Update from master

.gitattributes

@@ -1,3 +1,5 @@
 .gitattributes export-ignore
 .gitignore export-ignore
 .github export-ignore
+.lgtm.yml export-ignore
+SECURITY.md export-ignore

.github/CODEOWNERS

@@ -13,29 +13,38 @@ lib/kim/*             @ellio167
 lib/mesont/*          @iafoss
 
 # whole packages
-src/COMPRESS/*        @akohlmey
+src/COMPRESS/*        @rbberger
 src/GPU/*             @ndtrung81
 src/KOKKOS/*          @stanmoore1
 src/KIM/*             @ellio167
 src/LATTE/*           @cnegre
 src/MESSAGE/*         @sjplimp
+src/MLIAP/*           @athomps
+src/SNAP/*            @athomps
 src/SPIN/*            @julient31
+src/USER-BROWNIAN/*   @samueljmcameron
 src/USER-CGDNA/*      @ohenrich
 src/USER-CGSDK/*      @akohlmey
 src/USER-COLVARS/*    @giacomofiorin
+src/USER-DIELECTRIC/* @ndtrung81
+src/USER-FEP/*        @agiliopadua
+src/USER-HDNNP/*      @singraber
 src/USER-INTEL/*      @wmbrownintel
 src/USER-MANIFOLD/*   @Pakketeretet2
+src/USER-MDI/*        @taylor-a-barnes
 src/USER-MEAMC/*      @martok
 src/USER-MESONT/*     @iafoss
 src/USER-MOFFF/*      @hheenen
 src/USER-MOLFILE/*    @akohlmey
 src/USER-NETCDF/*     @pastewka
+src/USER-PACE/*       @yury-lysogorskiy
 src/USER-PLUMED/*     @gtribello
 src/USER-PHONON/*     @lingtikong
 src/USER-PTM/*        @pmla
 src/USER-OMP/*        @akohlmey
 src/USER-QMMM/*       @akohlmey
 src/USER-REAXC/*      @hasanmetin
+src/USER-REACTION/*   @jrgissing
 src/USER-SCAFACOS/*   @rhalver
 src/USER-TALLY/*      @akohlmey
 src/USER-UEF/*        @danicholson
@@ -47,7 +56,6 @@ src/GPU/pair_vashishta_gpu.*        @andeplane
 src/KOKKOS/pair_vashishta_kokkos.*  @andeplane
 src/MANYBODY/pair_vashishta_table.* @andeplane
 src/MANYBODY/pair_atm.*             @sergeylishchuk
-src/USER-REACTION/fix_bond_react.*  @jrgissing
 src/USER-MISC/*_grem.*              @dstelter92
 src/USER-MISC/compute_stress_mop*.* @RomainVermorel
 
@@ -122,6 +130,8 @@ tools/emacs/*         @HaoZeke
 tools/singularity/*   @akohlmey @rbberger
 tools/code_standard/* @rbberger
 tools/valgrind/*      @akohlmey
+tools/swig/*          @akohlmey
+tools/offline/*       @rbberger
 
 # tests
 unittest/*            @akohlmey @rbberger
@@ -130,7 +140,7 @@ unittest/*            @akohlmey @rbberger
 cmake/*               @junghans @rbberger
 cmake/Modules/Packages/USER-COLVARS.cmake @junghans @rbberger @giacomofiorin
 cmake/Modules/Packages/KIM.cmake @junghans @rbberger @ellio167
-cmake/presets/*.cmake @junghans @rbberger @akohlmey
+cmake/presets/*.cmake @akohlmey
 
 # python
 python/*              @rbberger
@@ -142,6 +152,7 @@ fortran/*             @akohlmey
 doc/utils/*/*         @rbberger
 doc/Makefile          @rbberger
 doc/README            @rbberger
+examples/plugin/*     @akohlmey
 
 # for releases
 src/version.h         @sjplimp

.github/CONTRIBUTING.md

@@ -26,11 +26,11 @@ __
 
 ## I don't want to read this whole thing I just have a question!
 
-> **Note:** Please do not file an issue to ask a general question about LAMMPS, its features, how to use specific commands, or how perform simulations or analysis in LAMMPS. Instead post your question to the ['lammps-users' mailing list](https://lammps.sandia.gov/mail.html). You do not need to be subscribed to post to the list (but a mailing list subscription avoids having your post delayed until it is approved by a mailing list moderator). Most posts to the mailing list receive a response within less than 24 hours. Before posting to the mailing list, please read the [mailing list guidelines](https://lammps.sandia.gov/guidelines.html). Following those guidelines will help greatly to get a helpful response. Always mention which LAMMPS version you are using.
+> **Note:** Please do not file an issue to ask a general question about LAMMPS, its features, how to use specific commands, or how perform simulations or analysis in LAMMPS. Instead post your question to either the ['lammps-users' mailing list](https://lammps.sandia.gov/mail.html) or the [LAMMPS Material Science Discourse forum](https://matsci.org/lammps). You do not need to be subscribed to post to the list (but a mailing list subscription avoids having your post delayed until it is approved by a mailing list moderator). Most posts to the mailing list receive a response within less than 24 hours. Before posting to the mailing list, please read the [mailing list guidelines](https://lammps.sandia.gov/guidelines.html). Following those guidelines will help greatly to get a helpful response. Always mention which LAMMPS version you are using. The LAMMPS forum was recently created as part of a larger effort to build a materials science community and have discussions not just about using LAMMPS. Thus the forum may be also used for discussions that would be off-topic for the mailing list. Those will just have to be moved to a more general category.
 
 ## How Can I Contribute?
 
-There are several ways how you can actively contribute to the LAMMPS project: you can discuss compiling and using LAMMPS, and solving LAMMPS related problems with other LAMMPS users on the lammps-users mailing list, you can report bugs or suggest enhancements by creating issues on GitHub (or posting them to the lammps-users mailing list), and you can contribute by submitting pull requests on GitHub or e-mail your code
+There are several ways how you can actively contribute to the LAMMPS project: you can discuss compiling and using LAMMPS, and solving LAMMPS related problems with other LAMMPS users on the lammps-users mailing list, you can report bugs or suggest enhancements by creating issues on GitHub (or posting them to the lammps-users mailing list or posting in the LAMMPS Materials Science Discourse forum), and you can contribute by submitting pull requests on GitHub or e-mail your code
 to one of the [LAMMPS core developers](https://lammps.sandia.gov/authors.html). As you may see from the aforementioned developer page, the LAMMPS software package includes the efforts of a very large number of contributors beyond the principal authors and maintainers.
 
 ### Discussing How To Use LAMMPS
@@ -42,6 +42,8 @@ Anyone can browse/search previous questions/answers in the archives. You do not
 
 If you post a message and you are a subscriber, your message will appear immediately. If you are not a subscriber, your message will be moderated, which typically takes one business day. Either way, when someone replies the reply will usually be sent to both, your personal email address and the mailing list. When replying to people, that responded to your post to the list, please always included the mailing list in your replies (i.e. use "Reply All" and **not** "Reply"). Responses will appear on the list in a few minutes, but it can take a few hours for postings and replies to show up in the SourceForge archive. Sending replies also to the mailing list is important, so that responses are archived and people with a similar issue can search for possible solutions in the mailing list archive.
 
+The LAMMPS Materials Science Discourse forum was created recently to facilitate discussion not just about LAMMPS and as part of a larger effort  towards building a materials science community. The forum contains a read-only sub-category with the continually updated mailing list archive, so you won't miss anything by joining only the forum and not the mailing list.
+
 ### Reporting Bugs
 
 While developers writing code for LAMMPS are careful to test their code, LAMMPS is such a large and complex software, that it is impossible to test for all combinations of features under all normal and not so normal circumstances. Thus bugs do happen, and if you suspect, that you have encountered one, please try to document it and report it as an [Issue](https://github.com/lammps/lammps/issues) on the LAMMPS GitHub project web page. However, before reporting a bug, you need to check whether this is something that may have already been corrected. The [Latest Features and Bug Fixes in LAMMPS](https://lammps.sandia.gov/bug.html) web page lists all significant changes to LAMMPS over the years. It also tells you what the current latest development version of LAMMPS is, and you should test whether your issue still applies to that version.
@@ -108,7 +110,7 @@ For bug reports, the next step is that one of the core LAMMPS developers will se
 
 For submitting pull requests, there is a [detailed tutorial](https://lammps.sandia.gov/doc/Howto_github.html) in the LAMMPS manual. Thus only a brief breakdown of the steps is presented here. Please note, that the LAMMPS developers are still reviewing and trying to improve the process. If you are unsure about something, do not hesitate to post a question on the lammps-users mailing list or contact one fo the core LAMMPS developers.
 Immediately after the submission, the LAMMPS continuing integration server at ci.lammps.org will download your submitted branch and perform a simple compilation test, i.e. will test whether your submitted code can be compiled under various conditions. It will also do a check on whether your included documentation translates cleanly. Whether these tests are successful or fail will be recorded. If a test fails, please inspect the corresponding output on the CI server and take the necessary steps, if needed, so that the code can compile cleanly again. The test will be re-run each the pull request is updated with a push to the remote branch on GitHub.
-Next a LAMMPS core developer will self-assign and do an overall technical assessment of the submission. If you are not yet registered as a LAMMPS collaborator, you will receive an invitation for that. As part of the assesment, the pull request will be categorized with labels. There are two special labels: `needs_work` (indicates that work from the submitter of the pull request is needed) and `work_in_progress` (indicates, that the assigned LAMMPS developer will make changes, if not done by the contributor who made the submit). 
+Next a LAMMPS core developer will self-assign and do an overall technical assessment of the submission. If you are not yet registered as a LAMMPS collaborator, you will receive an invitation for that. As part of the assessment, the pull request will be categorized with labels. There are two special labels: `needs_work` (indicates that work from the submitter of the pull request is needed) and `work_in_progress` (indicates, that the assigned LAMMPS developer will make changes, if not done by the contributor who made the submit). 
 You may also receive comments and suggestions on the overall submission or specific details and on occasion specific requests for changes as part of the review. If permitted, also additional changes may be pushed into your pull request branch or a pull request may be filed in your LAMMPS fork on GitHub to include those changes.
 The LAMMPS developer may then decide to assign the pull request to another developer (e.g. when that developer is more knowledgeable about the submitted feature or enhancement or has written the modified code). It may also happen, that additional developers are requested to provide a review and approve the changes. For submissions, that may change the general behavior of LAMMPS, or where a possibility of unwanted side effects exists, additional tests may be requested by the assigned developer.
 If the assigned developer is satisfied and considers the submission ready for inclusion into LAMMPS, the pull request will receive approvals and be merged into the master branch by one of the core LAMMPS developers. After the pull request is merged, you may delete the feature branch used for the pull request in your personal LAMMPS fork.

.github/codeql/cpp.yml

@@ -0,0 +1,4 @@
+paths:
+ - src
+ - lib
+ - tools

.github/codeql/python.yml

@@ -0,0 +1,5 @@
+paths:
+ - python/lammps
+
+queries:
+ - uses: security-and-quality

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,49 @@
+# GitHub action to run static code analysis on C++ and Python code
+name: "CodeQL Code Analysis"
+
+on:
+  push:
+    branches: [master]
+
+jobs:
+  analyze:
+    name: Analyze
+    if: ${{ github.repository == 'lammps/lammps' }}
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: ['cpp', 'python']
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+
+    - name: Setup Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        config-file: ./.github/codeql/${{ matrix.language }}.yml
+
+    - name: Create Build Environment
+      if: ${{ matrix.language == 'cpp' }}
+      run: mkdir build
+
+    - name: Building LAMMPS via CMake
+      if: ${{ matrix.language == 'cpp' }}
+      shell: bash
+      working-directory: build
+      run: |
+        cmake -C ../cmake/presets/most.cmake ../cmake
+        cmake --build . --parallel 2
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/unittest-macos.yml

@@ -0,0 +1,54 @@
+# GitHub action to build LAMMPS on MacOS and run unit tests
+name: "Unittest for MacOS"
+
+on:
+  push:
+    branches: [master]
+
+jobs:
+  build:
+    name: MacOS Unit Test
+    if: ${{ github.repository == 'lammps/lammps' }}
+    runs-on: macos-latest
+    env:
+      CCACHE_DIR: ${{ github.workspace }}/.ccache
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+
+    - name: Install ccache
+      run: brew install ccache
+
+    - name: Create Build Environment
+      run: mkdir build
+
+    - name: Set up ccache
+      uses: actions/cache@v2
+      with:
+        path: ${{ env.CCACHE_DIR }}
+        key: macos-ccache-${{ github.sha }}
+        restore-keys: macos-ccache-
+
+    - name: Building LAMMPS via CMake
+      shell: bash
+      working-directory: build
+      run: |
+        ccache -z
+        cmake -C ../cmake/presets/clang.cmake \
+              -C ../cmake/presets/most.cmake \
+              -D CMAKE_CXX_COMPILER_LAUNCHER=ccache \
+              -D CMAKE_C_COMPILER_LAUNCHER=ccache \
+              -D ENABLE_TESTING=on \
+              -D BUILD_SHARED_LIBS=on \
+              -D LAMMPS_EXCEPTIONS=on \
+              ../cmake
+        cmake --build . --parallel 2
+        ccache -s
+
+    - name: Run Tests
+      working-directory: build
+      shell: bash
+      run: ctest -V

.lgtm.yml

@@ -0,0 +1,14 @@
+extraction:
+  cpp:
+    configure:
+      command:
+      - "mkdir build"
+      - "cd build"
+      - "cmake -G Ninja -C ../cmake/presets/most.cmake ../cmake"
+    index:
+      build_command:
+      - "cd build"
+      - "ninja"
+  python:
+    python_setup:
+      version: 3

LICENSE

@@ -1,6 +1,6 @@
 GNU GENERAL PUBLIC LICENSE
 
-Version 2, June 1991 
+Version 2, June 1991
 
 Copyright (C) 1989, 1991 Free Software Foundation, Inc.  
 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
@@ -301,9 +301,8 @@ one line to give the program's name and an idea of what it does.
 Copyright (C) yyyy  name of author
 
 This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
+it under the terms of the GNU General Public License version 2 as
-the Free Software Foundation; either version 2 of the License, or (at
+published by the Free Software Foundation.
-your option) any later version.
 
 This program is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of

README

@@ -14,10 +14,10 @@ LAMMPS is a classical molecular dynamics simulation code designed to
 run efficiently on parallel computers.  It was developed at Sandia
 National Laboratories, a US Department of Energy facility, with
 funding from the DOE.  It is an open-source code, distributed freely
-under the terms of the GNU Public License (GPL).
+under the terms of the GNU Public License (GPL) version 2.
 
 The primary author of the code is Steve Plimpton, who can be emailed
-at sjplimp@sandia.gov.  The LAMMPS WWW Site at lammps.sandia.gov has
+at sjplimp@sandia.gov.  The LAMMPS WWW Site at www.lammps.org has
 more information about the code and its uses.
 
 The LAMMPS distribution includes the following files and directories:
@@ -37,14 +37,14 @@ tools                      pre- and post-processing tools
 
 Point your browser at any of these files to get started:
 
-https://lammps.sandia.gov/doc/Manual.html         LAMMPS user manual
+https://docs.lammps.org/Manual.html         LAMMPS manual
-https://lammps.sandia.gov/doc/Intro.html          hi-level introduction
+https://docs.lammps.org/Intro.html          hi-level introduction
-https://lammps.sandia.gov/doc/Build.html          how to build LAMMPS
+https://docs.lammps.org/Build.html          how to build LAMMPS
-https://lammps.sandia.gov/doc/Run_head.html       how to run LAMMPS
+https://docs.lammps.org/Run_head.html       how to run LAMMPS
-https://lammps.sandia.gov/doc/Commands_all.html   Table of available commands
+https://docs.lammps.org/Commands_all.html   Table of available commands
-https://lammps.sandia.gov/doc/pg_library.html     LAMMPS programmer guide
+https://docs.lammps.org/Library.html        LAMMPS library interfaces
-https://lammps.sandia.gov/doc/Modify.html         how to modify and extend LAMMPS
+https://docs.lammps.org/Modify.html         how to modify and extend LAMMPS
-https://lammps.sandia.gov/doc/pg_developer.html   LAMMPS developer guide
+https://docs.lammps.org/Developer.html      LAMMPS developer info
 
 You can also create these doc pages locally:
 

SECURITY.md

@@ -0,0 +1,35 @@
+# Security Policy
+
+LAMMPS is designed as a user-level application to conduct computer
+simulations for research using classical mechanics.  As such LAMMPS
+depends to some degrees on users providing correctly formatted input and
+LAMMPS needs to read and write files based on uncontrolled user input.
+As a parallel application for use in high-performance computing
+environments, performance critical steps are also done without checking
+data.
+
+LAMMPS also is interfaced to a number of external libraries, including
+libraries with experimental research software, that are not validated
+and tested by the LAMMPS developers, so it is easy to import bad
+behavior from calling functions in one of those libraries.
+
+Thus is is quite easy to crash LAMMPS through malicious input and do all
+kinds of filesystem manipulations.  And because of that LAMMPS should
+**NEVER** be compiled or **run** as superuser, either from a "root" or
+"administrator" account directly or indirectly via "sudo" or "su".
+
+Therefore what could be seen as a security vulnerability is usually
+either a user mistake or a bug in the code.  Bugs can be reported in
+the LAMMPS project
+[issue tracker on GitHub](https://github.com/lammps/lammps/issues).
+
+
+# Version Updates
+
+LAMMPS follows continuous release development model.  We aim to keep all
+release versions (stable or patch) fully functional and employ a variety
+of automatic testing procedures to detect failures of existing
+functionality from adding new features before releases are made.  Thus
+bugfixes and updates are only integrated into the current development
+branch and thus the next (patch) release and users are recommended to
+update regularly.

bench/POTENTIALS/README

@@ -1,7 +1,7 @@
 These are input scripts used to run benchmark tests for many of the
 interatomic potentials in LAMMPS.  The results of running these
 scripts on different machines are shown on the Potentials section of
-the Benchmark page of the LAMMPS WWW site (lammps.sandia.gov/bench).
+the Benchmark page of the LAMMPS WWW site (https://www.lammps.org/bench.html).
 
 Examples are shown below of how to run these scripts.  Log files for
 running them on 1 and 4 processors of a Linux box are included in the

bench/README

@@ -2,7 +2,7 @@ LAMMPS benchmark problems
 
 This directory contains 5 benchmark problems which are discussed in
 the Benchmark section of the LAMMPS documentation, and on the
-Benchmark page of the LAMMPS WWW site (lammps.sandia.gov/bench).
+Benchmark page of the LAMMPS WWW site (https://www.lammps.org/bench.html).
 
 This directory also has several sub-directories:
 
@@ -11,7 +11,7 @@ KEPLER          benchmark scripts for GPU cluster with Kepler GPUs
 POTENTIALS      benchmarks scripts for various potentials in LAMMPS
 
 The results for all of these benchmarks are displayed and discussed on
-the Benchmark page of the LAMMPS WWW site: lammps.sandia.gov/bench.
+the Benchmark page of the LAMMPS WWW site: https://www.lammps.org/bench.html
 
 The remainder of this file refers to the 5 problems in the top-level
 of this directory and how to run them on CPUs, either in serial or

cmake/CMakeLists.txt

@@ -7,6 +7,11 @@ cmake_minimum_required(VERSION 3.10)
 if(POLICY CMP0074)
   cmake_policy(SET CMP0074 NEW)
 endif()
+# set policy to silence warnings about missing executable permissions in
+# pythonx.y-config when cross-compiling. review occasionally if it may be set to NEW
+if(POLICY CMP0109)
+  cmake_policy(SET CMP0109 OLD)
+endif()
 ########################################
 
 project(lammps CXX)
@@ -22,18 +27,30 @@ set(LAMMPS_TOOLS_DIR      ${LAMMPS_DIR}/tools)
 set(LAMMPS_PYTHON_DIR     ${LAMMPS_DIR}/python)
 set(LAMMPS_POTENTIALS_DIR ${LAMMPS_DIR}/potentials)
 
+set(LAMMPS_DOWNLOADS_URL "https://download.lammps.org" CACHE STRING "Base URL for LAMMPS downloads")
+set(LAMMPS_POTENTIALS_URL "${LAMMPS_DOWNLOADS_URL}/potentials")
+set(LAMMPS_THIRDPARTY_URL "${LAMMPS_DOWNLOADS_URL}/thirdparty")
+mark_as_advanced(LAMMPS_DOWNLOADS_URL)
+
 find_package(Git)
 
 # by default, install into $HOME/.local (not /usr/local), so that no root access (and sudo!!) is needed
-if (CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
-  set(CMAKE_INSTALL_PREFIX "$ENV{HOME}/.local" CACHE PATH "default install path" FORCE )
+  set(CMAKE_INSTALL_PREFIX "$ENV{HOME}/.local" CACHE PATH "Default install path" FORCE)
+endif()
+
+# If enabled, no need to use LD_LIBRARY_PATH / DYLD_LIBRARY_PATH when installed
+option(LAMMPS_INSTALL_RPATH "Set runtime path for shared libraries linked to LAMMPS binaries" OFF)
+if(LAMMPS_INSTALL_RPATH)
+  set(CMAKE_INSTALL_RPATH ${CMAKE_INSTALL_FULL_LIBDIR})
+  set(CMAKE_INSTALL_RPATH_USE_LINK_PATH ON)
 endif()
 
 # Cmake modules/macros are in a subdirectory to keep this file cleaner
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/Modules)
 
 # make sure LIBRARY_PATH is set if environment variable is set
-if (DEFINED ENV{LIBRARY_PATH})
+if(DEFINED ENV{LIBRARY_PATH})
   list(APPEND CMAKE_LIBRARY_PATH "$ENV{LIBRARY_PATH}")
   message(STATUS "Appending $ENV{LIBRARY_PATH} to CMAKE_LIBRARY_PATH: ${CMAKE_LIBRARY_PATH}")
 endif()
@@ -60,7 +77,7 @@ check_for_autogen_files(${LAMMPS_SOURCE_DIR})
 include(CheckIncludeFileCXX)
 
 # set required compiler flags and compiler/CPU arch specific optimizations
-if(${CMAKE_CXX_COMPILER_ID} STREQUAL "Intel")
+if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -restrict")
   if(CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 17.3 OR CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 17.4)
     set(CMAKE_TUNE_DEFAULT "-xCOMMON-AVX512")
@@ -74,6 +91,11 @@ set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF CACHE BOOL "Use compiler extensions")
 
+# export all symbols when building a .dll file on windows
+if((CMAKE_SYSTEM_NAME STREQUAL "Windows") AND BUILD_SHARED_LIBS)
+  set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+endif()
+
 ########################################################################
 # User input options                                                   #
 ########################################################################
@@ -92,11 +114,23 @@ endif()
 option(BUILD_TOOLS "Build and install LAMMPS tools (msi2lmp, binary2txt, chain)" OFF)
 option(BUILD_LAMMPS_SHELL "Build and install the LAMMPS shell" OFF)
 
