_timeout()
timer timeout 0:10:00 every 10
run 10000
if ${timeout} then "print 'Timer has expired'"
---------- ----------
Feature Functions Feature Functions

View File

@ -12,14 +12,14 @@ Syntax
* file = name of data file to write out * file = name of data file to write out
* zero or more keyword/value pairs may be appended * zero or more keyword/value pairs may be appended
* keyword = *pair* or *nocoeff* or *nofix* or *nolabelmap* * keyword = *nocoeff* or *nofix* or *nolabelmap* or *triclinic/general* or *types* or *pair*
.. parsed-literal:: .. parsed-literal::
*nocoeff* = do not write out force field info *nocoeff* = do not write out force field info
*nofix* = do not write out extra sections read by fixes *nofix* = do not write out extra sections read by fixes
*nolabelmap* = do not write out type labels *nolabelmap* = do not write out type labels
*triclinic/general = write data file in general triclinic format *triclinic/general* = write data file in general triclinic format
*types* value = *numeric* or *labels* *types* value = *numeric* or *labels*
*pair* value = *ii* or *ij* *pair* value = *ii* or *ij*
*ii* = write one line of pair coefficient info per atom type *ii* = write one line of pair coefficient info per atom type
@ -189,4 +189,4 @@ Related commands
Default Default
""""""" """""""
The option defaults are pair = ii and types_style = numeric. The option defaults are pair = ii and types = numeric.

View File

@ -1,6 +1,7 @@
Sphinx >= 5.3.0, <7.3 Sphinx >= 5.3.0, <8.0
sphinxcontrib-spelling sphinxcontrib-spelling
sphinxcontrib-jquery sphinxcontrib-jquery
sphinx-design
git+https://github.com/akohlmey/sphinx-fortran@parallel-read git+https://github.com/akohlmey/sphinx-fortran@parallel-read
sphinx-tabs>=3.4.1 sphinx-tabs>=3.4.1
breathe breathe

View File

@ -57,6 +57,7 @@ extensions = [
'table_from_list', 'table_from_list',
'tab_or_note', 'tab_or_note',
'breathe', 'breathe',
'sphinx_design'
] ]
images_config = { images_config = {

View File

@ -992,6 +992,7 @@ emax
Emax Emax
Embt Embt
emi emi
Emilie
Emmrich Emmrich
emol emol
eN eN
@ -1172,6 +1173,7 @@ finitecutflag
Finnis Finnis
Fiorin Fiorin
fitpod fitpod
fivebody
fixID fixID
fj fj
Fji Fji
@ -1433,6 +1435,7 @@ Hendrik
Henin Henin
Henkelman Henkelman
Henkes Henkes
Hennig
henrich henrich
Henrich Henrich
Hermitian Hermitian
@ -1594,6 +1597,7 @@ interlayer
intermolecular intermolecular
interoperable interoperable
Interparticle Interparticle
interpretable
interstitials interstitials
intertube intertube
Intr Intr
@ -1732,6 +1736,7 @@ Kalia
Kamberaj Kamberaj
Kantorovich Kantorovich
Kapfer Kapfer
Kapil
Karhunen Karhunen
Karls Karls
Karlsruhe Karlsruhe
@ -1763,8 +1768,10 @@ keflag
Keir Keir
Kelchner Kelchner
Kelkar Kelkar
Kemppainen
Kemper Kemper
kepler kepler
Kemppainen
keV keV
Keyes Keyes
keyfile keyfile
@ -1813,6 +1820,7 @@ Koziol
Kp Kp
kradius kradius
Kraker Kraker
Krass
Kraus Kraus
Kremer Kremer
Kress Kress
@ -2483,6 +2491,7 @@ Nevery
newfile newfile
Newns Newns
newtype newtype
nextsort
Neyts Neyts
Nf Nf
nfft nfft
@ -2672,6 +2681,7 @@ nzlo
ocl ocl
octahedral octahedral
octants octants
Odegard
Ohara Ohara
O'Hearn O'Hearn
ohenrich ohenrich
@ -2888,6 +2898,7 @@ Pmolrotate
Pmoltrans Pmoltrans
pN pN
png png
podd
Podhorszki Podhorszki
Poiseuille Poiseuille
poisson poisson
@ -2953,6 +2964,7 @@ Priya
proc proc
Proc Proc
procs procs
procgrid
progguide progguide
Prony Prony
ps ps
@ -3252,6 +3264,7 @@ rRESPA
Rsi Rsi
Rso Rso
Rspace Rspace
rsort
rsq rsq
rst rst
rstyle rstyle
@ -3264,6 +3277,7 @@ Rudranarayan
Rudzinski Rudzinski
Runge Runge
runtime runtime
Rupp
Rutuparna Rutuparna
rx rx
rxd rxd
@ -3287,6 +3301,7 @@ Saidi
saip saip
Salanne Salanne
Salles Salles
sametag
sandia sandia
Sandia Sandia
sandybrown sandybrown
@ -3357,6 +3372,7 @@ setmask
Setmask Setmask
setpoint setpoint
setvel setvel
sevenbody
sfftw sfftw
sfree sfree
Sg Sg
@ -3404,8 +3420,10 @@ sinh
sinusoid sinusoid
sinusoidally sinusoidally
SiO SiO
Siochi
Sirk Sirk
Sival Sival
sixbody
sizeI sizeI
sizeJ sizeJ
sizex sizex
@ -3451,6 +3469,7 @@ solvated
solvation solvation
someuser someuser
Sorensen Sorensen
sortfreq
soundspeed soundspeed
sourceforge sourceforge
Souza Souza
@ -3720,7 +3739,6 @@ tokyo
tol tol
tomic tomic
toolchain toolchain
toolset
topologies topologies
Toporov Toporov
Torder Torder
@ -3798,6 +3816,7 @@ typeJ
typelabel typelabel
typeN typeN
typesafe typesafe
typestr
Tz Tz
Tzou Tzou
ub ub
@ -3810,6 +3829,8 @@ uChem
uCond uCond
uef uef
UEF UEF
uf
uf3
ufm ufm
Uhlenbeck Uhlenbeck
Ui Ui
@ -4149,6 +4170,7 @@ yy
yz yz
Zagaceta Zagaceta
Zannoni Zannoni
Zavada
Zavattieri Zavattieri
zbl zbl
ZBL ZBL
@ -4162,6 +4184,7 @@ zenodo
Zepeda Zepeda
zflag zflag
Zhang Zhang
Zhao
Zhen Zhen
zhi zhi
Zhigilei Zhigilei

View File

@ -101,6 +101,7 @@ liblammpsplugin_t *liblammpsplugin_load(const char *lib)
ADDSYM(extract_setting); ADDSYM(extract_setting);
ADDSYM(extract_global_datatype); ADDSYM(extract_global_datatype);
ADDSYM(extract_global); ADDSYM(extract_global);
ADDSYM(map_atom);
ADDSYM(extract_atom_datatype); ADDSYM(extract_atom_datatype);
ADDSYM(extract_atom); ADDSYM(extract_atom);

View File

@ -146,6 +146,7 @@ struct _liblammpsplugin {
int (*extract_setting)(void *, const char *); int (*extract_setting)(void *, const char *);
int *(*extract_global_datatype)(void *, const char *); int *(*extract_global_datatype)(void *, const char *);
void *(*extract_global)(void *, const char *); void *(*extract_global)(void *, const char *);
void *(*map_atom)(void *, const void *);
int *(*extract_atom_datatype)(void *, const char *); int *(*extract_atom_datatype)(void *, const char *);
void *(*extract_atom)(void *, const char *); void *(*extract_atom)(void *, const char *);

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