+# allow enabling clang-tidy for C++ files
+set(ENABLE_CLANG_TIDY OFF CACHE BOOL "Include clang-tidy processing when compiling")
+if(ENABLE_CLANG_TIDY)
+  set(CMAKE_CXX_CLANG_TIDY "clang-tidy;-checks=*-header-filter=.*" CACHE STRING "")
+endif()
+
 include(GNUInstallDirs)
 file(GLOB ALL_SOURCES ${LAMMPS_SOURCE_DIR}/[^.]*.cpp)
 file(GLOB MAIN_SOURCES ${LAMMPS_SOURCE_DIR}/main.cpp)
 list(REMOVE_ITEM ALL_SOURCES ${MAIN_SOURCES})
 add_library(lammps ${ALL_SOURCES})
+
+# tell CMake to export all symbols to a .dll on Windows with MinGW cross-compilers
+if(BUILD_SHARED_LIBS AND (CMAKE_SYSTEM_NAME STREQUAL "Windows") AND CMAKE_CROSSCOMPILING)
+  set_target_properties(lammps PROPERTIES LINK_FLAGS "-Wl,--export-all-symbols")
+endif()
+
 add_executable(lmp ${MAIN_SOURCES})
 target_link_libraries(lmp PRIVATE lammps)
 set_target_properties(lmp PROPERTIES OUTPUT_NAME ${LAMMPS_BINARY})
@@ -106,14 +140,16 @@ option(CMAKE_VERBOSE_MAKEFILE "Generate verbose Makefiles" OFF)
 
 set(STANDARD_PACKAGES ASPHERE BODY CLASS2 COLLOID COMPRESS DIPOLE
   GRANULAR KSPACE LATTE MANYBODY MC MESSAGE MISC MLIAP MOLECULE PERI POEMS
-  QEQ REPLICA RIGID SHOCK SPIN SNAP SRD KIM PYTHON MSCG MPIIO VORONOI
+  PLUGIN QEQ REPLICA RIGID SHOCK SPIN SNAP SRD KIM PYTHON MSCG MPIIO VORONOI
-  USER-ATC USER-AWPMD USER-BOCS USER-CGDNA USER-MESODPD USER-CGSDK USER-COLVARS
+  USER-ADIOS USER-ATC USER-AWPMD USER-BOCS USER-CGDNA USER-MESODPD USER-CGSDK
-  USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP USER-H5MD USER-LB
+  USER-COLVARS USER-DIELECTRIC USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP
-  USER-MANIFOLD USER-MEAMC USER-MESONT USER-MGPT USER-MISC USER-MOFFF USER-MOLFILE
+  USER-H5MD USER-HDNNP USER-LB USER-MANIFOLD USER-MDI USER-MEAMC USER-MESONT USER-MGPT
-  USER-NETCDF USER-PHONON USER-PLUMED USER-PTM USER-QTB USER-REACTION
+  USER-MISC USER-MOFFF USER-MOLFILE USER-NETCDF USER-PHONON USER-PLUMED USER-PTM USER-QTB
-  USER-REAXC USER-SCAFACOS USER-SDPD USER-SMD USER-SMTBQ USER-SPH USER-TALLY
+  USER-RANN USER-REACTION USER-REAXC USER-SCAFACOS USER-SDPD USER-SMD USER-SMTBQ USER-SPH
-  USER-UEF USER-VTK USER-QUIP USER-QMMM USER-YAFF USER-ADIOS)
+  USER-TALLY USER-UEF USER-VTK USER-QUIP USER-QMMM USER-YAFF USER-PACE USER-BROWNIAN)
-set(SUFFIX_PACKAGES CORESHELL USER-OMP KOKKOS OPT USER-INTEL GPU)
+
+set(SUFFIX_PACKAGES CORESHELL GPU KOKKOS OPT USER-INTEL USER-OMP)
+
 foreach(PKG ${STANDARD_PACKAGES} ${SUFFIX_PACKAGES})
   option(PKG_${PKG} "Build ${PKG} Package" OFF)
 endforeach()
@@ -137,12 +173,13 @@ if(NOT CMAKE_CROSSCOMPILING)
   find_package(MPI QUIET)
   option(BUILD_MPI "Build MPI version" ${MPI_FOUND})
 else()
+  set(MPI_CXX_SKIP_MPICXX TRUE)
   option(BUILD_MPI "Build MPI version" OFF)
 endif()
 
 if(BUILD_MPI)
   # We use a non-standard procedure to cross-compile with MPI on Windows
-  if((CMAKE_SYSTEM_NAME STREQUAL Windows) AND CMAKE_CROSSCOMPILING)
+  if((CMAKE_SYSTEM_NAME STREQUAL "Windows") AND CMAKE_CROSSCOMPILING)
     include(MPI4WIN)
     target_link_libraries(lammps PUBLIC MPI::MPI_CXX)
   else()
@@ -154,8 +191,7 @@ if(BUILD_MPI)
     endif()
   endif()
 else()
-  enable_language(C)
+  file(GLOB MPI_SOURCES ${LAMMPS_SOURCE_DIR}/STUBS/mpi.cpp)
-  file(GLOB MPI_SOURCES ${LAMMPS_SOURCE_DIR}/STUBS/mpi.c)
   add_library(mpi_stubs STATIC ${MPI_SOURCES})
   set_target_properties(mpi_stubs PROPERTIES OUTPUT_NAME lammps_mpi_stubs${LAMMPS_MACHINE})
   target_include_directories(mpi_stubs PUBLIC $<BUILD_INTERFACE:${LAMMPS_SOURCE_DIR}/STUBS>)
@@ -177,7 +213,7 @@ string(TOUPPER ${LAMMPS_SIZES} LAMMPS_SIZES)
 target_compile_definitions(lammps PUBLIC -DLAMMPS_${LAMMPS_SIZES})
 
 # posix_memalign is not available on Windows
-if(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
+if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
   set(LAMMPS_MEMALIGN "0" CACHE STRING "posix_memalign() is not available on Windows" FORCE)
 else()
   set(LAMMPS_MEMALIGN "64" CACHE STRING "enables the use of the posix_memalign() call instead of malloc() when large chunks or memory are allocated by LAMMPS. Set to 0 to disable")
@@ -199,6 +235,7 @@ pkg_depends(USER-ATC MANYBODY)
 pkg_depends(USER-LB MPI)
 pkg_depends(USER-PHONON KSPACE)
 pkg_depends(USER-SCAFACOS MPI)
+pkg_depends(USER-DIELECTRIC KSPACE)
 
 # detect if we may enable OpenMP support by default
 set(BUILD_OMP_DEFAULT OFF)
@@ -219,7 +256,10 @@ if(BUILD_OMP)
     message(FATAL_ERROR "Cannot find the 'omp.h' header file required for full OpenMP support")
   endif()
 
-  if (((CMAKE_CXX_COMPILER_ID STREQUAL "GNU") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 9.0)) OR
+  if(((CMAKE_CXX_COMPILER_ID STREQUAL "GNU") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 9.0)) OR
+      (CMAKE_CXX_COMPILER_ID STREQUAL "PGI") OR (CMAKE_CXX_COMPILER_ID STREQUAL "NVHPC") OR
+      (CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM") OR (CMAKE_CXX_COMPILER_ID STREQUAL "XLClang") OR
+      ((CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 10.0)) OR
       ((CMAKE_CXX_COMPILER_ID STREQUAL "Clang") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 10.0)) OR
       ((CMAKE_CXX_COMPILER_ID STREQUAL "Intel") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 19.0)))
     # GCC 9.x and later plus Clang 10.x and later implement strict OpenMP 4.0 semantics for consts.
@@ -231,68 +271,6 @@ if(BUILD_OMP)
   target_link_libraries(lammps PRIVATE OpenMP::OpenMP_CXX)
 endif()
 
-# Compiler specific features for testing
-if(${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU")
-  option(ENABLE_COVERAGE "Enable collecting code coverage data" OFF)
-  mark_as_advanced(ENABLE_COVERAGE)
-  if(ENABLE_COVERAGE)
-    if(CMAKE_VERSION VERSION_LESS 3.13)
-      if(CMAKE_CXX_FLAGS)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --coverage")
-      else()
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_${CMAKE_BUILD_TYPE}_FLAGS} --coverage")
-      endif()
-    else()
-      target_compile_options(lammps PUBLIC --coverage)
-      target_link_options(lammps PUBLIC --coverage)
-    endif()
-  endif()
-endif()
-
-#######################################
-# add custom target for IWYU analysis
-#######################################
-set(ENABLE_IWYU OFF CACHE BOOL "Add 'iwyu' build target to call the include-what-you-use tool")
-mark_as_advanced(ENABLE_IWYU)
-if(ENABLE_IWYU)
-  find_program(IWYU_EXE NAMES include-what-you-use iwyu)
-  find_program(IWYU_TOOL NAMES iwyu_tool iwyu-tool iwyu_tool.py)
-  if (IWYU_EXE AND IWYU_TOOL)
-    add_custom_target(
-      iwyu
-      ${IWYU_TOOL} -o clang -p ${CMAKE_CURRENT_BINARY_DIR} -- -Xiwyu --mapping_file=${CMAKE_CURRENT_SOURCE_DIR}/iwyu/iwyu-extra-map.imp
-      COMMENT "Running IWYU")
-    add_dependencies(iwyu lammps)
-  else()
-    message(FATAL_ERROR "To use IWYU you need the include-what-you-use/iwyu executable"
-      "and the iwyu-tool/iwyu_tool script installed in your PATH")
-  endif()
-endif()
-
-set(ENABLE_SANITIZER "none" CACHE STRING "Select a code sanitizer option (none (default), address, leak, thread, undefined)")
-mark_as_advanced(ENABLE_SANITIZER)
-set(ENABLE_SANITIZER_VALUES none address leak thread undefined)
-set_property(CACHE ENABLE_SANITIZER PROPERTY STRINGS ${ENABLE_SANITIZER_VALUES})
-validate_option(ENABLE_SANITIZER ENABLE_SANITIZER_VALUES)
-string(TOLOWER ${ENABLE_SANITIZER} ENABLE_SANITIZER)
-if(NOT ENABLE_SANITIZER STREQUAL "none")
-  if((${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU") OR (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang"))
-    if(CMAKE_VERSION VERSION_LESS 3.13)
-      if(CMAKE_CXX_FLAGS)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=${ENABLE_SANITIZER}")
-      else()
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_${CMAKE_BUILD_TYPE}_FLAGS} -fsanitize=${ENABLE_SANITIZER}")
-      endif()
-    else()
-      target_compile_options(lammps PUBLIC -fsanitize=${ENABLE_SANITIZER})
-      target_link_options(lammps PUBLIC -fsanitize=${ENABLE_SANITIZER})
-    endif()
-  else()
-    message(WARNING "ENABLE_SANITIZER option not supported by ${CMAKE_CXX_COMPILER_ID} compilers. Ignoring.")
-    set(ENABLE_SANITIZER "none")
-  endif()
-endif()
-
 if(PKG_MSCG OR PKG_USER-ATC OR PKG_USER-AWPMD OR PKG_USER-QUIP OR PKG_LATTE)
   enable_language(C)
   find_package(LAPACK)
@@ -344,7 +322,7 @@ find_program(GZIP_EXECUTABLE gzip)
 find_package_handle_standard_args(GZIP REQUIRED_VARS GZIP_EXECUTABLE)
 option(WITH_GZIP "Enable GZIP support" ${GZIP_FOUND})
 if(WITH_GZIP)
-  if(GZIP_FOUND OR ((CMAKE_SYSTEM_NAME STREQUAL Windows) AND CMAKE_CROSSCOMPILING))
+  if(GZIP_FOUND OR ((CMAKE_SYSTEM_NAME STREQUAL "Windows") AND CMAKE_CROSSCOMPILING))
     target_compile_definitions(lammps PRIVATE -DLAMMPS_GZIP)
   else()
     message(FATAL_ERROR "gzip executable not found")
@@ -355,7 +333,7 @@ find_program(FFMPEG_EXECUTABLE ffmpeg)
 find_package_handle_standard_args(FFMPEG REQUIRED_VARS FFMPEG_EXECUTABLE)
 option(WITH_FFMPEG "Enable FFMPEG support" ${FFMPEG_FOUND})
 if(WITH_FFMPEG)
-  if(FFMPEG_FOUND OR ((CMAKE_SYSTEM_NAME STREQUAL Windows) AND CMAKE_CROSSCOMPILING))
+  if(FFMPEG_FOUND OR ((CMAKE_SYSTEM_NAME STREQUAL "Windows") AND CMAKE_CROSSCOMPILING))
     target_compile_definitions(lammps PRIVATE -DLAMMPS_FFMPEG)
   else()
     message(FATAL_ERROR "ffmpeg executable not found")
@@ -372,8 +350,8 @@ else()
   set(CUDA_REQUEST_PIC)
 endif()
 
-foreach(PKG_WITH_INCL KSPACE PYTHON VORONOI USER-COLVARS USER-MOLFILE USER-NETCDF USER-PLUMED USER-QMMM
+foreach(PKG_WITH_INCL KSPACE PYTHON MLIAP VORONOI USER-COLVARS USER-HDNNP USER-MDI USER-MOLFILE USER-NETCDF
-        USER-QUIP USER-SCAFACOS USER-SMD USER-VTK KIM LATTE MESSAGE MSCG COMPRESS)
+        USER-PLUMED USER-QMMM USER-QUIP USER-SCAFACOS USER-SMD USER-VTK KIM LATTE MESSAGE MSCG COMPRESS USER-PACE)
   if(PKG_${PKG_WITH_INCL})
     include(Packages/${PKG_WITH_INCL})
   endif()
@@ -470,7 +448,7 @@ foreach(SIMPLE_LIB POEMS USER-ATC USER-AWPMD USER-H5MD USER-MESONT)
   if(PKG_${SIMPLE_LIB})
     string(REGEX REPLACE "^USER-" "" PKG_LIB "${SIMPLE_LIB}")
     string(TOLOWER "${PKG_LIB}" PKG_LIB)
-    if(PKG_LIB STREQUAL mesont)
+    if(PKG_LIB STREQUAL "mesont")
       enable_language(Fortran)
       file(GLOB_RECURSE ${PKG_LIB}_SOURCES
         ${LAMMPS_LIB_SOURCE_DIR}/${PKG_LIB}/[^.]*.f90)
@@ -482,9 +460,9 @@ foreach(SIMPLE_LIB POEMS USER-ATC USER-AWPMD USER-H5MD USER-MESONT)
     add_library(${PKG_LIB} STATIC ${${PKG_LIB}_SOURCES})
     set_target_properties(${PKG_LIB} PROPERTIES OUTPUT_NAME lammps_${PKG_LIB}${LAMMPS_MACHINE})
     target_link_libraries(lammps PRIVATE ${PKG_LIB})
-    if(PKG_LIB STREQUAL awpmd)
+    if(PKG_LIB STREQUAL "awpmd")
       target_include_directories(awpmd PUBLIC ${LAMMPS_LIB_SOURCE_DIR}/awpmd/systems/interact ${LAMMPS_LIB_SOURCE_DIR}/awpmd/ivutils/include)
-    elseif(PKG_LIB STREQUAL h5md)
+    elseif(PKG_LIB STREQUAL "h5md")
       target_include_directories(h5md PUBLIC ${LAMMPS_LIB_SOURCE_DIR}/h5md/include ${HDF5_INCLUDE_DIRS})
     else()
       target_include_directories(${PKG_LIB} PUBLIC ${LAMMPS_LIB_SOURCE_DIR}/${PKG_LIB})
@@ -497,7 +475,7 @@ if(PKG_USER-AWPMD)
 endif()
 
 if(PKG_USER-ATC)
-  if(LAMMPS_SIZES STREQUAL BIGBIG)
+  if(LAMMPS_SIZES STREQUAL "BIGBIG")
     message(FATAL_ERROR "The USER-ATC Package is not compatible with -DLAMMPS_BIGBIG")
   endif()
   target_link_libraries(atc PRIVATE ${LAPACK_LIBRARIES})
@@ -524,12 +502,24 @@ foreach(PKG_WITH_INCL CORESHELL QEQ USER-OMP USER-SDPD KOKKOS OPT USER-INTEL GPU
   endif()
 endforeach()
 
+if(PKG_PLUGIN)
+  if(BUILD_SHARED_LIBS)
+    target_compile_definitions(lammps PRIVATE -DLMP_PLUGIN)
+  else()
+    message(WARNING "Plugin loading will not work unless BUILD_SHARED_LIBS is enabled")
+  endif()
+  # link with -ldl or equivalent for plugin loading; except on Windows
+  if(NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
+    target_link_libraries(lammps PRIVATE ${CMAKE_DL_LIBS})
+  endif()
+endif()
+
 ######################################################################
 # the windows version of LAMMPS requires a couple extra libraries
 # and the MPI library - if use - has to be linked right before those
 # and after everything else that is compiled locally
 ######################################################################
-if(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
+if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
   target_link_libraries(lammps PRIVATE -lwsock32 -lpsapi)
 endif()
 
@@ -578,8 +568,8 @@ add_dependencies(lammps gitversion)
 # Actually add executable and lib to build
 ############################################
 get_property(LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
-list (FIND LANGUAGES "Fortran" _index)
+list(FIND LANGUAGES "Fortran" _index)
-if (${_index} GREATER -1)
+if(_index GREATER -1)
   target_link_libraries(lammps PRIVATE ${CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES})
 endif()
 set(LAMMPS_CXX_HEADERS angle.h atom.h bond.h citeme.h comm.h compute.h dihedral.h domain.h error.h fix.h force.h group.h improper.h
@@ -649,7 +639,7 @@ install(
 if(BUILD_SHARED_LIBS)
   if(CMAKE_VERSION VERSION_LESS 3.12)
     # adjust so we find Python 3 versions before Python 2 on old systems with old CMake
-    set(Python_ADDITIONAL_VERSIONS 3.8 3.7 3.6 3.5)
+    set(Python_ADDITIONAL_VERSIONS 3.9 3.8 3.7 3.6 3.5)
     find_package(PythonInterp) # Deprecated since version 3.12
     if(PYTHONINTERP_FOUND)
         set(Python_EXECUTABLE ${PYTHON_EXECUTABLE})
@@ -657,12 +647,12 @@ if(BUILD_SHARED_LIBS)
   else()
     find_package(Python COMPONENTS Interpreter)
   endif()
-  if (Python_EXECUTABLE)
+  if(Python_EXECUTABLE)
     add_custom_target(
-      install-python
+      install-python ${CMAKE_COMMAND} -E remove_directory build
-      ${Python_EXECUTABLE} install.py -v ${LAMMPS_SOURCE_DIR}/version.h
+      COMMAND ${Python_EXECUTABLE} install.py -v ${LAMMPS_SOURCE_DIR}/version.h
-      -m ${LAMMPS_PYTHON_DIR}/lammps.py
+      -p ${LAMMPS_PYTHON_DIR}/lammps
-      -l ${CMAKE_BINARY_DIR}/liblammps${CMAKE_SHARED_LIBRARY_SUFFIX}
+      -l ${CMAKE_BINARY_DIR}/liblammps${LAMMPS_MACHINE}${CMAKE_SHARED_LIBRARY_SUFFIX}
       WORKING_DIRECTORY  ${LAMMPS_PYTHON_DIR}
       COMMENT "Installing LAMMPS Python module")
   else()
@@ -690,12 +680,9 @@ if(BUILD_SHARED_LIBS OR PKG_PYTHON)
   else()
     find_package(Python COMPONENTS Interpreter)
   endif()
-  if (Python_EXECUTABLE)
+  if(Python_EXECUTABLE)
-    execute_process(COMMAND ${Python_EXECUTABLE}
+    file(MAKE_DIRECTORY ${CMAKE_BINARY_DIR}/python)
-      -c "import distutils.sysconfig as cg; print(cg.get_python_lib(1,0,prefix='${CMAKE_INSTALL_PREFIX}'))"
+    install(CODE "execute_process(COMMAND ${Python_EXECUTABLE} setup.py build -b ${CMAKE_BINARY_DIR}/python install --prefix=${CMAKE_INSTALL_PREFIX} --root=\$ENV{DESTDIR}/ WORKING_DIRECTORY ${LAMMPS_PYTHON_DIR})")
-      OUTPUT_VARIABLE PYTHON_DEFAULT_INSTDIR OUTPUT_STRIP_TRAILING_WHITESPACE)
-    set(PYTHON_INSTDIR ${PYTHON_DEFAULT_INSTDIR} CACHE PATH "Installation folder for LAMMPS Python module")
-    install(FILES ${LAMMPS_PYTHON_DIR}/lammps.py DESTINATION ${PYTHON_INSTDIR})
   endif()
 endif()
 
@@ -707,7 +694,7 @@ get_target_property(DEFINES lammps COMPILE_DEFINITIONS)
 include(FeatureSummary)
 feature_summary(DESCRIPTION "The following tools and libraries have been found and configured:" WHAT PACKAGES_FOUND)
 message(STATUS "<<< Build configuration >>>
-   Operating System: ${CMAKE_SYSTEM_NAME}
+   Operating System: ${CMAKE_SYSTEM_NAME} ${CMAKE_LINUX_DISTRO} ${CMAKE_DISTRO_VERSION}
    Build type:       ${CMAKE_BUILD_TYPE}
    Install path:     ${CMAKE_INSTALL_PREFIX}
    Generator:        ${CMAKE_GENERATOR} using ${CMAKE_MAKE_PROGRAM}")
@@ -738,15 +725,15 @@ if(OPTIONS)
   message("      Options:       ${OPTIONS}")
 endif()
 get_property(LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
-list (FIND LANGUAGES "Fortran" _index)
+list(FIND LANGUAGES "Fortran" _index)
-if (${_index} GREATER -1)
+if(_index GREATER -1)
   message(STATUS "Fortran Compiler: ${CMAKE_Fortran_COMPILER}
       Type:          ${CMAKE_Fortran_COMPILER_ID}
       Version:       ${CMAKE_Fortran_COMPILER_VERSION}
       Fortran Flags:${CMAKE_Fortran_FLAGS} ${CMAKE_Fortran_FLAGS_${BTYPE}}")
 endif()
-list (FIND LANGUAGES "C" _index)
+list(FIND LANGUAGES "C" _index)
-if (${_index} GREATER -1)
+if(_index GREATER -1)
   message(STATUS "C compiler:       ${CMAKE_C_COMPILER}
       Type:          ${CMAKE_C_COMPILER_ID}
       Version:       ${CMAKE_C_COMPILER_VERSION}
@@ -776,11 +763,12 @@ if(BUILD_MPI)
 endif()
 if(PKG_GPU)
   message(STATUS "<<< GPU package settings >>>
--- GPU API:          ${GPU_API}")
+-- GPU API:                  ${GPU_API}")
   if(GPU_API STREQUAL "CUDA")
-    message(STATUS "GPU architecture: ${GPU_ARCH}")
+    message(STATUS "CUDA Compiler:            ${CUDA_NVCC_EXECUTABLE}")
-  elseif(GPU_API STREQUAL "OPENCL")
+    message(STATUS "GPU default architecture: ${GPU_ARCH}")
-    message(STATUS "OpenCL tuning:    ${OCL_TUNE}")
+    message(STATUS "GPU binning with CUDPP:   ${CUDPP_OPT}")
+    message(STATUS "CUDA MPS support:         ${CUDA_MPS_SUPPORT}")
   elseif(GPU_API STREQUAL "HIP")
     message(STATUS "HIP platform:     ${HIP_PLATFORM}")
     message(STATUS "HIP architecture: ${HIP_ARCH}")
@@ -790,7 +778,7 @@ if(PKG_GPU)
       message(STATUS "HIP GPU sorting: off")
     endif()
   endif()
-  message(STATUS "GPU precision:    ${GPU_PREC}")
+  message(STATUS "GPU precision:            ${GPU_PREC}")
 endif()
 if(PKG_KOKKOS)
   message(STATUS "Kokkos Arch: ${KOKKOS_ARCH}")
@@ -810,7 +798,7 @@ if(PKG_KSPACE)
   endif()
   if(PKG_KOKKOS)
     if(Kokkos_ENABLE_CUDA)
-      if (${FFT} STREQUAL "KISS")
+      if(FFT STREQUAL "KISS")
         message(STATUS "Kokkos FFT: KISS")
       else()
         message(STATUS "Kokkos FFT: cuFFT")

cmake/Modules/CodingStandard.cmake

@@ -8,13 +8,18 @@ else()
     find_package(Python3 COMPONENTS Interpreter QUIET)
 endif()
 
-if (Python3_EXECUTABLE)
+if(Python3_EXECUTABLE)
     if(Python3_VERSION VERSION_GREATER_EQUAL 3.5)
         add_custom_target(
           check-whitespace
           ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/whitespace.py .
           WORKING_DIRECTORY  ${LAMMPS_DIR}
           COMMENT "Check for whitespace errors")
+        add_custom_target(
+          check-homepage
+          ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/homepage.py .
+          WORKING_DIRECTORY  ${LAMMPS_DIR}
+          COMMENT "Check for homepage URL errors")
         add_custom_target(
           check-permissions
           ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/permissions.py .
@@ -25,6 +30,11 @@ if (Python3_EXECUTABLE)
           ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/whitespace.py -f .
           WORKING_DIRECTORY  ${LAMMPS_DIR}
           COMMENT "Fix whitespace errors")
+        add_custom_target(
+          fix-homepage
+          ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/homepage.py -f .
+          WORKING_DIRECTORY  ${LAMMPS_DIR}
+          COMMENT "Fix homepage URL errors")
         add_custom_target(
           fix-permissions
           ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/permissions.py -f .

cmake/Modules/Documentation.cmake

@@ -50,16 +50,20 @@ if(BUILD_DOC)
     OUTPUT ${DOC_BUILD_DIR}/requirements.txt
     DEPENDS docenv ${DOCENV_REQUIREMENTS_FILE}
     COMMAND ${CMAKE_COMMAND} -E copy ${DOCENV_REQUIREMENTS_FILE} ${DOC_BUILD_DIR}/requirements.txt
-    COMMAND ${DOCENV_BINARY_DIR}/pip install --upgrade pip
+    COMMAND ${DOCENV_BINARY_DIR}/pip $ENV{PIP_OPTIONS} install --upgrade pip
-    COMMAND ${DOCENV_BINARY_DIR}/pip install --upgrade ${LAMMPS_DOC_DIR}/utils/converters
+    COMMAND ${DOCENV_BINARY_DIR}/pip $ENV{PIP_OPTIONS} install --upgrade ${LAMMPS_DOC_DIR}/utils/converters
-    COMMAND ${DOCENV_BINARY_DIR}/pip install --use-feature=2020-resolver -r ${DOC_BUILD_DIR}/requirements.txt --upgrade
+    COMMAND ${DOCENV_BINARY_DIR}/pip $ENV{PIP_OPTIONS} install -r ${DOC_BUILD_DIR}/requirements.txt --upgrade
   )
 
+  set(MATHJAX_URL "https://github.com/mathjax/MathJax/archive/3.1.3.tar.gz" CACHE STRING "URL for MathJax tarball")
+  set(MATHJAX_MD5 "d1c98c746888bfd52ca8ebc10704f92f" CACHE STRING "MD5 checksum of MathJax tarball")
+  mark_as_advanced(MATHJAX_URL)
+
   # download mathjax distribution and unpack to folder "mathjax"
   if(NOT EXISTS ${DOC_BUILD_STATIC_DIR}/mathjax/es5)
-    file(DOWNLOAD "https://github.com/mathjax/MathJax/archive/3.1.2.tar.gz"
+    file(DOWNLOAD ${MATHJAX_URL}
       "${CMAKE_CURRENT_BINARY_DIR}/mathjax.tar.gz"
-      EXPECTED_MD5 a4a6a093a89bc2ccab1452d766b98e53)
+      EXPECTED_MD5 ${MATHJAX_MD5})
     execute_process(COMMAND ${CMAKE_COMMAND} -E tar xzf mathjax.tar.gz WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
     file(GLOB MATHJAX_VERSION_DIR ${CMAKE_CURRENT_BINARY_DIR}/MathJax-*)
     execute_process(COMMAND ${CMAKE_COMMAND} -E rename ${MATHJAX_VERSION_DIR} ${DOC_BUILD_STATIC_DIR}/mathjax)

cmake/Modules/FindCythonize.cmake

@@ -0,0 +1,30 @@
+# Find the Cythonize tool.
+#
+# This code sets the following variables:
+#
+#  Cythonize_EXECUTABLE
+#
+# adapted from https://github.com/cmarshall108/cython-cmake-example/blob/master/cmake/FindCython.cmake
+#=============================================================================
+
+if(CMAKE_VERSION VERSION_LESS 3.12)
+    find_package(PythonInterp 3.6 QUIET) # Deprecated since version 3.12
+    if(PYTHONINTERP_FOUND)
+        set(Python3_EXECUTABLE ${PYTHON_EXECUTABLE})
+    endif()
+else()
+    find_package(Python3 3.6 COMPONENTS Interpreter QUIET)
+endif()
+
+# Use the Cython executable that lives next to the Python executable
+# if it is a local installation.
+if(Python3_EXECUTABLE)
+  get_filename_component(_python_path ${Python3_EXECUTABLE} PATH)
+  find_program(Cythonize_EXECUTABLE
+    NAMES cythonize3 cythonize cythonize.bat
+    HINTS ${_python_path})
+endif()
+
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(Cythonize REQUIRED_VARS Cythonize_EXECUTABLE)
+mark_as_advanced(Cythonize_EXECUTABLE)

cmake/Modules/FindN2P2.cmake

@@ -0,0 +1,61 @@
+include(FindPackageHandleStandardArgs)
+
+# Check if N2P2_DIR is set manually.
+if (DEFINED ENV{N2P2_DIR})
+  set(N2P2_DIR "${N2P2_DIR}")
+# If not, try if directory "lib/hdnnp/n2p2" exists.
+else()
+  get_filename_component(_fullpath "${LAMMPS_LIB_SOURCE_DIR}/hdnnp/n2p2" REALPATH)
+  if (EXISTS ${_fullpath})
+    set(N2P2_DIR "${_fullpath}")
+  endif()
+endif()
+
+# Set path to include directory.
+find_path(N2P2_INCLUDE_DIR InterfaceLammps.h HINTS "${N2P2_DIR}/include")
+# Two libraries need to be linked: libnnp and libnnpif.
+find_library(N2P2_LIBNNP NAMES nnp HINTS "${N2P2_DIR}/lib")
+find_library(N2P2_LIBNNPIF NAMES nnpif HINTS "${N2P2_DIR}/lib")
+# Users could compile n2p2 with extra flags which are then also required for
+# pair_hdnnp.cpp compilation. To forward them to the LAMMPS build process n2p2
+# writes a file with cmake commands, e.g.
+#
+# target_compile_definitions(lammps PRIVATE -DN2P2_NO_SF_GROUPS)
+#
+# to "lib/lammps-extra.cmake" which is then included by USER-HDNNP.cmake.
+find_file(N2P2_CMAKE_EXTRA NAMES lammps-extra.cmake HINTS "${N2P2_DIR}/lib")
+
+find_package_handle_standard_args(N2P2 DEFAULT_MSG
+  N2P2_DIR
+  N2P2_INCLUDE_DIR
+  N2P2_LIBNNP
+  N2P2_LIBNNPIF
+  N2P2_CMAKE_EXTRA)
+
+if(N2P2_FOUND)
+  if (NOT TARGET N2P2::N2P2)
+    # n2p2 core library "libnnp"
+    add_library(N2P2::LIBNNP UNKNOWN IMPORTED)
+    set_target_properties(N2P2::LIBNNP PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES ${N2P2_INCLUDE_DIR}
+      IMPORTED_LOCATION ${N2P2_LIBNNP})
+    # n2p2 interface library "libnnpif"
+    add_library(N2P2::LIBNNPIF UNKNOWN IMPORTED)
+    set_target_properties(N2P2::LIBNNPIF PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES ${N2P2_INCLUDE_DIR}
+      IMPORTED_LOCATION ${N2P2_LIBNNPIF})
+    # Put libnnp, libnnpif and include directory together.
+    add_library(N2P2::N2P2 INTERFACE IMPORTED)
+    set_property(TARGET N2P2::N2P2 PROPERTY
+      INTERFACE_LINK_LIBRARIES N2P2::LIBNNPIF N2P2::LIBNNP)
+    set(N2P2_CMAKE_EXTRAS ${N2P2_CMAKE_EXTRA})
+  endif()
+endif()
+
+mark_as_advanced(
+  N2P2_DIR
+  N2P2_INCLUDE_DIR
+  N2P2_LIBNNP
+  N2P2_LIBNNPIF
+  N2P2_CMAKE_EXTRA
+)

cmake/Modules/GTest.cmake

@@ -1,6 +1,6 @@
 message(STATUS "Downloading and building Google Test library")
 
-if(CMAKE_BUILD_TYPE STREQUAL Debug)
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
   set(GTEST_LIB_POSTFIX d)
 else()
   set(GTEST_LIB_POSTFIX)
@@ -8,10 +8,12 @@ endif()
 
 include(ExternalProject)
 set(GTEST_URL "https://github.com/google/googletest/archive/release-1.10.0.tar.gz" CACHE STRING "URL for GTest tarball")
+set(GTEST_MD5 "ecd1fa65e7de707cd5c00bdac56022cd" CACHE STRING "MD5 checksum of GTest tarball")
 mark_as_advanced(GTEST_URL)
+mark_as_advanced(GTEST_MD5)
 ExternalProject_Add(googletest
-                    URL ${GTEST_URL}
+                    URL             ${GTEST_URL}
-                    URL_MD5         ecd1fa65e7de707cd5c00bdac56022cd
+                    URL_MD5         ${GTEST_MD5}
                     SOURCE_DIR      "${CMAKE_BINARY_DIR}/gtest-src"
                     BINARY_DIR      "${CMAKE_BINARY_DIR}/gtest-build"
                     CMAKE_ARGS      ${CMAKE_REQUEST_PIC} ${CMAKE_EXTRA_GTEST_OPTS}
@@ -20,10 +22,10 @@ ExternalProject_Add(googletest
                                     -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
                                     -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
                                     -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
-                    BUILD_BYPRODUCTS <BINARY_DIR>/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${GTEST_LIB_POSTFIX}.a
+                    BUILD_BYPRODUCTS <BINARY_DIR>/lib/libgtest${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX}
-                                     <BINARY_DIR>/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gmock${GTEST_LIB_POSTFIX}.a
+                                     <BINARY_DIR>/lib/libgmock${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX}
-                                     <BINARY_DIR>/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gtest_main${GTEST_LIB_POSTFIX}.a
+                                     <BINARY_DIR>/lib/libgtest_main${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX}
-                                     <BINARY_DIR>/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gmock_main${GTEST_LIB_POSTFIX}.a
+                                     <BINARY_DIR>/lib/libgmock_main${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX}
                     LOG_DOWNLOAD ON
                     LOG_CONFIGURE ON
                     LOG_BUILD ON
@@ -39,10 +41,10 @@ file(MAKE_DIRECTORY ${GTEST_INCLUDE_DIR})
 file(MAKE_DIRECTORY ${GMOCK_INCLUDE_DIR})
 
 ExternalProject_Get_Property(googletest BINARY_DIR)
-set(GTEST_LIBRARY_PATH ${BINARY_DIR}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${GTEST_LIB_POSTFIX}.a)
+set(GTEST_LIBRARY_PATH ${BINARY_DIR}/lib/libgtest${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX})
-set(GMOCK_LIBRARY_PATH ${BINARY_DIR}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gmock${GTEST_LIB_POSTFIX}.a)
+set(GMOCK_LIBRARY_PATH ${BINARY_DIR}/lib/libgmock${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX})
-set(GTEST_MAIN_LIBRARY_PATH ${BINARY_DIR}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gtest_main${GTEST_LIB_POSTFIX}.a)
+set(GTEST_MAIN_LIBRARY_PATH ${BINARY_DIR}/lib/libgtest_main${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX})
-set(GMOCK_MAIN_LIBRARY_PATH ${BINARY_DIR}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gmock_main${GTEST_LIB_POSTFIX}.a)
+set(GMOCK_MAIN_LIBRARY_PATH ${BINARY_DIR}/lib/libgmock_main${GTEST_LIB_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX})
 
 # Prevent GoogleTest from overriding our compiler/linker options
 # when building with Visual Studio

cmake/Modules/GenerateOpenCLHeader.cmake

@@ -0,0 +1,3 @@
+# utility script to call WriteOpenCLHeader function
+include(${SOURCE_DIR}/Modules/OpenCLUtils.cmake)
+WriteOpenCLHeader(${VARNAME} ${HEADER_FILE} ${SOURCE_FILES})

cmake/Modules/LAMMPSUtils.cmake

@@ -50,6 +50,7 @@ function(check_for_autogen_files source_dir)
     file(GLOB SRC_AUTOGEN_FILES ${source_dir}/style_*.h)
     file(GLOB SRC_AUTOGEN_PACKAGES ${source_dir}/packages_*.h)
     list(APPEND SRC_AUTOGEN_FILES ${SRC_AUTOGEN_PACKAGES} ${source_dir}/lmpinstalledpkgs.h ${source_dir}/lmpgitversion.h)
+    list(APPEND SRC_AUTOGEN_FILES ${SRC_AUTOGEN_PACKAGES} ${source_dir}/mliap_model_python_couple.h ${source_dir}/mliap_model_python_couple.cpp)
     foreach(_SRC ${SRC_AUTOGEN_FILES})
       get_filename_component(FILENAME "${_SRC}" NAME)
       if(EXISTS ${source_dir}/${FILENAME})
@@ -85,7 +86,6 @@ endfunction(GenerateBinaryHeader)
 # fetch missing potential files
 function(FetchPotentials pkgfolder potfolder)
   if (EXISTS "${pkgfolder}/potentials.txt")
-    set(LAMMPS_POTENTIALS_URL "https://download.lammps.org/potentials")
     file(STRINGS "${pkgfolder}/potentials.txt" linelist REGEX "^[^#].")
     foreach(line ${linelist})
       string(FIND ${line} " " blank)
@@ -104,3 +104,13 @@ function(FetchPotentials pkgfolder potfolder)
     endforeach()
   endif()
 endfunction(FetchPotentials)
+
+# set CMAKE_LINUX_DISTRO and CMAKE_DISTRO_VERSION on Linux
+if((CMAKE_SYSTEM_NAME STREQUAL "Linux") AND (EXISTS /etc/os-release))
+  file(STRINGS /etc/os-release distro REGEX "^NAME=")
+  string(REGEX REPLACE "NAME=\"?([^\"]*)\"?" "\\1" distro "${distro}")
+  file(STRINGS /etc/os-release disversion REGEX "^VERSION_ID=")
+  string(REGEX REPLACE "VERSION_ID=\"?([^\"]*)\"?" "\\1" disversion "${disversion}")
+  set(CMAKE_LINUX_DISTRO ${distro})
+  set(CMAKE_DISTRO_VERSION ${disversion})
+endif()

cmake/Modules/MPI4WIN.cmake

@@ -1,16 +1,25 @@
 # Download and configure custom MPICH files for Windows
 message(STATUS "Downloading and configuring MPICH-1.4.1 for Windows")
+set(MPICH2_WIN64_DEVEL_URL "${LAMMPS_THIRDPARTY_URL}/mpich2-win64-devel.tar.gz" CACHE STRING "URL for MPICH2 (win64) tarball")
+set(MPICH2_WIN32_DEVEL_URL "${LAMMPS_THIRDPARTY_URL}/mpich2-win32-devel.tar.gz" CACHE STRING "URL for MPICH2 (win32) tarball")
+set(MPICH2_WIN64_DEVEL_MD5 "4939fdb59d13182fd5dd65211e469f14" CACHE STRING "MD5 checksum of MPICH2 (win64) tarball")
+set(MPICH2_WIN32_DEVEL_MD5 "a61d153500dce44e21b755ee7257e031" CACHE STRING "MD5 checksum of MPICH2 (win32) tarball")
+mark_as_advanced(MPICH2_WIN64_DEVEL_URL)
+mark_as_advanced(MPICH2_WIN32_DEVEL_URL)
+mark_as_advanced(MPICH2_WIN64_DEVEL_MD5)
+mark_as_advanced(MPICH2_WIN32_DEVEL_MD5)
+
 include(ExternalProject)
-if (CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+if(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
   ExternalProject_Add(mpi4win_build
-    URL https://download.lammps.org/thirdparty/mpich2-win64-devel.tar.gz
+    URL     ${MPICH2_WIN64_DEVEL_URL}
-    URL_MD5 4939fdb59d13182fd5dd65211e469f14
+    URL_MD5 ${MPICH2_WIN64_DEVEL_MD5}
     CONFIGURE_COMMAND "" BUILD_COMMAND "" INSTALL_COMMAND ""
     BUILD_BYPRODUCTS <SOURCE_DIR>/lib/libmpi.a)
 else()
   ExternalProject_Add(mpi4win_build
-    URL https://download.lammps.org/thirdparty/mpich2-win32-devel.tar.gz
+    URL     ${MPICH2_WIN32_DEVEL_URL}
-    URL_MD5 a61d153500dce44e21b755ee7257e031
+    URL_MD5 ${MPICH2_WIN32_DEVEL_MD5}
     CONFIGURE_COMMAND "" BUILD_COMMAND "" INSTALL_COMMAND ""
     BUILD_BYPRODUCTS <SOURCE_DIR>/lib/libmpi.a)
 endif()

cmake/Modules/OpenCLLoader.cmake

@@ -0,0 +1,50 @@
+message(STATUS "Downloading and building OpenCL loader library")
+set(OPENCL_LOADER_URL "${LAMMPS_THIRDPARTY_URL}/opencl-loader-2021.05.02.tar.gz" CACHE STRING "URL for OpenCL loader tarball")
+set(OPENCL_LOADER_MD5 "29180b05056578afda92f0d394c3a373" CACHE STRING "MD5 checksum of OpenCL loader tarball")
+mark_as_advanced(OPENCL_LOADER_URL)
+mark_as_advanced(OPENCL_LOADER_MD5)
+
+include(ExternalProject)
+ExternalProject_Add(opencl_loader
+                    URL             ${OPENCL_LOADER_URL}
+                    URL_MD5         ${OPENCL_LOADER_MD5}
+                    SOURCE_DIR      "${CMAKE_BINARY_DIR}/opencl_loader-src"
+                    BINARY_DIR      "${CMAKE_BINARY_DIR}/opencl_loader-build"
+                    CMAKE_ARGS      ${CMAKE_REQUEST_PIC} ${CMAKE_EXTRA_OPENCL_LOADER_OPTS}
+                                    -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+                                    -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
+                                    -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+                                    -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
+                                    -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
+                    BUILD_BYPRODUCTS <BINARY_DIR>/libOpenCL${CMAKE_STATIC_LIBRARY_SUFFIX}
+                    LOG_DOWNLOAD ON
+                    LOG_CONFIGURE ON
+                    LOG_BUILD ON
+                    INSTALL_COMMAND ""
+                    TEST_COMMAND    "")
+
+ExternalProject_Get_Property(opencl_loader SOURCE_DIR)
+set(OPENCL_LOADER_INCLUDE_DIR ${SOURCE_DIR}/inc)
+
+# workaround for CMake 3.10 on ubuntu 18.04
+file(MAKE_DIRECTORY ${OPENCL_LOADER_INCLUDE_DIR})
+
+ExternalProject_Get_Property(opencl_loader BINARY_DIR)
+set(OPENCL_LOADER_LIBRARY_PATH "${BINARY_DIR}/libOpenCL${CMAKE_STATIC_LIBRARY_SUFFIX}")
+
+find_package(Threads QUIET)
+if(NOT WIN32)
+  set(OPENCL_LOADER_DEP_LIBS "Threads::Threads;${CMAKE_DL_LIBS}")
+else()
+  set(OPENCL_LOADER_DEP_LIBS "cfgmgr32;runtimeobject")
+endif()
+
+add_library(OpenCL::OpenCL UNKNOWN IMPORTED)
+add_dependencies(OpenCL::OpenCL opencl_loader)
+
+set_target_properties(OpenCL::OpenCL PROPERTIES
+  IMPORTED_LOCATION ${OPENCL_LOADER_LIBRARY_PATH}
+  INTERFACE_INCLUDE_DIRECTORIES ${OPENCL_LOADER_INCLUDE_DIR}
+  INTERFACE_LINK_LIBRARIES "${OPENCL_LOADER_DEP_LIBS}")
+
+

cmake/Modules/OpenCLUtils.cmake

@@ -1,10 +1,8 @@
-function(GenerateOpenCLHeader varname outfile files)
+function(WriteOpenCLHeader varname outfile files)
-    message("Creating ${outfile}...")
     file(WRITE ${outfile} "const char * ${varname} = \n")
-    math(EXPR ARG_END   "${ARGC}-1")
+    separate_arguments(files)
 
-    foreach(IDX RANGE 2 ${ARG_END})
+    foreach(filename ${files})
-        list(GET ARGV ${IDX} filename)
         file(READ ${filename} content)
         string(REGEX REPLACE "\\s*//[^\n]*\n" "\n" content "${content}")
         string(REGEX REPLACE "\\\\" "\\\\\\\\" content "${content}")
@@ -15,4 +13,16 @@ function(GenerateOpenCLHeader varname outfile files)
     endforeach()
 
     file(APPEND ${outfile} ";\n")
+endfunction(WriteOpenCLHeader)
+
+function(GenerateOpenCLHeader varname outfile files)
+    list(REMOVE_AT ARGV 0 1)
+    add_custom_command(OUTPUT ${outfile}
+      COMMAND ${CMAKE_COMMAND} -D SOURCE_DIR=${CMAKE_CURRENT_SOURCE_DIR}
+                               -D VARNAME=${varname}
+                               -D HEADER_FILE=${outfile}
+                               -D SOURCE_FILES="${ARGV}"
+                               -P ${CMAKE_CURRENT_SOURCE_DIR}/Modules/GenerateOpenCLHeader.cmake
+      DEPENDS ${ARGV}
+      COMMENT "Generating ${outfile}...")
 endfunction(GenerateOpenCLHeader)

cmake/Modules/Packages/GPU.cmake

@@ -1,7 +1,10 @@
 set(GPU_SOURCES_DIR ${LAMMPS_SOURCE_DIR}/GPU)
 set(GPU_SOURCES ${GPU_SOURCES_DIR}/gpu_extra.h
                 ${GPU_SOURCES_DIR}/fix_gpu.h
-                ${GPU_SOURCES_DIR}/fix_gpu.cpp)
+                ${GPU_SOURCES_DIR}/fix_gpu.cpp
+                ${GPU_SOURCES_DIR}/fix_nh_gpu.h
+                ${GPU_SOURCES_DIR}/fix_nh_gpu.cpp)
+target_compile_definitions(lammps PRIVATE -DLMP_GPU)
 
 set(GPU_API "opencl" CACHE STRING "API used by GPU package")
 set(GPU_API_VALUES opencl cuda hip)
@@ -32,9 +35,12 @@ if(GPU_API STREQUAL "CUDA")
   if(NOT BIN2C)
     message(FATAL_ERROR "Could not find bin2c, use -DBIN2C=/path/to/bin2c to help cmake finding it.")
   endif()
-  option(CUDPP_OPT "Enable CUDPP_OPT" ON)
+  option(CUDPP_OPT "Enable GPU binning via CUDAPP (should be off for modern GPUs)" OFF)
   option(CUDA_MPS_SUPPORT "Enable tweaks to support CUDA Multi-process service (MPS)" OFF)
   if(CUDA_MPS_SUPPORT)
+    if(CUDPP_OPT)
+      message(FATAL_ERROR "Must use -DCUDPP_OPT=OFF with -DGPU_CUDA_MPS_SUPPORT=ON")
+    endif()
     set(GPU_CUDA_MPS_FLAGS "-DCUDA_PROXY")
   endif()
 
@@ -42,7 +48,7 @@ if(GPU_API STREQUAL "CUDA")
 
   # ensure that no *cubin.h files exist from a compile in the lib/gpu folder
   file(GLOB GPU_LIB_OLD_CUBIN_HEADERS ${LAMMPS_LIB_SOURCE_DIR}/gpu/*_cubin.h)
-  if (GPU_LIB_OLD_CUBIN_HEADERS)
+  if(GPU_LIB_OLD_CUBIN_HEADERS)
     message(FATAL_ERROR "########################################################################\n"
       "Found file(s) generated by the make-based build system in lib/gpu\n"
       "Please run\n"
@@ -97,15 +103,19 @@ if(GPU_API STREQUAL "CUDA")
   if(CUDA_VERSION VERSION_GREATER_EQUAL "11.0")
     string(APPEND GPU_CUDA_GENCODE " -gencode arch=compute_80,code=[sm_80,compute_80]")
   endif()
+  # Ampere (GPU Arch 8.6) is supported by CUDA 11.1 and later
+  if(CUDA_VERSION VERSION_GREATER_EQUAL "11.1")
+    string(APPEND GPU_CUDA_GENCODE " -gencode arch=compute_86,code=[sm_86,compute_86]")
+  endif()
   if(CUDA_VERSION VERSION_GREATER_EQUAL "12.0")
     message(WARNING "Unsupported CUDA version. Use at your own risk.")
   endif()
 
   cuda_compile_fatbin(GPU_GEN_OBJS ${GPU_LIB_CU} OPTIONS ${CUDA_REQUEST_PIC}
-          -DUNIX -O3 --use_fast_math -Wno-deprecated-gpu-targets -DNV_KERNEL -DUCL_CUDADR ${GPU_CUDA_GENCODE} -D_${GPU_PREC_SETTING})
+          -DUNIX -O3 --use_fast_math -Wno-deprecated-gpu-targets -DNV_KERNEL -DUCL_CUDADR ${GPU_CUDA_GENCODE} -D_${GPU_PREC_SETTING} -DLAMMPS_${LAMMPS_SIZES})
 
   cuda_compile(GPU_OBJS ${GPU_LIB_CUDPP_CU} OPTIONS ${CUDA_REQUEST_PIC}
-          -DUNIX -O3 --use_fast_math -Wno-deprecated-gpu-targets -DUCL_CUDADR ${GPU_CUDA_GENCODE} -D_${GPU_PREC_SETTING})
+          -DUNIX -O3 --use_fast_math -Wno-deprecated-gpu-targets -DUCL_CUDADR ${GPU_CUDA_GENCODE} -D_${GPU_PREC_SETTING} -DLAMMPS_${LAMMPS_SIZES})
 
   foreach(CU_OBJ ${GPU_GEN_OBJS})
     get_filename_component(CU_NAME ${CU_OBJ} NAME_WE)
@@ -121,7 +131,7 @@ if(GPU_API STREQUAL "CUDA")
   add_library(gpu STATIC ${GPU_LIB_SOURCES} ${GPU_LIB_CUDPP_SOURCES} ${GPU_OBJS})
   target_link_libraries(gpu PRIVATE ${CUDA_LIBRARIES} ${CUDA_CUDA_LIBRARY})
   target_include_directories(gpu PRIVATE ${LAMMPS_LIB_BINARY_DIR}/gpu ${CUDA_INCLUDE_DIRS})
-  target_compile_definitions(gpu PRIVATE -D_${GPU_PREC_SETTING} -DMPI_GERYON -DUCL_NO_EXIT ${GPU_CUDA_MPS_FLAGS})
+  target_compile_definitions(gpu PRIVATE -DUSE_CUDA -D_${GPU_PREC_SETTING} -DMPI_GERYON -DUCL_NO_EXIT ${GPU_CUDA_MPS_FLAGS})
   if(CUDPP_OPT)
     target_include_directories(gpu PRIVATE ${LAMMPS_LIB_SOURCE_DIR}/gpu/cudpp_mini)
     target_compile_definitions(gpu PRIVATE -DUSE_CUDPP)
@@ -135,27 +145,20 @@ if(GPU_API STREQUAL "CUDA")
   target_include_directories(nvc_get_devices PRIVATE ${CUDA_INCLUDE_DIRS})
 
 elseif(GPU_API STREQUAL "OPENCL")
-  if(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
+  # the static OpenCL loader doesn't seem to work on macOS. use the system provided
-    # download and unpack support binaries for compilation of windows binaries.
+  # version by default instead (for as long as it will be available)
-    set(LAMMPS_THIRDPARTY_URL "https://download.lammps.org/thirdparty")
+  if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
-    file(DOWNLOAD "${LAMMPS_THIRDPARTY_URL}/opencl-win-devel.tar.gz" "${CMAKE_CURRENT_BINARY_DIR}/opencl-win-devel.tar.gz"
+    set(_opencl_static_default OFF)
-            EXPECTED_MD5 2c00364888d5671195598b44c2e0d44d)
+  else()
-    execute_process(COMMAND ${CMAKE_COMMAND} -E tar xzf opencl-win-devel.tar.gz WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    set(_opencl_static_default ON)
-    add_library(OpenCL::OpenCL UNKNOWN IMPORTED)
+  endif()
-    if(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "x86")
+  option(USE_STATIC_OPENCL_LOADER "Download and include a static OpenCL ICD loader" ${_opencl_static_default})
-      set_target_properties(OpenCL::OpenCL PROPERTIES IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/OpenCL/lib_win32/libOpenCL.dll")
+  mark_as_advanced(USE_STATIC_OPENCL_LOADER)
-    elseif(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "x86_64")
+  if(USE_STATIC_OPENCL_LOADER)
-      set_target_properties(OpenCL::OpenCL PROPERTIES IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/OpenCL/lib_win64/libOpenCL.dll")
+    include(OpenCLLoader)
-    endif()
-    set_target_properties(OpenCL::OpenCL PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_BINARY_DIR}/OpenCL/include")
   else()
     find_package(OpenCL REQUIRED)
   endif()
-  set(OCL_TUNE "generic" CACHE STRING "OpenCL Device Tuning")
-  set(OCL_TUNE_VALUES intel fermi kepler cypress generic)
-  set_property(CACHE OCL_TUNE PROPERTY STRINGS ${OCL_TUNE_VALUES})
-  validate_option(OCL_TUNE OCL_TUNE_VALUES)
-  string(TOUPPER ${OCL_TUNE} OCL_TUNE)
 
   include(OpenCLUtils)
   set(OCL_COMMON_HEADERS ${LAMMPS_LIB_SOURCE_DIR}/gpu/lal_preprocessor.h ${LAMMPS_LIB_SOURCE_DIR}/gpu/lal_aux_fun1.h)
@@ -199,7 +202,7 @@ elseif(GPU_API STREQUAL "OPENCL")
   add_library(gpu STATIC ${GPU_LIB_SOURCES})
   target_link_libraries(gpu PRIVATE OpenCL::OpenCL)
   target_include_directories(gpu PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/gpu)
-  target_compile_definitions(gpu PRIVATE -D_${GPU_PREC_SETTING} -D${OCL_TUNE}_OCL -DMPI_GERYON -DUCL_NO_EXIT)
+  target_compile_definitions(gpu PRIVATE -D_${GPU_PREC_SETTING} -DMPI_GERYON -DGERYON_NUMA_FISSION -DUCL_NO_EXIT)
   target_compile_definitions(gpu PRIVATE -DUSE_OPENCL)
 
   target_link_libraries(lammps PRIVATE gpu)
@@ -207,6 +210,7 @@ elseif(GPU_API STREQUAL "OPENCL")
   add_executable(ocl_get_devices ${LAMMPS_LIB_SOURCE_DIR}/gpu/geryon/ucl_get_devices.cpp)
   target_compile_definitions(ocl_get_devices PRIVATE -DUCL_OPENCL)
   target_link_libraries(ocl_get_devices PRIVATE OpenCL::OpenCL)
+  add_dependencies(ocl_get_devices OpenCL::OpenCL)
 elseif(GPU_API STREQUAL "HIP")
   if(NOT DEFINED HIP_PATH)
       if(NOT DEFINED ENV{HIP_PATH})
@@ -221,7 +225,7 @@ elseif(GPU_API STREQUAL "HIP")
 
   if(NOT DEFINED HIP_PLATFORM)
       if(NOT DEFINED ENV{HIP_PLATFORM})
-          set(HIP_PLATFORM "hcc" CACHE PATH "HIP Platform to be used during compilation")
+          set(HIP_PLATFORM "amd" CACHE PATH "HIP Platform to be used during compilation")
       else()
           set(HIP_PLATFORM $ENV{HIP_PLATFORM} CACHE PATH "HIP Platform used during compilation")
       endif()
@@ -229,7 +233,7 @@ elseif(GPU_API STREQUAL "HIP")
 
   set(ENV{HIP_PLATFORM} ${HIP_PLATFORM})
 
-  if(HIP_PLATFORM STREQUAL "hcc")
+  if(HIP_PLATFORM STREQUAL "hcc" OR HIP_PLATFORM STREQUAL "amd")
     set(HIP_ARCH "gfx906" CACHE STRING "HIP target architecture")
   elseif(HIP_PLATFORM STREQUAL "nvcc")
     find_package(CUDA REQUIRED)
@@ -287,23 +291,23 @@ elseif(GPU_API STREQUAL "HIP")
     set(CUBIN_FILE   "${LAMMPS_LIB_BINARY_DIR}/gpu/${CU_NAME}.cubin")
     set(CUBIN_H_FILE "${LAMMPS_LIB_BINARY_DIR}/gpu/${CU_NAME}_cubin.h")
 
-    if(HIP_PLATFORM STREQUAL "hcc")
+    if(HIP_PLATFORM STREQUAL "hcc" OR HIP_PLATFORM STREQUAL "amd")
         configure_file(${CU_FILE} ${CU_CPP_FILE} COPYONLY)
 
         if(HIP_COMPILER STREQUAL "clang")
           add_custom_command(OUTPUT ${CUBIN_FILE}
-            VERBATIM COMMAND ${HIP_HIPCC_EXECUTABLE} --genco --offload-arch=${HIP_ARCH} -O3 -ffast-math -DUSE_HIP -D_${GPU_PREC_SETTING} -I${LAMMPS_LIB_SOURCE_DIR}/gpu -o ${CUBIN_FILE} ${CU_CPP_FILE}
+            VERBATIM COMMAND ${HIP_HIPCC_EXECUTABLE} --genco --offload-arch=${HIP_ARCH} -O3 -ffast-math -DUSE_HIP -D_${GPU_PREC_SETTING} -DLAMMPS_${LAMMPS_SIZES} -I${LAMMPS_LIB_SOURCE_DIR}/gpu -o ${CUBIN_FILE} ${CU_CPP_FILE}
             DEPENDS ${CU_CPP_FILE}
             COMMENT "Generating ${CU_NAME}.cubin")
         else()
           add_custom_command(OUTPUT ${CUBIN_FILE}
-            VERBATIM COMMAND ${HIP_HIPCC_EXECUTABLE} --genco -t="${HIP_ARCH}" -f=\"-O3 -ffast-math -DUSE_HIP -D_${GPU_PREC_SETTING} -I${LAMMPS_LIB_SOURCE_DIR}/gpu\" -o ${CUBIN_FILE} ${CU_CPP_FILE}
+            VERBATIM COMMAND ${HIP_HIPCC_EXECUTABLE} --genco -t="${HIP_ARCH}" -f=\"-O3 -ffast-math -DUSE_HIP -D_${GPU_PREC_SETTING} -DLAMMPS_${LAMMPS_SIZES} -I${LAMMPS_LIB_SOURCE_DIR}/gpu\" -o ${CUBIN_FILE} ${CU_CPP_FILE}
             DEPENDS ${CU_CPP_FILE}
             COMMENT "Generating ${CU_NAME}.cubin")
         endif()
     elseif(HIP_PLATFORM STREQUAL "nvcc")
         add_custom_command(OUTPUT ${CUBIN_FILE}
-          VERBATIM COMMAND ${HIP_HIPCC_EXECUTABLE} --fatbin --use_fast_math -DUSE_HIP -D_${GPU_PREC_SETTING} ${HIP_CUDA_GENCODE} -I${LAMMPS_LIB_SOURCE_DIR}/gpu -o ${CUBIN_FILE} ${CU_FILE}
+          VERBATIM COMMAND ${HIP_HIPCC_EXECUTABLE} --fatbin --use_fast_math -DUSE_HIP -D_${GPU_PREC_SETTING} -DLAMMPS_${LAMMPS_SIZES} ${HIP_CUDA_GENCODE} -I${LAMMPS_LIB_SOURCE_DIR}/gpu -o ${CUBIN_FILE} ${CU_FILE}
           DEPENDS ${CU_FILE}
           COMMENT "Generating ${CU_NAME}.cubin")
     endif()
@@ -341,11 +345,16 @@ elseif(GPU_API STREQUAL "HIP")
 
       if(DOWNLOAD_CUB)
         message(STATUS "CUB download requested")
+        set(CUB_URL "https://github.com/NVlabs/cub/archive/1.12.0.tar.gz" CACHE STRING "URL for CUB tarball")
+        set(CUB_MD5 "1cf595beacafff104700921bac8519f3" CACHE STRING "MD5 checksum of CUB tarball")
+        mark_as_advanced(CUB_URL)
+        mark_as_advanced(CUB_MD5)
+
         include(ExternalProject)
 
         ExternalProject_Add(CUB
-          GIT_REPOSITORY https://github.com/NVlabs/cub
+          URL     ${CUB_URL}
-          TIMEOUT 5
+          URL_MD5 ${CUB_MD5}
           PREFIX "${CMAKE_CURRENT_BINARY_DIR}"
           CONFIGURE_COMMAND ""
           BUILD_COMMAND ""
@@ -357,7 +366,7 @@ elseif(GPU_API STREQUAL "HIP")
       else()
         find_package(CUB)
         if(NOT CUB_FOUND)
-          message(FATAL_ERROR "CUB library not found. Help CMake to find it by setting CUB_INCLUDE_DIR, or set DOWNLOAD_VORO=ON to download it")
+          message(FATAL_ERROR "CUB library not found. Help CMake to find it by setting CUB_INCLUDE_DIR, or set DOWNLOAD_CUB=ON to download it")
         endif()
       endif()
 
@@ -384,18 +393,21 @@ elseif(GPU_API STREQUAL "HIP")
 
     target_compile_definitions(hip_get_devices PRIVATE -D__HIP_PLATFORM_HCC__)
     target_include_directories(hip_get_devices PRIVATE ${HIP_ROOT_DIR}/../include)
+  elseif(HIP_PLATFORM STREQUAL "amd")
+    target_compile_definitions(gpu PRIVATE -D__HIP_PLATFORM_AMD__)
+    target_include_directories(gpu PRIVATE ${HIP_ROOT_DIR}/../include)
+
+    target_compile_definitions(hip_get_devices PRIVATE -D__HIP_PLATFORM_AMD__)
+    target_include_directories(hip_get_devices PRIVATE ${HIP_ROOT_DIR}/../include)
   endif()
 
   target_link_libraries(lammps PRIVATE gpu)
 endif()
 
-# GPU package
-FindStyleHeaders(${GPU_SOURCES_DIR} FIX_CLASS fix_ FIX)
-
 set_property(GLOBAL PROPERTY "GPU_SOURCES" "${GPU_SOURCES}")
-
+# detect styles which have a GPU version
-# detects styles which have GPU version
 RegisterStylesExt(${GPU_SOURCES_DIR} gpu GPU_SOURCES)
+RegisterFixStyle(${GPU_SOURCES_DIR}/fix_gpu.h)
 
 get_property(GPU_SOURCES GLOBAL PROPERTY GPU_SOURCES)
 

cmake/Modules/Packages/KIM.cmake

@@ -19,6 +19,8 @@ if(CURL_FOUND)
     target_compile_definitions(lammps PRIVATE -DLMP_NO_SSL_CHECK)
   endif()
 endif()
+set(KIM_EXTRA_UNITTESTS OFF CACHE STRING "Set extra unit tests verbose mode on/off. If on, extra tests are included.")
+mark_as_advanced(KIM_EXTRA_UNITTESTS)
 find_package(PkgConfig QUIET)
 set(DOWNLOAD_KIM_DEFAULT ON)
 if(PKG_CONFIG_FOUND)
@@ -33,9 +35,13 @@ if(DOWNLOAD_KIM)
   include(ExternalProject)
   enable_language(C)
   enable_language(Fortran)
+  set(KIM_URL "https://s3.openkim.org/kim-api/kim-api-2.2.1.txz" CACHE STRING "URL for KIM tarball")
+  set(KIM_MD5 "ae1ddda2ef7017ea07934e519d023dca" CACHE STRING "MD5 checksum of KIM tarball")
+  mark_as_advanced(KIM_URL)
+  mark_as_advanced(KIM_MD5)
   ExternalProject_Add(kim_build
-    URL https://s3.openkim.org/kim-api/kim-api-2.1.3.txz
+    URL     ${KIM_URL}
-    URL_MD5 6ee829a1bbba5f8b9874c88c4c4ebff8
+    URL_MD5 ${KIM_MD5}
     BINARY_DIR build
     CMAKE_ARGS ${CMAKE_REQUEST_PIC}
                -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
@@ -53,11 +59,28 @@ if(DOWNLOAD_KIM)
   add_library(LAMMPS::KIM UNKNOWN IMPORTED)
   set_target_properties(LAMMPS::KIM PROPERTIES
     IMPORTED_LOCATION "${INSTALL_DIR}/lib/libkim-api${CMAKE_SHARED_LIBRARY_SUFFIX}"
-    INTERFACE_INCLUDE_DIRECTORIES "${INSTALL_DIR}/include/kim-api")
+    INTERFACE_INCLUDE_DIRECTORIES "${INSTALL_DIR}/include/kim-api"
-  target_link_libraries(lammps PRIVATE LAMMPS::KIM)
+    )
   add_dependencies(LAMMPS::KIM kim_build)
+  target_link_libraries(lammps PRIVATE LAMMPS::KIM)
+  # Set rpath so lammps build directory is relocatable
+  if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+    set(_rpath_prefix "@loader_path")
+  else()
+    set(_rpath_prefix "$ORIGIN")
+  endif()
+  set_target_properties(lmp PROPERTIES
+    BUILD_RPATH "${_rpath_prefix}/kim_build-prefix/lib"
+    )
 else()
-  find_package(PkgConfig REQUIRED)
+  if(KIM-API_FOUND AND KIM-API_VERSION VERSION_GREATER_EQUAL 2.2.0)
-  pkg_check_modules(KIM-API REQUIRED IMPORTED_TARGET libkim-api>=${KIM-API_MIN_VERSION})
+    # For kim-api >= 2.2.0
-  target_link_libraries(lammps PRIVATE PkgConfig::KIM-API)
+    find_package(KIM-API 2.2.0 CONFIG REQUIRED)
+    target_link_libraries(lammps PRIVATE KIM-API::kim-api)
+  else()
+    # For kim-api 2.1.3 (consistent with previous version of this file)
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(KIM-API REQUIRED IMPORTED_TARGET libkim-api>=${KIM-API_MIN_VERSION})
+    target_link_libraries(lammps PRIVATE PkgConfig::KIM-API)
+  endif()
 endif()

cmake/Modules/Packages/KOKKOS.cmake

@@ -1,4 +1,7 @@
 ########################################################################
+# As of version 3.3.0 Kokkos requires C++14
+set(CMAKE_CXX_STANDARD 14)
+########################################################################
 # consistency checks and Kokkos options/settings required by LAMMPS
 if(Kokkos_ENABLE_CUDA)
   message(STATUS "KOKKOS: Enabling CUDA LAMBDA function support")
@@ -34,9 +37,13 @@ if(DOWNLOAD_KOKKOS)
   list(APPEND KOKKOS_LIB_BUILD_ARGS "-DCMAKE_CXX_EXTENSIONS=${CMAKE_CXX_EXTENSIONS}")
   list(APPEND KOKKOS_LIB_BUILD_ARGS "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}")
   include(ExternalProject)
+  set(KOKKOS_URL "https://github.com/kokkos/kokkos/archive/3.4.01.tar.gz" CACHE STRING "URL for KOKKOS tarball")
+  set(KOKKOS_MD5 "4c84698917c93a18985b311bb6caf84f" CACHE STRING "MD5 checksum of KOKKOS tarball")
+  mark_as_advanced(KOKKOS_URL)
+  mark_as_advanced(KOKKOS_MD5)
   ExternalProject_Add(kokkos_build
-    URL https://github.com/kokkos/kokkos/archive/3.2.00.tar.gz
+    URL     ${KOKKOS_URL}
-    URL_MD5 81569170fe232e5e64ab074f7cca5e50
+    URL_MD5 ${KOKKOS_MD5}
     CMAKE_ARGS ${KOKKOS_LIB_BUILD_ARGS}
     BUILD_BYPRODUCTS <INSTALL_DIR>/lib/libkokkoscore.a
   )
@@ -48,10 +55,12 @@ if(DOWNLOAD_KOKKOS)
     INTERFACE_INCLUDE_DIRECTORIES "${INSTALL_DIR}/include"
     INTERFACE_LINK_LIBRARIES ${CMAKE_DL_LIBS})
   target_link_libraries(lammps PRIVATE LAMMPS::KOKKOS)
+  target_link_libraries(lmp PRIVATE LAMMPS::KOKKOS)
   add_dependencies(LAMMPS::KOKKOS kokkos_build)
 elseif(EXTERNAL_KOKKOS)
-  find_package(Kokkos 3.2.00 REQUIRED CONFIG)
+  find_package(Kokkos 3.4.01 REQUIRED CONFIG)
   target_link_libraries(lammps PRIVATE Kokkos::kokkos)
+  target_link_libraries(lmp PRIVATE Kokkos::kokkos)
 else()
   set(LAMMPS_LIB_KOKKOS_SRC_DIR ${LAMMPS_LIB_SOURCE_DIR}/kokkos)
   set(LAMMPS_LIB_KOKKOS_BIN_DIR ${LAMMPS_LIB_BINARY_DIR}/kokkos)
@@ -63,6 +72,7 @@ else()
                           ${LAMMPS_LIB_KOKKOS_BIN_DIR})
   target_include_directories(lammps PRIVATE ${Kokkos_INCLUDE_DIRS})
   target_link_libraries(lammps PRIVATE kokkos)
+  target_link_libraries(lmp PRIVATE kokkos)
 endif()
 target_compile_definitions(lammps PRIVATE -DLMP_KOKKOS)
 
@@ -89,7 +99,7 @@ if(PKG_KSPACE)
                                  ${KOKKOS_PKG_SOURCES_DIR}/gridcomm_kokkos.cpp
                                  ${KOKKOS_PKG_SOURCES_DIR}/remap_kokkos.cpp)
   if(Kokkos_ENABLE_CUDA)
-    if(NOT ${FFT} STREQUAL "KISS")
+    if(NOT (FFT STREQUAL "KISS"))
       target_compile_definitions(lammps PRIVATE -DFFT_CUFFT)
       target_link_libraries(lammps PRIVATE cufft)
     endif()

cmake/Modules/Packages/LATTE.cmake

@@ -15,10 +15,14 @@ endif()
 option(DOWNLOAD_LATTE "Download the LATTE library instead of using an already installed one" ${DOWNLOAD_LATTE_DEFAULT})
 if(DOWNLOAD_LATTE)
   message(STATUS "LATTE download requested - we will build our own")
+  set(LATTE_URL "https://github.com/lanl/LATTE/archive/v1.2.2.tar.gz" CACHE STRING "URL for LATTE tarball")
+  set(LATTE_MD5 "820e73a457ced178c08c71389a385de7" CACHE STRING "MD5 checksum of LATTE tarball")
+  mark_as_advanced(LATTE_URL)
+  mark_as_advanced(LATTE_MD5)
   include(ExternalProject)
   ExternalProject_Add(latte_build
-    URL https://github.com/lanl/LATTE/archive/v1.2.2.tar.gz
+    URL     ${LATTE_URL}
-    URL_MD5 820e73a457ced178c08c71389a385de7
+    URL_MD5 ${LATTE_MD5}
     SOURCE_SUBDIR cmake
     CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR> ${CMAKE_REQUEST_PIC} -DCMAKE_INSTALL_LIBDIR=lib
     -DBLAS_LIBRARIES=${BLAS_LIBRARIES} -DLAPACK_LIBRARIES=${LAPACK_LIBRARIES}

cmake/Modules/Packages/MESSAGE.cmake

@@ -1,10 +1,9 @@
-if(LAMMPS_SIZES STREQUAL BIGBIG)
+if(LAMMPS_SIZES STREQUAL "BIGBIG")
   message(FATAL_ERROR "The MESSAGE Package is not compatible with -DLAMMPS_BIGBIG")
 endif()
 option(MESSAGE_ZMQ "Use ZeroMQ in MESSAGE package" OFF)
-file(GLOB_RECURSE cslib_SOURCES ${LAMMPS_LIB_SOURCE_DIR}/message/cslib/[^.]*.F
+file(GLOB_RECURSE cslib_SOURCES
-    ${LAMMPS_LIB_SOURCE_DIR}/message/cslib/[^.]*.c
+        ${LAMMPS_LIB_SOURCE_DIR}/message/cslib/[^.]*.cpp)
-    ${LAMMPS_LIB_SOURCE_DIR}/message/cslib/[^.]*.cpp)
 
 add_library(cslib STATIC ${cslib_SOURCES})
 target_compile_definitions(cslib PRIVATE -DLAMMPS_${LAMMPS_SIZES})

cmake/Modules/Packages/MLIAP.cmake

@@ -0,0 +1,40 @@
+# if PYTHON package is included we may also include Python support in MLIAP
+set(MLIAP_ENABLE_PYTHON_DEFAULT OFF)
+if(PKG_PYTHON)
+  find_package(Cythonize QUIET)
+  if(Cythonize_FOUND)
+    set(MLIAP_ENABLE_PYTHON_DEFAULT ON)
+  endif()
+endif()
+
+option(MLIAP_ENABLE_PYTHON "Build MLIAP package with Python support" ${MLIAP_ENABLE_PYTHON_DEFAULT})
+
+if(MLIAP_ENABLE_PYTHON)
+  find_package(Cythonize REQUIRED)
+  if(NOT PKG_PYTHON)
+    message(FATAL_ERROR "Must enable PYTHON package for including Python support in MLIAP")
+  endif()
+  if(CMAKE_VERSION VERSION_LESS 3.12)
+    if(PYTHONLIBS_VERSION_STRING VERSION_LESS 3.6)
+      message(FATAL_ERROR "Python support in MLIAP requires Python 3.6 or later")
+    endif()
+  else()
+    if(Python_VERSION VERSION_LESS 3.6)
+      message(FATAL_ERROR "Python support in MLIAP requires Python 3.6 or later")
+    endif()
+  endif()
+
+  set(MLIAP_BINARY_DIR ${CMAKE_BINARY_DIR}/cython)
+  set(MLIAP_CYTHON_SRC ${LAMMPS_SOURCE_DIR}/MLIAP/mliap_model_python_couple.pyx)
+  get_filename_component(MLIAP_CYTHON_BASE ${MLIAP_CYTHON_SRC} NAME_WE)
+  file(MAKE_DIRECTORY ${MLIAP_BINARY_DIR})
+  add_custom_command(OUTPUT  ${MLIAP_BINARY_DIR}/${MLIAP_CYTHON_BASE}.cpp ${MLIAP_BINARY_DIR}/${MLIAP_CYTHON_BASE}.h
+          COMMAND            ${CMAKE_COMMAND} -E copy_if_different ${MLIAP_CYTHON_SRC} ${MLIAP_BINARY_DIR}/${MLIAP_CYTHON_BASE}.pyx
+          COMMAND            ${Cythonize_EXECUTABLE} -3 ${MLIAP_BINARY_DIR}/${MLIAP_CYTHON_BASE}.pyx
+          WORKING_DIRECTORY  ${MLIAP_BINARY_DIR}
+          MAIN_DEPENDENCY    ${MLIAP_CYTHON_SRC}
+          COMMENT "Generating C++ sources with cythonize...")
+  target_compile_definitions(lammps PRIVATE -DMLIAP_PYTHON)
+  target_sources(lammps PRIVATE ${MLIAP_BINARY_DIR}/${MLIAP_CYTHON_BASE}.cpp)
+  target_include_directories(lammps PRIVATE ${MLIAP_BINARY_DIR})
+endif()

cmake/Modules/Packages/MSCG.cmake

@@ -7,10 +7,15 @@ else()
 endif()
 option(DOWNLOAD_MSCG "Download MSCG library instead of using an already installed one)" ${DOWNLOAD_MSCG_DEFAULT})
 if(DOWNLOAD_MSCG)
+  set(MSCG_URL "https://github.com/uchicago-voth/MSCG-release/archive/1.7.3.1.tar.gz" CACHE STRING "URL for MSCG tarball")
+  set(MSCG_MD5 "8c45e269ee13f60b303edd7823866a91" CACHE STRING "MD5 checksum of MSCG tarball")
+  mark_as_advanced(MSCG_URL)
+  mark_as_advanced(MSCG_MD5)
+
   include(ExternalProject)
   ExternalProject_Add(mscg_build
-    URL https://github.com/uchicago-voth/MSCG-release/archive/1.7.3.1.tar.gz
+    URL     ${MSCG_URL}
-    URL_MD5 8c45e269ee13f60b303edd7823866a91
+    URL_MD5 ${MSCG_MD5}
     SOURCE_SUBDIR src/CMake
     CMAKE_ARGS ${CMAKE_REQUEST_PIC} ${EXTRA_MSCG_OPTS}
                -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}

cmake/Modules/Packages/QEQ.cmake

@@ -1,18 +1,13 @@
 # Fix qeq/fire requires MANYBODY (i.e. COMB and COMB3) to be installed
 set(QEQ_SOURCES_DIR ${LAMMPS_SOURCE_DIR}/QEQ)
-file(GLOB QEQ_HEADERS ${QEQ_SOURCES_DIR}/fix*.h)
-file(GLOB QEQ_SOURCES ${QEQ_SOURCES_DIR}/fix*.cpp)
 
+get_property(hlist GLOBAL PROPERTY FIX)
 if(NOT PKG_MANYBODY)
-  list(REMOVE_ITEM QEQ_HEADERS ${QEQ_SOURCES_DIR}/fix_qeq_fire.h)
+  list(REMOVE_ITEM hlist ${QEQ_SOURCES_DIR}/fix_qeq_fire.h)
-  list(REMOVE_ITEM QEQ_SOURCES ${QEQ_SOURCES_DIR}/fix_qeq_fire.cpp)
+  get_target_property(LAMMPS_SOURCES lammps SOURCES)
+  list(REMOVE_ITEM LAMMPS_SOURCES ${QEQ_SOURCES_DIR}/fix_qeq_fire.cpp)
+  set_property(TARGET lammps PROPERTY SOURCES ${LAMMPS_SOURCES})
 endif()
-set_property(GLOBAL PROPERTY "QEQ_SOURCES" "${QEQ_SOURCES}")
+set_property(GLOBAL PROPERTY FIX "${hlist}")
 
-foreach(MY_HEADER ${QEQ_HEADERS})
-  AddStyleHeader(${MY_HEADER} FIX)
-endforeach()
-
-get_property(QEQ_SOURCES GLOBAL PROPERTY QEQ_SOURCES)
-target_sources(lammps PRIVATE ${QEQ_SOURCES})
 target_include_directories(lammps PRIVATE ${QEQ_SOURCES_DIR})

cmake/Modules/Packages/USER-HDNNP.cmake

@@ -0,0 +1,127 @@
+find_package(N2P2 QUIET)
+if(N2P2_FOUND)
+  set(DOWNLOAD_N2P2_DEFAULT OFF)
+else()
+  set(DOWNLOAD_N2P2_DEFAULT ON)
+endif()
+option(DOWNLOAD_N2P2 "Download n2p2 library instead of using an already installed one)" ${DOWNLOAD_N2P2_DEFAULT})
+if(DOWNLOAD_N2P2)
+  set(N2P2_URL "https://github.com/CompPhysVienna/n2p2/archive/v2.1.4.tar.gz" CACHE STRING "URL for n2p2 tarball")
+  set(N2P2_MD5 "9595b066636cd6b90b0fef93398297a5" CACHE STRING "MD5 checksum of N2P2 tarball")
+  mark_as_advanced(N2P2_URL)
+  mark_as_advanced(N2P2_MD5)
+
+  # adjust settings from detected compiler to compiler platform in n2p2 library
+  # set compiler specific flag to turn on C++11 syntax (required on macOS and CentOS 7)
+  if((CMAKE_CXX_COMPILER_ID STREQUAL "Clang") OR (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang"))
+    set(N2P2_COMP llvm)
+    set(N2P2_CXX_STD "-std=c++11")
+  elseif((CMAKE_CXX_COMPILER_ID STREQUAL "Intel") OR (CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM"))
+    set(N2P2_COMP intel)
+    set(N2P2_CXX_STD "-std=c++11")
+  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    set(N2P2_COMP gnu)
+    set(N2P2_CXX_STD "-std=gnu++11")
+  elseif((CMAKE_CXX_COMPILER_ID STREQUAL "PGI") OR (CMAKE_CXX_COMPILER_ID STREQUAL "NVHPC"))
+    set(N2P2_COMP gnu)
+    set(N2P2_CXX_STD "--c++11")
+  else() # default
+    set(N2P2_COMP "")
+  endif()
+
+  # pass on archive creator command. prefer compiler specific version, if set.
+  # important when using cross compiler.
+  if(CMAKE_CXX_COMPILER_AR)
+    set(N2P2_AR ${CMAKE_CXX_COMPILER_AR})
+  else()
+    set(N2P2_AR ${CMAKE_AR})
+  endif()
+
+  # adjust compilation of n2p2 library to whether MPI is requested in LAMMPS or not
+  # need special care for compiling for MPICH2 with Linux-to-Windows cross compiler.
+  if(NOT BUILD_MPI)
+    set(N2P2_PROJECT_OPTIONS "-DN2P2_NO_MPI")
+  else()
+    # get path to MPI include directory when cross-compiling to windows
+    if((CMAKE_SYSTEM_NAME STREQUAL Windows) AND CMAKE_CROSSCOMPILING)
+      get_target_property(N2P2_MPI_INCLUDE MPI::MPI_CXX INTERFACE_INCLUDE_DIRECTORIES)
+      set(N2P2_PROJECT_OPTIONS "-I ${N2P2_MPI_INCLUDE} -DMPICH_SKIP_MPICXX=1")
+      set(MPI_CXX_COMPILER ${CMAKE_CXX_COMPILER})
+    endif()
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
+      get_target_property(N2P2_MPI_INCLUDE MPI::MPI_CXX INTERFACE_INCLUDE_DIRECTORIES)
+      set(N2P2_PROJECT_OPTIONS "-I ${N2P2_MPI_INCLUDE} -DMPICH_SKIP_MPICXX=1")
+      set(MPI_CXX_COMPILER ${CMAKE_CXX_COMPILER})
+    endif()
+  endif()
+
+  # prefer GNU make, if available. N2P2 lib seems to need it.
+  find_program(N2P2_MAKE NAMES gmake make)
+
+  # override compiler (optimization) flags in n2p2 library to flags used for LAMMPS
+  # specifically -march=native can result in problems when compiling on HPC clusters or with a cross compiler
+  # this convoluted way gets correct quoting/escaping when configuring the external project
+  string(TOUPPER "${CMAKE_BUILD_TYPE}" BTYPE)
+  set(N2P2_BUILD_FLAGS "${CMAKE_SHARED_LIBRARY_CXX_FLAGS} ${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_${BTYPE}} ${N2P2_CXX_STD}")
+  set(N2P2_BUILD_OPTIONS INTERFACES=LAMMPS COMP=${N2P2_COMP} "PROJECT_OPTIONS=${N2P2_PROJECT_OPTIONS}" "PROJECT_DEBUG="
+    "PROJECT_CC=${CMAKE_CXX_COMPILER}" "PROJECT_MPICC=${MPI_CXX_COMPILER}" "PROJECT_CFLAGS=${N2P2_BUILD_FLAGS}"
+    "PROJECT_AR=${N2P2_AR}")
+  # echo final flag for debugging
+  message(STATUS "N2P2 BUILD OPTIONS: ${N2P2_BUILD_OPTIONS}")
+
+  # download compile n2p2 library. much patch MPI calls in LAMMPS interface to accommodate MPI-2 (e.g. for cross-compiling)
+  include(ExternalProject)
+  ExternalProject_Add(n2p2_build
+    URL     ${N2P2_URL}
+    URL_MD5 ${N2P2_MD5}
+    UPDATE_COMMAND ""
+    CONFIGURE_COMMAND ""
+    PATCH_COMMAND sed -i -e "s/\\(MPI_\\(P\\|Unp\\)ack(\\)/\\1(void *) /" src/libnnpif/LAMMPS/InterfaceLammps.cpp
+    BUILD_COMMAND ${N2P2_MAKE} -f makefile libnnpif ${N2P2_BUILD_OPTIONS}
+    BUILD_ALWAYS YES
+    INSTALL_COMMAND ""
+    BUILD_IN_SOURCE 1
+    LOG_BUILD ON
+    SOURCE_SUBDIR src/
+    BUILD_BYPRODUCTS <SOURCE_DIR>/lib/libnnp.a <SOURCE_DIR>/lib/libnnpif.a
+    )
+
+  # create imported target LAMMPS::N2P2 from two libraries nnp and nnpif
+  ExternalProject_get_property(n2p2_build SOURCE_DIR)
+  # n2p2 core library "libnnp"
+  add_library(LAMMPS::N2P2::LIBNNP UNKNOWN IMPORTED)
+  set_target_properties(LAMMPS::N2P2::LIBNNP PROPERTIES
+    IMPORTED_LOCATION "${SOURCE_DIR}/lib/libnnp.a"
+    INTERFACE_INCLUDE_DIRECTORIES "${SOURCE_DIR}/include")
+  # n2p2 interface library "libnnpif"
+  add_library(LAMMPS::N2P2::LIBNNPIF UNKNOWN IMPORTED)
+  set_target_properties(LAMMPS::N2P2::LIBNNPIF PROPERTIES
+    IMPORTED_LOCATION "${SOURCE_DIR}/lib/libnnpif.a"
+    INTERFACE_INCLUDE_DIRECTORIES "${SOURCE_DIR}/include")
+  # nnpif library has MPI calls if MPI is enabled, so we must link with MPI libs
+  if(BUILD_MPI)
+    set_target_properties(LAMMPS::N2P2::LIBNNPIF PROPERTIES
+      INTERFACE_LINK_LIBRARIES MPI::MPI_CXX)
+    if((CMAKE_SYSTEM_NAME STREQUAL Windows) AND CMAKE_CROSSCOMPILING)
+      add_dependencies(LAMMPS::N2P2::LIBNNPIF MPI::MPI_CXX)
+    endif()
+  endif()
+
+  # final step to define imported target
+  add_library(LAMMPS::N2P2 INTERFACE IMPORTED)
+  set_property(TARGET LAMMPS::N2P2 PROPERTY
+    INTERFACE_LINK_LIBRARIES LAMMPS::N2P2::LIBNNPIF LAMMPS::N2P2::LIBNNP)
+  target_link_libraries(lammps PRIVATE LAMMPS::N2P2)
+
+  add_dependencies(LAMMPS::N2P2 n2p2_build)
+  # work around issues with older CMake versions
+  file(MAKE_DIRECTORY "${SOURCE_DIR}/include")
+  file(MAKE_DIRECTORY "${SOURCE_DIR}/lib")
+else()
+  find_package(N2P2)
+  if(NOT N2P2_FOUND)
+    message(FATAL_ERROR "n2p2 not found, help CMake to find it by setting N2P2_DIR, or set DOWNLOAD_N2P2=ON to download it")
+  endif()
+  target_link_libraries(lammps PRIVATE N2P2::N2P2)
+  include(${N2P2_CMAKE_EXTRAS})
+endif()

cmake/Modules/Packages/USER-INTEL.cmake

@@ -30,7 +30,12 @@ if(INTEL_LRT_MODE STREQUAL "THREADS")
   endif()
 endif()
 if(INTEL_LRT_MODE STREQUAL "C++11")
-  target_compile_definitions(lammps PRIVATE -DLMP_INTEL_USELRT -DLMP_INTEL_LRT11)
+  if(Threads_FOUND)
+    target_compile_definitions(lammps PRIVATE -DLMP_INTEL_USELRT -DLMP_INTEL_LRT11)
+    target_link_libraries(lammps PRIVATE Threads::Threads)
+  else()
+    message(FATAL_ERROR "Must have working threads library for Long-range thread support")
+  endif()
 endif()
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
@@ -74,9 +79,11 @@ if(INTEL_ARCH STREQUAL "KNL")
 else()
   if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
     include(CheckCXXCompilerFlag)
-    foreach(_FLAG -O2 -fp-model fast=2 -no-prec-div -qoverride-limits -qopt-zmm-usage=high -qno-offload -fno-alias -ansi-alias -restrict)
+    foreach(_FLAG -O2 "-fp-model fast=2" -no-prec-div -qoverride-limits -qopt-zmm-usage=high -qno-offload -fno-alias -ansi-alias -restrict)
-      check_cxx_compiler_flag("${_FLAG}" COMPILER_SUPPORTS${_FLAG})
+      string(REGEX REPLACE "[ =\"]" "" _FLAGX ${_FLAG})
-      if(COMPILER_SUPPORTS${_FLAG})
+      check_cxx_compiler_flag("${_FLAG}" COMPILER_SUPPORTS${_FLAGX})
+      if(COMPILER_SUPPORTS${_FLAGX})
+          separate_arguments(_FLAG UNIX_COMMAND "${_FLAG}")
           target_compile_options(lammps PRIVATE ${_FLAG})
       endif()
     endforeach()

cmake/Modules/Packages/USER-MDI.cmake

@@ -0,0 +1,118 @@
+find_package(mdi QUIET)
+if(${mdi_FOUND})
+  set(DOWNLOAD_MDI_DEFAULT OFF)
+else()
+  set(DOWNLOAD_MDI_DEFAULT ON)
+endif()
+option(DOWNLOAD_MDI "Download and compile the MDI library instead of using an already installed one" ${DOWNLOAD_MDI_DEFAULT})
+
+if(DOWNLOAD_MDI)
+  message(STATUS "MDI download requested - we will build our own")
+  set(MDI_URL "https://github.com/MolSSI-MDI/MDI_Library/archive/v1.2.9.tar.gz" CACHE STRING "URL for MDI tarball")
+  set(MDI_MD5 "ddfa46d6ee15b4e59cfd527ec7212184" CACHE STRING "MD5 checksum for MDI tarball")
+  mark_as_advanced(MDI_URL)
+  mark_as_advanced(MDI_MD5)
+  enable_language(C)
+
+  # only ON/OFF are allowed for "mpi" flag when building MDI library
+  # so translate boolean value of BUILD_MPI
+  # always disable MPI when cross-compiling to Windows.
+  if((BUILD_MPI) AND NOT((CMAKE_SYSTEM_NAME STREQUAL "Windows") AND CMAKE_CROSSCOMPILING))
+    set(MDI_USE_MPI ON)
+  else()
+    set(MDI_USE_MPI OFF)
+  endif()
+
+  # detect if we have python development support and thus can enable python plugins
+  set(MDI_USE_PYTHON_PLUGINS OFF)
+  if(CMAKE_VERSION VERSION_LESS 3.12)
+    find_package(PythonLibs QUIET) # Deprecated since version 3.12
+    if(PYTHONLIBS_FOUND)
+      set(MDI_USE_PYTHON_PLUGINS ON)
+    endif()
+  else()
+    find_package(Python QUIET COMPONENTS Development)
+    if(Python_Development_FOUND)
+      set(MDI_USE_PYTHON_PLUGINS ON)
+    endif()
+  endif()
+
+  # download/ build MDI library
+  # always build static library with -fpic
+  # support cross-compilation and ninja-build
+  include(ExternalProject)
+  ExternalProject_Add(mdi_build
+    URL     ${MDI_URL}
+    URL_MD5 ${MDI_MD5}
+    CMAKE_ARGS ${CMAKE_REQUEST_PIC}
+    -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
+    -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+    -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+    -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
+    -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
+    -Dlanguage=C
+    -Dlibtype=STATIC
+    -Dmpi=${MDI_USE_MPI}
+    -Dpython_plugins=${MDI_USE_PYTHON_PLUGINS}
+    UPDATE_COMMAND ""
+    INSTALL_COMMAND ""
+    BUILD_BYPRODUCTS "<BINARY_DIR>/MDI_Library/libmdi.a"
+    )
+
+  # where is the compiled library?
+  ExternalProject_get_property(mdi_build BINARY_DIR)
+  set(MDI_BINARY_DIR "${BINARY_DIR}/MDI_Library")
+  # workaround for older CMake versions
+  file(MAKE_DIRECTORY ${MDI_BINARY_DIR})
+
+  # create imported target for the MDI library
+  add_library(LAMMPS::MDI UNKNOWN IMPORTED)
+  add_dependencies(LAMMPS::MDI mdi_build)
+  set_target_properties(LAMMPS::MDI PROPERTIES
+    IMPORTED_LOCATION "${MDI_BINARY_DIR}/libmdi.a"
+    INTERFACE_INCLUDE_DIRECTORIES ${MDI_BINARY_DIR}
+    )
+
+  set(MDI_DEP_LIBS "")
+  # if compiling with python plugins we need
+  # to add python libraries as dependency.
+  if(MDI_USE_PYTHON_PLUGINS)
+    if(CMAKE_VERSION VERSION_LESS 3.12)
+      list(APPEND MDI_DEP_LIBS ${PYTHON_LIBRARIES})
+    else()
+      list(APPEND MDI_DEP_LIBS Python::Python)
+    endif()
+
+  endif()
+  # need to add support for dlopen/dlsym, except when compiling for Windows.
+  if(NOT (CMAKE_SYSTEM_NAME STREQUAL "Windows"))
+    list(APPEND MDI_DEP_LIBS "${CMAKE_DL_LIBS}")
+  endif()
+  if(MDI_DEP_LIBS)
+    set_target_properties(LAMMPS::MDI PROPERTIES
+      IMPORTED_LINK_INTERFACE_LIBRARIES "${MDI_DEP_LIBS}")
+  endif()
+
+  target_link_libraries(lammps PRIVATE LAMMPS::MDI)
+  target_link_libraries(lmp PRIVATE LAMMPS::MDI)
+
+else()
+
+  find_package(mdi)
+  if(NOT mdi_FOUND)
+    message(FATAL_ERROR "MDI library not found. Help CMake to find it "
+      "by setting mdi_LIBRARY and mdi_INCLUDE_DIR, or set DOWNLOAD_MDI=ON "
+      "to download and compile it")
+  endif()
+
+  # Link the lammps library against MDI
+  target_include_directories(lammps PRIVATE ${mdi_INCLUDE_DIR})
+  target_link_libraries(lammps PRIVATE ${mdi_LIBRARY})
+
+  # Link the lammps executable against MDI
+  target_include_directories(lmp PRIVATE ${mdi_INCLUDE_DIR})
+  target_link_libraries(lmp PRIVATE ${mdi_LIBRARY})
+endif()
+
+target_compile_definitions(lammps PRIVATE -DLMP_USER_MDI)
+target_compile_definitions(lmp PRIVATE -DLMP_USER_MDI)

cmake/Modules/Packages/USER-MOLFILE.cmake

@@ -2,8 +2,4 @@ set(MOLFILE_INCLUDE_DIR "${LAMMPS_LIB_SOURCE_DIR}/molfile" CACHE STRING "Path to
 set(MOLFILE_INCLUDE_DIRS "${MOLFILE_INCLUDE_DIR}")
 add_library(molfile INTERFACE)
 target_include_directories(molfile INTERFACE ${MOLFILE_INCLUDE_DIRS})
-# no need to link with -ldl on windows
-if(NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
-  target_link_libraries(molfile INTERFACE ${CMAKE_DL_LIBS})
-endif()
 target_link_libraries(lammps PRIVATE molfile)

cmake/Modules/Packages/USER-PACE.cmake

@@ -0,0 +1,25 @@
+
+set(PACELIB_URL "https://github.com/ICAMS/lammps-user-pace/archive/refs/tags/v.2021.4.9.tar.gz" CACHE STRING "URL for PACE evaluator library sources")
+set(PACELIB_MD5 "4db54962fbd6adcf8c18d46e1798ceb5" CACHE STRING "MD5 checksum of PACE evaluator library tarball")
+mark_as_advanced(PACELIB_URL)
+mark_as_advanced(PACELIB_MD5)
+
+# download library sources to build folder
+file(DOWNLOAD ${PACELIB_URL} ${CMAKE_BINARY_DIR}/libpace.tar.gz SHOW_PROGRESS EXPECTED_HASH MD5=${PACELIB_MD5})
+
+# uncompress downloaded sources
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E remove_directory lammps-user-pace*
+  COMMAND ${CMAKE_COMMAND} -E tar xzf libpace.tar.gz
+  WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+)
+
+file(GLOB PACE_EVALUATOR_INCLUDE_DIR ${CMAKE_BINARY_DIR}/lammps-user-pace-*/USER-PACE)
+file(GLOB PACE_EVALUATOR_SOURCES ${CMAKE_BINARY_DIR}/lammps-user-pace-*/USER-PACE/*.cpp)
+list(FILTER PACE_EVALUATOR_SOURCES EXCLUDE REGEX pair_pace.cpp)
+
+add_library(pace STATIC ${PACE_EVALUATOR_SOURCES})
+set_target_properties(pace PROPERTIES CXX_EXTENSIONS ON OUTPUT_NAME lammps_pace${LAMMPS_MACHINE})
+target_include_directories(pace PUBLIC ${PACE_EVALUATOR_INCLUDE_DIR})
+target_link_libraries(lammps PRIVATE pace)
+

cmake/Modules/Packages/USER-PLUMED.cmake

@@ -53,10 +53,17 @@ if(DOWNLOAD_PLUMED)
   elseif(PLUMED_MODE STREQUAL "RUNTIME")
     set(PLUMED_BUILD_BYPRODUCTS "<INSTALL_DIR>/lib/libplumedWrapper.a")
   endif()
+
+  set(PLUMED_URL "https://github.com/plumed/plumed2/releases/download/v2.7.1/plumed-src-2.7.1.tgz" CACHE STRING "URL for PLUMED tarball")
+  set(PLUMED_MD5 "4eac6a462ec84dfe0cec96c82421b8e8" CACHE STRING "MD5 checksum of PLUMED tarball")
+
+  mark_as_advanced(PLUMED_URL)
+  mark_as_advanced(PLUMED_MD5)
+
   include(ExternalProject)
   ExternalProject_Add(plumed_build
-    URL https://github.com/plumed/plumed2/releases/download/v2.6.1/plumed-src-2.6.1.tgz
+    URL     ${PLUMED_URL}
-    URL_MD5 89a9a450fc6025299fe16af235957163
+    URL_MD5 ${PLUMED_MD5}
     BUILD_IN_SOURCE 1
     CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix=<INSTALL_DIR>
                                              ${CONFIGURE_REQUEST_PIC}
@@ -65,6 +72,7 @@ if(DOWNLOAD_PLUMED)
                                              ${PLUMED_CONFIG_OMP}
                                              CXX=${PLUMED_CONFIG_CXX}
                                              CC=${PLUMED_CONFIG_CC}
+    PATCH_COMMAND sed -i "/^#include <algorithm>/a #include <limits>" <SOURCE_DIR>/src/lepton/Operation.h
     BUILD_BYPRODUCTS ${PLUMED_BUILD_BYPRODUCTS}
   )
   ExternalProject_get_property(plumed_build INSTALL_DIR)

cmake/Modules/Packages/USER-SCAFACOS.cmake

@@ -14,15 +14,19 @@ endif()
 option(DOWNLOAD_SCAFACOS "Download ScaFaCoS library instead of using an already installed one" ${DOWNLOAD_SCAFACOS_DEFAULT})
 if(DOWNLOAD_SCAFACOS)
   message(STATUS "ScaFaCoS download requested - we will build our own")
+  set(SCAFACOS_URL "https://github.com/scafacos/scafacos/releases/download/v1.0.1/scafacos-1.0.1.tar.gz" CACHE STRING "URL for SCAFACOS tarball")
+  set(SCAFACOS_MD5 "bd46d74e3296bd8a444d731bb10c1738" CACHE STRING "MD5 checksum of SCAFACOS tarball")
+  mark_as_advanced(SCAFACOS_URL)
+  mark_as_advanced(SCAFACOS_MD5)
 
   # version 1.0.1 needs a patch to compile and linke cleanly with GCC 10 and later.
-  file(DOWNLOAD https://download.lammps.org/thirdparty/scafacos-1.0.1-fix.diff ${CMAKE_CURRENT_BINARY_DIR}/scafacos-1.0.1.fix.diff
+  file(DOWNLOAD ${LAMMPS_THIRDPARTY_URL}/scafacos-1.0.1-fix.diff ${CMAKE_CURRENT_BINARY_DIR}/scafacos-1.0.1.fix.diff
           EXPECTED_HASH MD5=4baa1333bb28fcce102d505e1992d032)
 
   include(ExternalProject)
   ExternalProject_Add(scafacos_build
-    URL https://github.com/scafacos/scafacos/releases/download/v1.0.1/scafacos-1.0.1.tar.gz
+    URL     ${SCAFACOS_URL}
-    URL_MD5 bd46d74e3296bd8a444d731bb10c1738
+    URL_MD5 ${SCAFACOS_MD5}
     PATCH_COMMAND patch -p1 < ${CMAKE_CURRENT_BINARY_DIR}/scafacos-1.0.1.fix.diff
     CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix=<INSTALL_DIR> --disable-doc
                                              --enable-fcs-solvers=fmm,p2nfft,direct,ewald,p3m

cmake/Modules/Packages/USER-SMD.cmake

@@ -7,10 +7,14 @@ endif()
 option(DOWNLOAD_EIGEN3 "Download Eigen3 instead of using an already installed one)" ${DOWNLOAD_EIGEN3_DEFAULT})
 if(DOWNLOAD_EIGEN3)
   message(STATUS "Eigen3 download requested - we will build our own")
+  set(EIGEN3_URL "https://gitlab.com/libeigen/eigen/-/archive/3.3.7/eigen-3.3.7.tar.gz" CACHE STRING "URL for Eigen3 tarball")
+  set(EIGEN3_MD5 "9e30f67e8531477de4117506fe44669b" CACHE STRING "MD5 checksum of Eigen3 tarball")
+  mark_as_advanced(EIGEN3_URL)
+  mark_as_advanced(EIGEN3_MD5)
   include(ExternalProject)
   ExternalProject_Add(Eigen3_build
-    URL https://gitlab.com/libeigen/eigen/-/archive/3.3.7/eigen-3.3.7.tar.gz
+    URL     ${EIGEN3_URL}
-    URL_MD5 9e30f67e8531477de4117506fe44669b
+    URL_MD5 ${EIGEN3_MD5}
     CONFIGURE_COMMAND "" BUILD_COMMAND "" INSTALL_COMMAND ""
   )
   ExternalProject_get_property(Eigen3_build SOURCE_DIR)

cmake/Modules/Packages/VORONOI.cmake

@@ -7,6 +7,11 @@ endif()
 option(DOWNLOAD_VORO "Download and compile the Voro++ library instead of using an already installed one" ${DOWNLOAD_VORO_DEFAULT})
 if(DOWNLOAD_VORO)
   message(STATUS "Voro++ download requested - we will build our own")
+  set(VORO_URL "${LAMMPS_THIRDPARTY_URL}/voro++-0.4.6.tar.gz" CACHE STRING "URL for Voro++ tarball")
+  set(VORO_MD5 "2338b824c3b7b25590e18e8df5d68af9" CACHE STRING "MD5 checksum for Voro++ tarball")
+  mark_as_advanced(VORO_URL)
+  mark_as_advanced(VORO_MD5)
+
   include(ExternalProject)
 
   if(BUILD_SHARED_LIBS)
@@ -22,8 +27,8 @@ if(DOWNLOAD_VORO)
   endif()
 
   ExternalProject_Add(voro_build
-    URL https://download.lammps.org/thirdparty/voro++-0.4.6.tar.gz
+    URL     ${VORO_URL}
-    URL_MD5 2338b824c3b7b25590e18e8df5d68af9
+    URL_MD5 ${VORO_MD5}
     PATCH_COMMAND patch -b -p0 < ${LAMMPS_LIB_SOURCE_DIR}/voronoi/voro-make.patch
     CONFIGURE_COMMAND ""
     BUILD_COMMAND make ${VORO_BUILD_OPTIONS}

cmake/Modules/PreventInSourceBuilds.cmake

@@ -9,7 +9,7 @@ function(prevent_in_source_builds)
   get_filename_component(bindir "${CMAKE_BINARY_DIR}" REALPATH)
 
   # disallow in-source builds
-  if("${srcdir}" STREQUAL "${bindir}" OR "${srcdir2}" STREQUAL "${bindir}" OR "${srcdir3}" STREQUAL "${bindir}")
+  if(("${srcdir}" STREQUAL "${bindir}") OR ("${srcdir2}" STREQUAL "${bindir}") OR ("${srcdir3}" STREQUAL "${bindir}"))
     message(FATAL_ERROR "\
 
 CMake must not to be run in the source directory. \

cmake/Modules/Testing.cmake

@@ -16,11 +16,14 @@ if(ENABLE_TESTING)
   set(MEMORYCHECK_COMMAND "${VALGRIND_BINARY}" CACHE FILEPATH "Memory Check Command")
   set(MEMORYCHECK_COMMAND_OPTIONS "${VALGRIND_DEFAULT_OPTIONS}" CACHE STRING "Memory Check Command Options")
 
-  # check if a faster linker is available.
+  # we need to build and link a LOT of tester executables, so it is worth checking if
-  # only verified with GNU and Clang compilers and new CMake
+  # a faster linker is available. requires GNU or Clang compiler, newer CMake.
-  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.13)
+  # also only verified with Fedora Linux > 30 and Ubuntu <= 18.04 (Ubuntu 20.04 fails)
-    if((${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU")
+  if((CMAKE_SYSTEM_NAME STREQUAL "Linux") AND (CMAKE_VERSION VERSION_GREATER_EQUAL 3.13)
-        OR (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang"))
+      AND ((CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+        OR (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")))
+    if(((CMAKE_LINUX_DISTRO STREQUAL "Ubuntu") AND (CMAKE_DISTRO_VERSION VERSION_LESS_EQUAL 18.04))
+        OR ((CMAKE_LINUX_DISTRO STREQUAL "Fedora") AND (CMAKE_DISTRO_VERSION VERSION_GREATER 30)))
       include(CheckCXXCompilerFlag)
       set(CMAKE_CUSTOM_LINKER_DEFAULT default)
       check_cxx_compiler_flag(-fuse-ld=lld HAVE_LLD_LINKER_FLAG)
@@ -53,3 +56,76 @@ if(ENABLE_TESTING)
   get_filename_component(LAMMPS_UNITTEST_BIN ${CMAKE_BINARY_DIR}/unittest ABSOLUTE)
   add_subdirectory(${LAMMPS_UNITTEST_DIR} ${LAMMPS_UNITTEST_BIN})
 endif()
+
+# Compiler specific features for testing
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  option(ENABLE_COVERAGE "Enable collecting code coverage data" OFF)
+  mark_as_advanced(ENABLE_COVERAGE)
+  if(ENABLE_COVERAGE)
+    if(CMAKE_VERSION VERSION_LESS 3.13)
+      if(CMAKE_CXX_FLAGS)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --coverage")
+      else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_${CMAKE_BUILD_TYPE}_FLAGS} --coverage")
+      endif()
+    else()
+      target_compile_options(lammps PUBLIC --coverage)
+      target_link_options(lammps PUBLIC --coverage)
+    endif()
+  endif()
+endif()
+
+#######################################
+# add custom target for IWYU analysis
+#######################################
+set(ENABLE_IWYU OFF CACHE BOOL "Add 'iwyu' build target to call the include-what-you-use tool")
+mark_as_advanced(ENABLE_IWYU)
+if(ENABLE_IWYU)
+  # enforce these settings
+  set(CMAKE_EXPORT_COMPILE_COMMANDS ON CACHE BOOL "Enable reporting compilation commands to compile_commands.json" FORCE)
+  if(NOT ((CMAKE_CXX_COMPILER_ID STREQUAL "Clang") OR (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")))
+    message(FATAL_ERROR "IWYU is only supported with Clang or GNU compilers")
+  endif()
+  # detect the "native" header folder so we can include them first
+  execute_process(COMMAND ${CMAKE_CXX_COMPILER} --print-search-dirs OUTPUT_VARIABLE IWYU_SEARCH_PATHS)
+  string(REGEX REPLACE ".*libraries: *=([^:]+):.*" "\\1/include" IWYU_EXTRA_INCLUDE_DIR ${IWYU_SEARCH_PATHS})
+  find_program(IWYU_EXE NAMES include-what-you-use iwyu)
+  find_program(IWYU_TOOL NAMES iwyu_tool iwyu-tool iwyu_tool.py)
+  if(IWYU_EXE AND IWYU_TOOL)
+    add_custom_target(
+      iwyu
+      ${IWYU_TOOL} -o clang -p ${CMAKE_CURRENT_BINARY_DIR} -- -I${IWYU_EXTRA_INCLUDE_DIR} -Xiwyu --mapping_file=${CMAKE_CURRENT_SOURCE_DIR}/iwyu/iwyu-extra-map.imp
+      COMMENT "Running IWYU")
+    add_dependencies(iwyu lammps)
+  else()
+    message(FATAL_ERROR "To use IWYU you need the include-what-you-use/iwyu executable"
+      "and the iwyu-tool/iwyu_tool script installed in your PATH")
+  endif()
+endif()
+
+#######################################
+# select code sanitizer options
+#######################################
+set(ENABLE_SANITIZER "none" CACHE STRING "Select a code sanitizer option (none (default), address, leak, thread, undefined)")
+mark_as_advanced(ENABLE_SANITIZER)
+set(ENABLE_SANITIZER_VALUES none address leak thread undefined)
+set_property(CACHE ENABLE_SANITIZER PROPERTY STRINGS ${ENABLE_SANITIZER_VALUES})
+validate_option(ENABLE_SANITIZER ENABLE_SANITIZER_VALUES)
+string(TOLOWER ${ENABLE_SANITIZER} ENABLE_SANITIZER)
+if(NOT ENABLE_SANITIZER STREQUAL "none")
+  if((${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU") OR (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang"))
+    if(CMAKE_VERSION VERSION_LESS 3.13)
+      if(CMAKE_CXX_FLAGS)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=${ENABLE_SANITIZER}")
+      else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_${CMAKE_BUILD_TYPE}_FLAGS} -fsanitize=${ENABLE_SANITIZER}")
+      endif()
+    else()
+      target_compile_options(lammps PUBLIC -fsanitize=${ENABLE_SANITIZER})
+      target_link_options(lammps PUBLIC -fsanitize=${ENABLE_SANITIZER})
+    endif()
+  else()
+    message(WARNING "ENABLE_SANITIZER option not supported by ${CMAKE_CXX_COMPILER_ID} compilers. Ignoring.")
+    set(ENABLE_SANITIZER "none")
+  endif()
+endif()

cmake/Modules/Tools.cmake

@@ -45,7 +45,7 @@ if(BUILD_LAMMPS_SHELL)
   target_include_directories(lammps-shell PRIVATE ${LAMMPS_TOOLS_DIR}/lammps-shell)
 
   # workaround for broken readline pkg-config file on FreeBSD
-  if(CMAKE_SYSTEM_NAME STREQUAL FreeBSD)
+  if(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
     target_include_directories(lammps-shell PRIVATE /usr/local/include)
   endif()
   target_link_libraries(lammps-shell PRIVATE lammps PkgConfig::READLINE)

cmake/Modules/YAML.cmake

@@ -0,0 +1,47 @@
+message(STATUS "Downloading and building YAML library")
+
+include(ExternalProject)
+set(YAML_URL "https://pyyaml.org/download/libyaml/yaml-0.2.5.tar.gz" CACHE STRING "URL for libyaml tarball")
+set(YAML_MD5 "bb15429d8fb787e7d3f1c83ae129a999" CACHE STRING "MD5 checksum of libyaml tarball")
+mark_as_advanced(YAML_URL)
+mark_as_advanced(YAML_MD5)
+
+# support cross-compilation to windows
+if(CMAKE_CROSSCOMPILING AND (CMAKE_SYSTEM_NAME STREQUAL "Windows"))
+  if(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86")
+    set(YAML_CROSS_HOST --host=i686-mingw64)
+  elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+    set(YAML_CROSS_HOST --host=x86_64-mingw64)
+  else()
+    message(FATAL_ERROR "Unsupported cross-compilation "
+      " for ${CMAKE_SYSTEM_NAME}/${CMAKE_SYSTEM_PROCESSOR}"
+      " on ${CMAKE_HOST_SYSTEM}/${CMAKE_HOST_SYSTEM_PROCESSOR}")
+  endif()
+endif()
+
+ExternalProject_Add(libyaml
+                    URL               ${YAML_URL}
+                    URL_MD5           ${YAML_MD5}
+                    SOURCE_DIR        "${CMAKE_BINARY_DIR}/yaml-src"
+                    BINARY_DIR        "${CMAKE_BINARY_DIR}/yaml-build"
+                    CONFIGURE_COMMAND <SOURCE_DIR>/configure ${CONFIGURE_REQUEST_PIC}
+                                      CXX=${CMAKE_CXX_COMPILER} CC=${CMAKE_C_COMPILER}
+                                      --prefix=<INSTALL_DIR> --disable-shared ${YAML_CROSS_HOST}
+                    BUILD_BYPRODUCTS  <INSTALL_DIR>/lib/libyaml${CMAKE_STATIC_LIBRARY_SUFFIX}
+                    TEST_COMMAND      "")
+
+ExternalProject_Get_Property(libyaml INSTALL_DIR)
+set(YAML_INCLUDE_DIR ${INSTALL_DIR}/include)
+set(YAML_LIBRARY_DIR ${INSTALL_DIR}/lib)
+
+# workaround for CMake 3.10 on ubuntu 18.04
+file(MAKE_DIRECTORY ${YAML_INCLUDE_DIR})
+file(MAKE_DIRECTORY ${YAML_LIBRARY_DIR})
+
+set(YAML_LIBRARY_PATH ${INSTALL_DIR}/lib/libyaml${CMAKE_STATIC_LIBRARY_SUFFIX})
+
+add_library(Yaml::Yaml UNKNOWN IMPORTED)
+set_target_properties(Yaml::Yaml PROPERTIES
+        IMPORTED_LOCATION ${YAML_LIBRARY_PATH}
+        INTERFACE_INCLUDE_DIRECTORIES ${YAML_INCLUDE_DIR})
+add_dependencies(Yaml::Yaml libyaml)

cmake/Modules/generate_lmpgitversion.cmake

@@ -17,7 +17,7 @@ if(GIT_FOUND AND EXISTS ${LAMMPS_DIR}/.git)
     ERROR_QUIET
     WORKING_DIRECTORY ${LAMMPS_DIR}
     OUTPUT_STRIP_TRAILING_WHITESPACE)
-  execute_process(COMMAND ${GIT_EXECUTABLE} describe --dirty=-modified
+  execute_process(COMMAND ${GIT_EXECUTABLE} describe --dirty=-modified --always
     OUTPUT_VARIABLE temp_git_describe
     ERROR_QUIET
     WORKING_DIRECTORY ${LAMMPS_DIR}

cmake/pkgconfig/liblammps.pc.in

@@ -24,7 +24,7 @@ includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
 
 Name: liblammps@LAMMPS_MACHINE@
 Description: Large-scale Atomic/Molecular Massively Parallel Simulator Library
-URL: http://lammps.sandia.gov
+URL: https://www.lammps.org
 Version: @PROJECT_VERSION@
 Requires:
 Libs: -L${libdir} -llammps@LAMMPS_MACHINE@

cmake/presets/all_off.cmake

@@ -2,16 +2,16 @@
 # an existing package selection without losing any other settings
 
 set(ALL_PACKAGES ASPHERE BODY CLASS2 COLLOID COMPRESS CORESHELL DIPOLE GPU
-        GRANULAR KIM KOKKOS KSPACE LATTE MANYBODY MC MISC MESSAGE MLIAP
+  GRANULAR KIM KOKKOS KSPACE LATTE MANYBODY MC MESSAGE MISC MLIAP MOLECULE
-        MOLECULE MPIIO MSCG OPT PERI POEMS PYTHON QEQ REPLICA RIGID SHOCK
+  MPIIO MSCG OPT PERI PLUGIN POEMS PYTHON QEQ REPLICA RIGID SHOCK SNAP SPIN
-        SNAP SPIN SRD VORONOI
+  SRD VORONOI
-        USER-ADIOS USER-ATC USER-AWPMD USER-BOCS USER-CGDNA USER-CGSDK
+  USER-ADIOS USER-ATC USER-AWPMD USER-BROWNIAN USER-BOCS USER-CGDNA USER-CGSDK
-        USER-COLVARS USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP
+  USER-COLVARS USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP USER-H5MD
-        USER-H5MD USER-INTEL USER-LB USER-MANIFOLD USER-MEAMC USER-MESODPD
+  USER-HDNNP USER-INTEL USER-LB USER-MANIFOLD USER-MDI USER-MEAMC USER-MESODPD
-        USER-MESONT USER-MGPT USER-MISC USER-MOFFF USER-MOLFILE USER-NETCDF USER-OMP
+  USER-MESONT USER-MGPT USER-MISC USER-MOFFF USER-MOLFILE USER-NETCDF USER-OMP
-        USER-PHONON USER-PLUMED USER-PTM USER-QMMM USER-QTB USER-QUIP
+  USER-PACE USER-PHONON USER-PLUMED USER-PTM USER-QMMM USER-QTB USER-QUIP USER-RANN
-        USER-REACTION USER-REAXC USER-SCAFACOS USER-SDPD USER-SMD USER-SMTBQ
+  USER-REACTION USER-REAXC USER-SCAFACOS USER-SDPD USER-SMD USER-SMTBQ USER-SPH
-        USER-SPH USER-TALLY USER-UEF USER-VTK USER-YAFF)
+  USER-TALLY USER-UEF USER-VTK USER-YAFF USER-DIELECTRIC)
 
 foreach(PKG ${ALL_PACKAGES})
   set(PKG_${PKG} OFF CACHE BOOL "" FORCE)

cmake/presets/all_on.cmake

@@ -4,16 +4,16 @@
 # with just a working C++ compiler and an MPI library.
 
 set(ALL_PACKAGES ASPHERE BODY CLASS2 COLLOID COMPRESS CORESHELL DIPOLE GPU
-        GRANULAR KIM KOKKOS KSPACE LATTE MANYBODY MC MISC MESSAGE MLIAP
+  GRANULAR KIM KOKKOS KSPACE LATTE MANYBODY MC MESSAGE MISC MLIAP MOLECULE
-        MOLECULE MPIIO MSCG OPT PERI POEMS PYTHON QEQ REPLICA RIGID SHOCK
+  MPIIO MSCG OPT PERI PLUGIN POEMS PYTHON QEQ REPLICA RIGID SHOCK SNAP SPIN
-        SNAP SPIN SRD VORONOI
+  SRD VORONOI
-        USER-ADIOS USER-ATC USER-AWPMD USER-BOCS USER-CGDNA USER-CGSDK
+  USER-ADIOS USER-ATC USER-AWPMD USER-BROWNIAN USER-BOCS USER-CGDNA USER-CGSDK
-        USER-COLVARS USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP
+  USER-COLVARS USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP USER-H5MD
-        USER-H5MD USER-INTEL USER-LB USER-MANIFOLD USER-MEAMC USER-MESODPD
+  USER-HDNNP USER-INTEL USER-LB USER-MANIFOLD USER-MDI USER-MEAMC USER-MESODPD
-        USER-MESONT USER-MGPT USER-MISC USER-MOFFF USER-MOLFILE USER-NETCDF USER-OMP
+  USER-MESONT USER-MGPT USER-MISC USER-MOFFF USER-MOLFILE USER-NETCDF USER-OMP
-        USER-PHONON USER-PLUMED USER-PTM USER-QMMM USER-QTB USER-QUIP
+  USER-PACE USER-PHONON USER-PLUMED USER-PTM USER-QMMM USER-QTB USER-QUIP USER-RANN
-        USER-REACTION USER-REAXC USER-SCAFACOS USER-SDPD USER-SMD USER-SMTBQ
+  USER-REACTION USER-REAXC USER-SCAFACOS USER-SDPD USER-SMD USER-SMTBQ USER-SPH
-        USER-SPH USER-TALLY USER-UEF USER-VTK USER-YAFF)
+  USER-TALLY USER-UEF USER-VTK USER-YAFF USER-DIELECTRIC)
 
 foreach(PKG ${ALL_PACKAGES})
   set(PKG_${PKG} ON CACHE BOOL "" FORCE)

cmake/presets/clang.cmake

@@ -1,13 +1,26 @@
 # preset that will enable clang/clang++ with support for MPI and OpenMP (on Linux boxes)
 
+# prefer flang over gfortran, if available
+find_program(CLANG_FORTRAN NAMES flang gfortran f95)
+set(ENV{OMPI_FC} ${CLANG_FORTRAN})
+
 set(CMAKE_CXX_COMPILER "clang++" CACHE STRING "" FORCE)
 set(CMAKE_C_COMPILER "clang" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_COMPILER ${CLANG_FORTRAN} CACHE STRING "" FORCE)
 set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
 set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_DEBUG "-Wall -Wextra -g -std=f95" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG -std=f95" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELEASE "-O3 -DNDEBUG -std=f95" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+
 set(MPI_CXX "clang++" CACHE STRING "" FORCE)
 set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)
-unset(HAVE_OMP_H_INCLUDE CACHE)
 
+unset(HAVE_OMP_H_INCLUDE CACHE)
 set(OpenMP_C "clang" CACHE STRING "" FORCE)
 set(OpenMP_C_FLAGS "-fopenmp" CACHE STRING "" FORCE)
 set(OpenMP_C_LIB_NAMES "omp" CACHE STRING "" FORCE)

cmake/presets/download.cmake

@@ -1,7 +1,7 @@
-# preset that turns on packages with automatic downloads of sources of potentials
+# Preset that turns on packages with automatic downloads of sources or potentials.
-# compilation of libraries like Plumed or ScaFaCoS can take a considerable amount of time.
+# Compilation of libraries like Plumed or ScaFaCoS can take a considerable amount of time.
 
-set(ALL_PACKAGES KIM LATTE MSCG VORONOI USER-PLUMED USER-SCAFACOS USER-SMD USER-MESONT)
+set(ALL_PACKAGES KIM LATTE MSCG VORONOI USER-PLUMED USER-SCAFACOS USER-SMD USER-MESONT USER-MDI USER-PACE)
 
 foreach(PKG ${ALL_PACKAGES})
   set(PKG_${PKG} ON CACHE BOOL "" FORCE)
@@ -9,9 +9,11 @@ endforeach()
 
 set(DOWNLOAD_KIM ON CACHE BOOL "" FORCE)
 set(DOWNLOAD_LATTE ON CACHE BOOL "" FORCE)
+set(DOWNLOAD_MDI ON CACHE BOOL "" FORCE)
 set(DOWNLOAD_MSCG ON CACHE BOOL "" FORCE)
 set(DOWNLOAD_VORO ON CACHE BOOL "" FORCE)
 set(DOWNLOAD_EIGEN3 ON CACHE BOOL "" FORCE)
+set(DOWNLOAD_PACE ON CACHE BOOL "" FORCE)
 set(DOWNLOAD_PLUMED ON CACHE BOOL "" FORCE)
 set(DOWNLOAD_SCAFACOS ON CACHE BOOL "" FORCE)
 

cmake/presets/gcc.cmake

@@ -2,10 +2,22 @@
 
 set(CMAKE_CXX_COMPILER "g++" CACHE STRING "" FORCE)
 set(CMAKE_C_COMPILER "gcc" CACHE STRING "" FORCE)
-set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_COMPILER "gfortran" CACHE STRING "" FORCE)
-set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_DEBUG "-Wall -g" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
 set(MPI_CXX "g++" CACHE STRING "" FORCE)
 set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)
+set(MPI_C "gcc" CACHE STRING "" FORCE)
+set(MPI_C_COMPILER "mpicc" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_DEBUG "-Wall -g" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELWITHDEBINFO "-g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(MPI_Fortran "gfortran" CACHE STRING "" FORCE)
+set(MPI_Fortran_COMPILER "mpifort" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_DEBUG "-Wall -g" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELWITHDEBINFO "-g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
 unset(HAVE_OMP_H_INCLUDE CACHE)
 
 set(OpenMP_C "gcc" CACHE STRING "" FORCE)

cmake/presets/intel.cmake

@@ -3,10 +3,20 @@
 set(CMAKE_CXX_COMPILER "icpc" CACHE STRING "" FORCE)
 set(CMAKE_C_COMPILER "icc" CACHE STRING "" FORCE)
 set(CMAKE_Fortran_COMPILER "ifort" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+
 set(MPI_CXX "icpc" CACHE STRING "" FORCE)
 set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)
-unset(HAVE_OMP_H_INCLUDE CACHE)
 
+unset(HAVE_OMP_H_INCLUDE CACHE)
 set(OpenMP_C "icc" CACHE STRING "" FORCE)
 set(OpenMP_C_FLAGS "-qopenmp" CACHE STRING "" FORCE)
 set(OpenMP_C_LIB_NAMES "omp" CACHE STRING "" FORCE)

cmake/presets/mingw-cross.cmake

@@ -1,13 +1,13 @@
 set(WIN_PACKAGES ASPHERE BODY CLASS2 COLLOID COMPRESS CORESHELL DIPOLE GPU
                  GRANULAR KSPACE LATTE MANYBODY MC MISC MLIAP MOLECULE OPT
                  PERI POEMS QEQ REPLICA RIGID SHOCK SNAP SPIN SRD VORONOI
-                 USER-ATC USER-AWPMD USER-BOCS USER-CGDNA USER-CGSDK
+                 USER-ATC USER-AWPMD USER-BOCS USER-BROWNIAN USER-CGDNA USER-CGSDK
-                 USER-COLVARS USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF
+                 USER-COLVARS USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP
-                 USER-FEP USER-INTEL USER-MANIFOLD USER-MEAMC USER-MESODPD
+                 USER-HDNNP USER-INTEL USER-MANIFOLD USER-MDI USER-MEAMC USER-MESODPD
                  USER-MESONT USER-MISC USER-MGPT USER-MOFFF USER-MOLFILE USER-OMP
                  USER-PHONON USER-PTM USER-QTB USER-REACTION USER-REAXC
                  USER-SDPD USER-SMD USER-SMTBQ USER-SPH USER-TALLY USER-UEF
-                 USER-YAFF)
+                 USER-YAFF USER-DIELECTRIC)
 
 foreach(PKG ${WIN_PACKAGES})
   set(PKG_${PKG} ON CACHE BOOL "" FORCE)

cmake/presets/most.cmake

@@ -4,11 +4,11 @@
 
 set(ALL_PACKAGES ASPHERE BODY CLASS2 COLLOID COMPRESS CORESHELL DIPOLE
         GRANULAR KSPACE MANYBODY MC MISC MLIAP MOLECULE OPT PERI
-        POEMS PYTHON QEQ REPLICA RIGID SHOCK SNAP SPIN SRD VORONOI
+        PLUGIN POEMS PYTHON QEQ REPLICA RIGID SHOCK SNAP SPIN SRD VORONOI
-        USER-BOCS USER-CGDNA USER-CGSDK USER-COLVARS USER-DIFFRACTION
+        USER-BROWNIAN USER-BOCS USER-CGDNA USER-CGSDK USER-COLVARS
-        USER-DPD USER-DRUDE USER-EFF USER-FEP USER-MEAMC USER-MESODPD
+        USER-DIFFRACTION USER-DPD USER-DRUDE USER-EFF USER-FEP USER-MEAMC
-        USER-MISC USER-MOFFF USER-OMP USER-PHONON USER-REACTION
+        USER-MESODPD USER-MISC USER-MOFFF USER-OMP USER-PHONON USER-REACTION
-        USER-REAXC USER-SDPD USER-SPH USER-SMD USER-UEF USER-YAFF)
+        USER-REAXC USER-SDPD USER-SPH USER-SMD USER-UEF USER-YAFF USER-DIELECTRIC)
 
 foreach(PKG ${ALL_PACKAGES})
   set(PKG_${PKG} ON CACHE BOOL "" FORCE)

cmake/presets/nolib.cmake

@@ -1,10 +1,11 @@
 # preset that turns off all packages that require some form of external
 # library or special compiler (fortran or cuda) or equivalent.
 
-set(PACKAGES_WITH_LIB COMPRESS GPU KIM KOKKOS LATTE MPIIO MSCG PYTHON
+set(PACKAGES_WITH_LIB COMPRESS GPU KIM KOKKOS LATTE MESSAGE MPIIO MSCG
-        VORONOI USER-ADIOS USER-ATC USER-AWPMD USER-H5MD USER-LB
+  PYTHON VORONOI
-        USER-MOLFILE USER-MESONT USER-NETCDF USER-PLUMED USER-QMMM USER-QUIP
+  USER-ADIOS USER-ATC USER-AWPMD USER-H5MD USER-HDNNP USER-LB USER-MOLFILE
-        USER-SCAFACOS USER-SMD USER-VTK)
+  USER-MESONT USER-MDI USER-NETCDF USER-PACE USER-PLUMED USER-QMMM USER-QUIP
+  USER-SCAFACOS USER-SMD USER-VTK)
 
 foreach(PKG ${PACKAGES_WITH_LIB})
   set(PKG_${PKG} OFF CACHE BOOL "" FORCE)

cmake/presets/oneapi.cmake

@@ -0,0 +1,28 @@
+# preset that will enable the LLVM based Intel compilers with support for MPI and OpenMP and Fortran (on Linux boxes)
+
+set(CMAKE_CXX_COMPILER "icpx" CACHE STRING "" FORCE)
+set(CMAKE_C_COMPILER "icx" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_COMPILER "ifx" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
+
+set(MPI_CXX "icpx" CACHE STRING "" FORCE)
+set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)
+
+unset(HAVE_OMP_H_INCLUDE CACHE)
+set(OpenMP_C "icx" CACHE STRING "" FORCE)
+set(OpenMP_C_FLAGS "-qopenmp" CACHE STRING "" FORCE)
+set(OpenMP_C_LIB_NAMES "omp" CACHE STRING "" FORCE)
+set(OpenMP_CXX "icpx" CACHE STRING "" FORCE)
+set(OpenMP_CXX_FLAGS "-qopenmp" CACHE STRING "" FORCE)
+set(OpenMP_CXX_LIB_NAMES "omp" CACHE STRING "" FORCE)
+set(OpenMP_Fortran_FLAGS "-qopenmp" CACHE STRING "" FORCE)
+set(OpenMP_omp_LIBRARY "libiomp5.so" CACHE PATH "" FORCE)
+

cmake/presets/pedantic.cmake

@@ -0,0 +1,26 @@
+# preset that will restore gcc/g++ with support for MPI and OpenMP (on Linux boxes)
+
+set(CMAKE_CXX_COMPILER "g++" CACHE STRING "" FORCE)
+set(CMAKE_C_COMPILER "gcc" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_COMPILER "gfortran" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Wextra -Werror=vla -Wno-maybe-uninitialized -g" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Wall -Wextra -Werror=vla -Wno-maybe-uninitialized -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_CXX_FLAGS_RELEASE "-Wall -O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(MPI_CXX "g++" CACHE STRING "" FORCE)
+set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)
+set(MPI_C "gcc" CACHE STRING "" FORCE)
+set(MPI_C_COMPILER "mpicc" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_DEBUG "-Wall -Wextra -Wno-maybe-uninitialized -g" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELWITHDEBINFO "-Wall -Wextra -Wno-maybe-uninitialized -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
+set(CMAKE_C_FLAGS_RELEASE "-Wall -O3 -DNDEBUG" CACHE STRING "" FORCE)
+set(MPI_Fortran "gfortran" CACHE STRING "" FORCE)
+set(MPI_Fortran_COMPILER "mpifort" CACHE STRING "" FORCE)
+unset(HAVE_OMP_H_INCLUDE CACHE)
+
+set(OpenMP_C "gcc" CACHE STRING "" FORCE)
+set(OpenMP_C_FLAGS "-fopenmp" CACHE STRING "" FORCE)
+set(OpenMP_C_LIB_NAMES "gomp" CACHE STRING "" FORCE)
+set(OpenMP_CXX "g++" CACHE STRING "" FORCE)
+set(OpenMP_CXX_FLAGS "-fopenmp" CACHE STRING "" FORCE)
+set(OpenMP_CXX_LIB_NAMES "gomp" CACHE STRING "" FORCE)
+set(OpenMP_omp_LIBRARY "libgomp.so" CACHE PATH "" FORCE)

cmake/presets/pgi.cmake

@@ -0,0 +1,16 @@
+# preset that will enable clang/clang++ with support for MPI and OpenMP (on Linux boxes)
+
+set(CMAKE_CXX_COMPILER "pgc++" CACHE STRING "" FORCE)
+set(CMAKE_C_COMPILER "pgcc" CACHE STRING "" FORCE)
+set(CMAKE_Fortran_COMPILER "pgfortran" CACHE STRING "" FORCE)
+set(MPI_CXX "pgc++" CACHE STRING "" FORCE)
+set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)
+unset(HAVE_OMP_H_INCLUDE CACHE)
+
+set(OpenMP_C "pgcc" CACHE STRING "" FORCE)
+set(OpenMP_C_FLAGS "-mp" CACHE STRING "" FORCE)
+set(OpenMP_C_LIB_NAMES "omp" CACHE STRING "" FORCE)
+set(OpenMP_CXX "pgc++" CACHE STRING "" FORCE)
+set(OpenMP_CXX_FLAGS "-mp" CACHE STRING "" FORCE)
+set(OpenMP_CXX_LIB_NAMES "omp" CACHE STRING "" FORCE)
+set(OpenMP_omp_LIBRARY "libomp.so" CACHE PATH "" FORCE)

doc/Makefile

@@ -10,7 +10,6 @@ endif
 BUILDDIR       = ${CURDIR}
 RSTDIR         = $(BUILDDIR)/src
 VENV           = $(BUILDDIR)/docenv
-TXT2RST        = $(VENV)/bin/txt2rst
 ANCHORCHECK    = $(VENV)/bin/rst_anchor_check
 SPHINXCONFIG   = $(BUILDDIR)/utils/sphinx-config
 MATHJAX        = $(SPHINXCONFIG)/_static/mathjax
@@ -47,6 +46,8 @@ HAS_PDFLATEX = YES
 endif
 endif
 
+# override settings for PIP commands
+# PIP_OPTIONS = --cert /etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt --proxy http://proxy.mydomain.org
 
 #SPHINXEXTRA = -j $(shell $(PYTHON) -c 'import multiprocessing;print(multiprocessing.cpu_count())') $(shell test -f $(BUILDDIR)/doxygen/xml/run.stamp && printf -- "-E")
 
@@ -57,7 +58,7 @@ SPHINXEXTRA = -E -j $(shell $(PYTHON) -c 'import multiprocessing;print(multiproc
 # we only want to use explicitly listed files.
 DOXYFILES      = $(shell sed -n -e 's/\#.*$$//' -e '/^ *INPUT \+=/,/^[A-Z_]\+ \+=/p' doxygen/Doxyfile.in | sed -e 's/@LAMMPS_SOURCE_DIR@/..\/src/g' -e 's/\\//g' -e 's/ \+/ /' -e 's/[A-Z_]\+ \+= *\(YES\|NO\|\)//') 
 
-.PHONY: help clean-all clean clean-spelling epub mobi rst html pdf spelling anchor_check style_check xmlgen
+.PHONY: help clean-all clean clean-spelling epub mobi rst html pdf spelling anchor_check style_check char_check xmlgen
 
 # ------------------------------------------
 
@@ -66,7 +67,6 @@ help:
 	@echo "Please use \`make <target>' where <target> is one of"
 	@echo "  html          create HTML pages in html dir"
 	@echo "  pdf           create Manual.pdf in this dir"
-	@echo "  fetch         fetch HTML and PDF files from LAMMPS web site"
 	@echo "  epub          create ePUB format manual for e-book readers"
 	@echo "  mobi          convert ePUB to MOBI format manual for e-book readers (e.g. Kindle)"
 	@echo "                      (requires ebook-convert tool from calibre)"
@@ -94,7 +94,7 @@ $(SPHINXCONFIG)/conf.py: $(SPHINXCONFIG)/conf.py.in
 	    -e 's,@LAMMPS_PYTHON_DIR@,$(BUILDDIR)/../python,g' \
 	    -e 's,@LAMMPS_DOC_DIR@,$(BUILDDIR),g' $< > $@
 
-html: xmlgen $(SPHINXCONFIG)/conf.py $(ANCHORCHECK) $(MATHJAX)
+html: xmlgen $(VENV) $(SPHINXCONFIG)/conf.py $(ANCHORCHECK) $(MATHJAX)
 	@if [ "$(HAS_BASH)" == "NO" ] ; then echo "bash was not found at $(OSHELL)! Please use: $(MAKE) SHELL=/path/to/bash" 1>&2; exit 1; fi
 	@$(MAKE) $(MFLAGS) -C graphviz all
 	@(\
@@ -118,7 +118,7 @@ html: xmlgen $(SPHINXCONFIG)/conf.py $(ANCHORCHECK) $(MATHJAX)
 	@rm -rf html/PDF/.[sg]*
 	@echo "Build finished. The HTML pages are in doc/html."
 
-spelling: xmlgen $(VENV) $(SPHINXCONFIG)/false_positives.txt
+spelling: xmlgen $(SPHINXCONFIG)/conf.py $(VENV) $(SPHINXCONFIG)/false_positives.txt
 	@if [ "$(HAS_BASH)" == "NO" ] ; then echo "bash was not found at $(OSHELL)! Please use: $(MAKE) SHELL=/path/to/bash" 1>&2; exit 1; fi
 	@(\
 		. $(VENV)/bin/activate ; env PYTHONWARNINGS= \
@@ -183,13 +183,6 @@ pdf: xmlgen $(VENV) $(SPHINXCONFIG)/conf.py $(ANCHORCHECK)
 	@rm -rf latex/PDF/.[sg]*
 	@echo "Build finished. Manual.pdf is in this directory."
 
-fetch:
-	@rm -rf html_www Manual_www.pdf
-	@curl -s -o Manual_www.pdf http://lammps.sandia.gov/doc/Manual.pdf
-	@curl -s -o lammps-doc.tar.gz http://lammps.sandia.gov/tars/lammps-doc.tar.gz
-	@tar xzf lammps-doc.tar.gz
-	@rm -f lammps-doc.tar.gz
-
 anchor_check : $(ANCHORCHECK)
 	@(\
 		. $(VENV)/bin/activate ;\
@@ -211,6 +204,9 @@ package_check : $(VENV)
 		deactivate ;\
 	)
 
+char_check :
+	@( env LC_ALL=C grep -n '[^ -~]' $(RSTDIR)/*.rst && exit 1 || : )
+
 xmlgen : doxygen/xml/index.xml
 
 doxygen/Doxyfile: doxygen/Doxyfile.in
@@ -228,15 +224,15 @@ $(VENV):
 	@( \
 		$(VIRTUALENV) -p $(PYTHON) $(VENV); \
 		. $(VENV)/bin/activate; \
-		pip install --upgrade pip; \
+		pip $(PIP_OPTIONS) install --upgrade pip; \
-		pip install --use-feature=2020-resolver -r $(BUILDDIR)/utils/requirements.txt; \
+		pip $(PIP_OPTIONS) install -r $(BUILDDIR)/utils/requirements.txt; \
 		deactivate;\
 	)
 
 $(MATHJAX):
-	@git clone --depth 1 https://github.com/mathjax/MathJax.git $@
+	@git clone -b 3.2.0 -c advice.detachedHead=0 --depth 1 git://github.com/mathjax/MathJax.git $@
 
-$(TXT2RST) $(ANCHORCHECK): $(VENV)
+$(ANCHORCHECK): $(VENV)
 	@( \
 		. $(VENV)/bin/activate; \
 		(cd utils/converters;\

doc/README

@@ -25,16 +25,11 @@ github-development-workflow.md   notes on the LAMMPS development workflow
 include-file-conventions.md      notes on LAMMPS' include file conventions
 documentation_conventions.md     notes on writing documentation for LAMMPS
 
-If you downloaded a LAMMPS tarball from lammps.sandia.gov, then the html
+If you downloaded a LAMMPS tarball from www.lammps.org, then the html
 folder and the PDF manual should be included. If you downloaded LAMMPS
-from GitHub then you either need to download them or build them.
+from GitHub then you either need to build them.
 
-(a) You can "fetch" the current HTML and PDF files from the LAMMPS web
+You can build the HTML and PDF files yourself, by typing "make html"
-site.  Just type "make fetch".  This should create a html_www directory
-and Manual_www.pdf file.  These will always represent the latest published
-patch/development version of LAMMPS.
-
-(b) You can build the HTML and PDF files yourself, by typing "make html"
 or by "make pdf", respectively.  This requires various tools and files.
 Some of them have to be installed (more on that below).  For the rest the
 build process will attempt to download and install into a python virtual
@@ -78,4 +73,4 @@ the tool 'ebook-convert' from the 'calibre' e-book management software
 ----------------
 
 More details this can be found in the manual itself. The online
-version is at: https://lammps.sandia.gov/doc/Manual_build.html
+version is at: https://docs.lammps.org/Build_manual.html

doc/doxygen/Doxyfile.in

@@ -424,6 +424,8 @@ INPUT                  = @LAMMPS_SOURCE_DIR@/utils.cpp                 \
                          @LAMMPS_SOURCE_DIR@/input.h                   \
                          @LAMMPS_SOURCE_DIR@/tokenizer.cpp             \
                          @LAMMPS_SOURCE_DIR@/tokenizer.h               \
+                         @LAMMPS_SOURCE_DIR@/arg_info.cpp              \
+                         @LAMMPS_SOURCE_DIR@/arg_info.h                \
                          @LAMMPS_SOURCE_DIR@/text_file_reader.cpp      \
                          @LAMMPS_SOURCE_DIR@/text_file_reader.h        \
                          @LAMMPS_SOURCE_DIR@/potential_file_reader.cpp \

doc/github-development-workflow.md

@@ -95,7 +95,7 @@ on the pull request discussion page on GitHub, so that other developers
 can later review the entire discussion after the fact and understand the
 rationale behind choices made.  Exceptions to this policy are technical
 discussions, that are centered on tools or policies themselves
-(git, github, c++) rather than on the content of the pull request.
+(git, GitHub, c++) rather than on the content of the pull request.
 
 ### Checklist for Pull Requests
 

doc/graphviz/lammps-classes.dot

@@ -18,8 +18,8 @@ digraph lammps {
     Up [shape=box label="Update" color=blue]
     Un [shape=box label="Universe" color=blue]
     Ti [shape=box label="Timer" color=blue]
-    Lt [label="Lattice"]
     Rg [label="Region" color=red]
+    Lt [label="Lattice"]
     Rb [shape=box label="RegionBlock"]
     Rs [shape=box label="RegionSphere"]
     Av [label="AtomVec" color=red]
@@ -34,6 +34,7 @@ digraph lammps {
     Du [label="Dump" color=red]
     Fi [label="Fix" color=red]
     Cp [label="Compute" color=red]
+    Cm [label="Command" color=red]
     Th [label="Thermo"]
     Va [label="Variable"]
     Ew [shape=box label="Ewald"]
@@ -71,16 +72,19 @@ digraph lammps {
     Dg [shape=box label="DumpCFG"]
     Ve [shape=box label="Verlet"]
     Rr [shape=box label="Respa"]
+    Ru [shape=box label="Run"]
+    Se [shape=box label="Set"]
     Pt [shape=box label="PPPMTIP4P"]
     Vs [shape=box label="VerletSplit"]
     Ro [shape=box label="RespaOMP"]
     Mc [shape=box label="MinCG"]
     Mf [shape=box label="MinFire"]
     La -> {At Ci Co Do Er Fo Gr In Me Mo Ne Ou Ti Up Un} [penwidth=2]
-    Do -> {Lt Rg} [penwidth=2]
+    Do -> {Rg Lt} [penwidth=2]
     Rg -> {Rb Rs} [style=dashed penwidth=2]
     Co -> {Cb Ct} [style=dashed penwidth=2]
-    In -> Va [penwidth=2]
+    In -> {Va Cm} [penwidth=2]
+    Cm -> {Ru Se} [style=dashed penwidth=2]
     Mo -> {Fi Cp} [penwidth=2]
     Fo -> {Pa Bo An Di Im Ks} [penwidth=2]
     Ks -> {Ew Pp} [style=dashed penwidth=2]

doc/lammps.1

@@ -1,4 +1,4 @@
-.TH LAMMPS "29 October 2020" "2020-10-29"
+.TH LAMMPS "27 May 2021" "2021-05-27"
 .SH NAME
 .B LAMMPS
 \- Molecular Dynamics Simulator.
@@ -34,7 +34,7 @@ semiconductors) and coarse-grained or mesoscopic systems. It can be used to
 model atoms or, more generically, as a parallel particle simulator at the
 atomic, meso, or continuum scale.
 
-See https://lammps.sandia.gov/ for more information and documentation.
+See https://www.lammps.org/ for more information and documentation.
 
 .SH EXECUTABLE NAME
 The

doc/src/Bibliography.rst

@@ -1129,6 +1129,9 @@ Bibliography
 **(Sutmann)**
    Sutmann, Arnold, Fahrenberger, et. al., Physical review / E 88(6), 063308 (2013)
 
+**(Sutmann)** G. Sutmann. ScaFaCoS - a Scalable library of Fast Coulomb Solvers for particle Systems.
+  In Bajaj, Zavattieri, Koslowski, Siegmund, Proceedings of the Society of Engineering Science 51st Annual Technical Meeting. 2014.
+
 **(Swinburne)**
    Swinburne and Marinica, Physical Review Letters, 120, 1 (2018)
 
@@ -1285,9 +1288,6 @@ Bibliography
 **(Wennberg)**
    Wennberg, Murtola, Hess, Lindahl, J Chem Theory Comput, 9, 3527 (2013).
 
-**(Who)**
-   Who, Author2, Author3, J of Long Range Solvers, 35, 164-177 (2012).
-
 **(Wicaksono1)**
    Wicaksono, Sinclair, Militzer, Computational Materials Science, 117, 397-405 (2016).
 

doc/src/Build_basics.rst

@@ -1,7 +1,7 @@
 Basic build options
 ===================
 
-The following topics are covered on this page, for building both with
+The following topics are covered on this page, for building with both
 CMake and make:
 
 * :ref:`Serial vs parallel build <serial>`
@@ -95,7 +95,7 @@ standard. A more detailed discussion of that is below.
 
       .. note::
 
-         The file ``src/STUBS/mpi.c`` provides a CPU timer function
+         The file ``src/STUBS/mpi.cpp`` provides a CPU timer function
          called ``MPI_Wtime()`` that calls ``gettimeofday()``.  If your
          operating system does not support ``gettimeofday()``, you will
          need to insert code to call another timer.  Note that the
@@ -234,14 +234,21 @@ LAMMPS.
          cmake ../cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_Fortran_COMPILER=gfortran
          # Building with Intel Compilers:
          cmake ../cmake -DCMAKE_C_COMPILER=icc -DCMAKE_CXX_COMPILER=icpc -DCMAKE_Fortran_COMPILER=ifort
+         # Building with Intel oneAPI Compilers:
+         cmake ../cmake -DCMAKE_C_COMPILER=icx -DCMAKE_CXX_COMPILER=icpx -DCMAKE_Fortran_COMPILER=ifx
          # Building with LLVM/Clang Compilers:
          cmake ../cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_Fortran_COMPILER=flang
+         # Building with PGI/Nvidia Compilers:
+         cmake ../cmake -DCMAKE_C_COMPILER=pgcc -DCMAKE_CXX_COMPILER=pgc++ -DCMAKE_Fortran_COMPILER=pgfortran
 
       For compiling with the Clang/LLVM compilers a CMake preset is
       provided that can be loaded with
       `-C ../cmake/presets/clang.cmake`.  Similarly,
       `-C ../cmake/presets/intel.cmake` should switch the compiler
-      toolchain to the Intel compilers.
+      toolchain to the legacy Intel compilers, `-C ../cmake/presets/oneapi.cmake`
+      will switch to the LLVM based oneAPI Intel compilers,
+      and `-C ../cmake/presets/pgi.cmake`
+      will switch the compiler to the PGI compilers.
 
       In addition you can set ``CMAKE_TUNE_FLAGS`` to specifically add
       compiler flags to tune for optimal performance on given hosts. By
@@ -523,6 +530,20 @@ you want to copy files to is protected.
          make                        # perform make after CMake command
          make install                # perform the installation into prefix
 
+      During the installation process CMake will by default remove any runtime
+      path settings for loading shared libraries.  Because of this you may
+      have to set or modify the ``LD_LIBRARY_PATH`` (or ``DYLD_LIBRARY_PATH``)
+      environment variable, if you are installing LAMMPS into a non-system
+      location and/or are linking to libraries in a non-system location that
+      depend on such runtime path settings.
+      As an alternative you may set the CMake variable ``LAMMPS_INSTALL_RPATH``
+      to ``on`` and then the runtime paths for any linked shared libraries
+      and the library installation folder for the LAMMPS library will be
+      embedded and thus the requirement to set environment variables is avoided.
+      The ``off`` setting is usually preferred for packaged binaries or when
+      setting up environment modules, the ``on`` setting is more convenient
+      for installing software into a non-system or personal folder.
+
    .. tab:: Traditional make
 
       There is no "install" option in the ``src/Makefile`` for LAMMPS.

doc/src/Build_development.rst

@@ -28,6 +28,28 @@ variable VERBOSE set to 1:
 
 ----------
 
+.. _clang-tidy:
+
+Enable static code analysis with clang-tidy
+-------------------------------------------
+
+The `clang-tidy tool <https://clang.llvm.org/extra/clang-tidy/>`_ is a
+static code analysis tool to diagnose (and potentially fix) typical
+programming errors or coding style violations.  It has a modular framework
+of tests that can be adjusted to help identifying problems before they
+become bugs and also assist in modernizing large code bases (like LAMMPS).
+It can be enabled for all C++ code with the following CMake flag
+
+.. code-block:: bash
+
+   -D ENABLE_CLANG_TIDY=value    # value = no (default) or yes
+
+With this flag enabled all source files will be processed twice, first to
+be compiled and then to be analyzed. Please note that the analysis can be
+significantly more time consuming than the compilation itself.
+
+----------
+
 .. _iwyu_processing:
 
 Report missing and unneeded '#include' statements
@@ -108,11 +130,18 @@ results over a given number of steps and operations within a given
 error margin).  The status of this automated testing can be viewed on
 `https://ci.lammps.org <https://ci.lammps.org>`_.
 
+The scripts and inputs for integration, run, and regression testing
+are maintained in a
+`separate repository <https://github.com/lammps/lammps-testing>`_
+of the LAMMPS project on GitHub.
+
 The unit testing facility is integrated into the CMake build process
 of the LAMMPS source code distribution itself.  It can be enabled by
 setting ``-D ENABLE_TESTING=on`` during the CMake configuration step.
-It requires the `PyYAML <http://pyyaml.org/>`_ library and development
+It requires the `YAML <http://pyyaml.org/>`_ library and development
-headers to compile and will download and compile a recent version of the
+headers (if those are not found locally a recent version will be
+downloaded and compiled along with LAMMPS and the test program) to
+compile and will download and compile a specific recent version of the
 `Googletest <https://github.com/google/googletest/>`_ C++ test framework
 for implementing the tests.
 
@@ -162,22 +191,21 @@ The ``ctest`` command has many options, the most important ones are:
 In its full implementation, the unit test framework will consist of multiple
 kinds of tests implemented in different programming languages (C++, C, Python,
 Fortran) and testing different aspects of the LAMMPS software and its features.
-At the moment only tests for "force styles" are implemented. More on those
+The tests will adapt to the compilation settings of LAMMPS, so that tests
-in the next section.
+will be skipped if prerequisite features are not available in LAMMPS.
 
 .. note::
 
-   The unit test framework is new and still under development.
+   The unit test framework was added in spring 2020 and is under active
-   The coverage is only minimal and will be expanded over time.
+   development.  The coverage is not complete and will be expanded over
-   Tests styles of the same kind of style (e.g. pair styles or
+   time.
-   bond styles) are performed with the same executable using
+
-   different input files in YAML format.  So to add a test for
+Tests for styles of the same kind of style (e.g. pair styles or bond
-   another pair style can be done by copying the YAML file and
+styles) are performed with the same test executable using different
-   editing the style settings and then running the individual test
+input files in YAML format.  So to add a test for another style of the
-   program with a flag to update the computed reference data.
+same kind it may be sufficient to add a suitable YAML file.
-   Detailed documentation about how to add new test program and
+:doc:`Detailed instructions for adding tests <Developer_unittest>` are
-   the contents of the YAML files for existing test programs
+provided in the Programmer Guide part of the manual.
-   will be provided in time as well.
 
 Unit tests for force styles
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -441,12 +469,24 @@ The following options are available.
 
 .. code-block:: bash
 
-   make check-whitespace    # generate coverage report in HTML format
+   make check-whitespace    # search for files with whitespace issues
-   make fix-whitespace      # generate coverage report in XML format
+   make fix-whitespace      # correct whitespace issues in files
-   make check-permissions   # delete folder with HTML format coverage report
+   make check-homepage      # search for files with old LAMMPS homepage URLs
-   make fix-permissions     # delete all collected coverage data and HTML output
+   make fix-homepage        # correct LAMMPS homepage URLs in files
+   make check-permissions   # search for files with permissions issues
+   make fix-permissions     # correct permissions issues in files
 
-For the code in the ``unittest`` tree we are using the `clang-format`
+For the code in the ``unittest`` and ``src`` trees we are transitioning
-tool (Clang version 8.0 or later is required). If available, the source
+to use the `clang-format` tool to assist with having a consistent source
-code files in the ``unittest`` tree can be updated to conform to the
+code style.  The `clang-format` command bundled with Clang version 8.0
-formatting settings using ``make format-tests``.
+or later is required.  The configuration is in files ``.clang-format``
+in the respective folders.  Since the modifications from `clang-format`
+can be significant and - especially for "legacy style code" - also is
+not always improving readability, a large number of files currently have
+a ``// clang-format off`` at the top, which will disable the processing.
+Over time, files will be refactored and updated to that `clang-format`
+may be applied to them (at least in part).
+
+If `clang-format` is available, the source code files in the ``unittest``
+tree can be updated to conform to the formatting settings using
+``make format-tests`` and the files in ``src`` with ``make format-src``.

doc/src/Build_extras.rst

@@ -37,6 +37,7 @@ This is the list of packages that may require additional steps.
    * :ref:`KOKKOS <kokkos>`
    * :ref:`LATTE <latte>`
    * :ref:`MESSAGE <message>`
+   * :ref:`MLIAP <mliap>`
    * :ref:`MSCG <mscg>`
    * :ref:`OPT <opt>`
    * :ref:`POEMS <poems>`
@@ -47,10 +48,13 @@ This is the list of packages that may require additional steps.
    * :ref:`USER-AWPMD <user-awpmd>`
    * :ref:`USER-COLVARS <user-colvars>`
    * :ref:`USER-H5MD <user-h5md>`
+   * :ref:`USER-HDNNP <user-hdnnp>`
    * :ref:`USER-INTEL <user-intel>`
+   * :ref:`USER-MDI <user-mdi>`
    * :ref:`USER-MESONT <user-mesont>`
    * :ref:`USER-MOLFILE <user-molfile>`
    * :ref:`USER-NETCDF <user-netcdf>`
+   * :ref:`USER-PACE <user-pace>`
    * :ref:`USER-PLUMED <user-plumed>`
    * :ref:`USER-OMP <user-omp>`
    * :ref:`USER-QMMM <user-qmmm>`
@@ -119,21 +123,21 @@ CMake build
    -D GPU_API=value             # value = opencl (default) or cuda or hip
    -D GPU_PREC=value            # precision setting
                                 # value = double or mixed (default) or single
-   -D OCL_TUNE=value            # hardware choice for GPU_API=opencl
-                                # generic (default) or intel (Intel CPU) or fermi, kepler, cypress (NVIDIA)
    -D GPU_ARCH=value            # primary GPU hardware choice for GPU_API=cuda
                                 # value = sm_XX, see below
                                 # default is sm_50
    -D HIP_ARCH=value            # primary GPU hardware choice for GPU_API=hip
                                 # value depends on selected HIP_PLATFORM
-                                # default is 'gfx906' for HIP_PLATFORM=hcc and 'sm_50' for HIP_PLATFORM=nvcc
+                                # default is 'gfx906' for HIP_PLATFORM=amd and 'sm_50' for HIP_PLATFORM=nvcc
    -D HIP_USE_DEVICE_SORT=value # enables GPU sorting
                                 # value = yes (default) or no
-   -D CUDPP_OPT=value           # optimization setting for GPU_API=cuda
+   -D CUDPP_OPT=value           # use GPU binning on with CUDA (should be off for modern GPUs)
-                                # enables CUDA Performance Primitives Optimizations
+                                # enables CUDA Performance Primitives, must be "no" for CUDA_MPS_SUPPORT=yes
-                                # value = yes (default) or no
+                                # value = yes or no (default)
    -D CUDA_MPS_SUPPORT=value    # enables some tweaks required to run with active nvidia-cuda-mps daemon
                                 # value = yes or no (default)
+   -D USE_STATIC_OPENCL_LOADER=value  # downloads/includes OpenCL ICD loader library, no local OpenCL headers/libs needed
+                                      # value = yes (default) or no
 
 :code:`GPU_ARCH` settings for different GPU hardware is as follows:
 
@@ -160,19 +164,32 @@ When building with CMake, you **must NOT** build the GPU library in ``lib/gpu``
 using the traditional build procedure. CMake will detect files generated by that
 process and will terminate with an error and a suggestion for how to remove them.
 
+If you are compiling for OpenCL, the default setting is to download, build, and
+link with a static OpenCL ICD loader library and standard OpenCL headers.  This
+way no local OpenCL development headers or library needs to be present and only
+OpenCL compatible drivers need to be installed to use OpenCL.  If this is not
+desired, you can set :code:`USE_STATIC_OPENCL_LOADER` to :code:`no`.
+
 If you are compiling with HIP, note that before running CMake you will have to
 set appropriate environment variables. Some variables such as
-:code:`HCC_AMDGPU_TARGET` or :code:`CUDA_PATH` are necessary for :code:`hipcc`
+:code:`HCC_AMDGPU_TARGET` (for ROCm <= 4.0) or :code:`CUDA_PATH` are necessary for :code:`hipcc`
 and the linker to work correctly.
 
 .. code:: bash
 
-   # AMDGPU target
+   # AMDGPU target (ROCm <= 4.0)
    export HIP_PLATFORM=hcc
    export HCC_AMDGPU_TARGET=gfx906
    cmake -D PKG_GPU=on -D GPU_API=HIP -D HIP_ARCH=gfx906 -D CMAKE_CXX_COMPILER=hipcc ..
    make -j 4
 
+.. code:: bash
+
+   # AMDGPU target (ROCm >= 4.1)
+   export HIP_PLATFORM=amd
+   cmake -D PKG_GPU=on -D GPU_API=HIP -D HIP_ARCH=gfx906 -D CMAKE_CXX_COMPILER=hipcc ..
+   make -j 4
+
 .. code:: bash
 
    # CUDA target (not recommended, use GPU_ARCH=cuda)
@@ -218,11 +235,20 @@ Makefile if desired:
 * ``CUDA_PRECISION`` = precision (double, mixed, single)
 * ``EXTRAMAKE`` = which Makefile.lammps.\* file to copy to Makefile.lammps
 
-The file Makefile.linux_multi is set up to include support for multiple
+The file Makefile.cuda is set up to include support for multiple
 GPU architectures as supported by the CUDA toolkit in use. This is done
 through using the "--gencode " flag, which can be used multiple times and
 thus support all GPU architectures supported by your CUDA compiler.
 
+To enable GPU binning via CUDA performance primitives set the Makefile variable
+``CUDPP_OPT = -DUSE_CUDPP -Icudpp_mini``.  This should **not** be used with
+most modern GPUs.
+
+To support the CUDA multiprocessor server you can set the define
+``-DCUDA_PROXY``.  Please note that in this case you must **not** use
+the CUDA performance primitives and thus set the variable ``CUDPP_OPT``
+to empty.
+
 If the library build is successful, 3 files should be created:
 ``lib/gpu/libgpu.a``\ , ``lib/gpu/nvc_get_devices``\ , and
 ``lib/gpu/Makefile.lammps``\ .  The latter has settings that enable LAMMPS
@@ -249,18 +275,18 @@ To build with this package, the KIM library with API v2 must be downloaded
 and built on your system. It must include the KIM models that you want to
 use with LAMMPS.
 
-If you would like to use the :doc:`kim_query <kim_commands>`
+If you would like to use the :doc:`kim query <kim_commands>`
 command, you also need to have libcurl installed with the matching
 development headers and the curl-config tool.
 
-If you would like to use the :doc:`kim_property <kim_commands>`
+If you would like to use the :doc:`kim property <kim_commands>`
 command, you need to build LAMMPS with the PYTHON package installed
 and linked to Python 3.6 or later. See the :ref:`PYTHON package build info <python>`
 for more details on this. After successfully building LAMMPS with Python, you
-also need to install the kim-property Python package, which can be easily done using
+also need to install the ``kim-property`` Python package, which can be easily
-*pip* as ``pip install kim-property``, or from the *conda-forge* channel as
+done using *pip* as ``pip install kim-property``, or from the *conda-forge*
-``conda install kim-property`` if LAMMPS is built in Conda. More detailed
+channel as ``conda install kim-property`` if LAMMPS is built in Conda. More
-information is available at:
+detailed information is available at:
 `kim-property installation <https://github.com/openkim/kim-property#installing-kim-property>`_.
 
 In addition to installing the KIM API, it is also necessary to install the
@@ -282,6 +308,7 @@ minutes to hours) to build.  Of course you only need to do that once.)
          -D DOWNLOAD_KIM=value           # download OpenKIM API v2 for build, value = no (default) or yes
          -D LMP_DEBUG_CURL=value         # set libcurl verbose mode on/off, value = off (default) or on
          -D LMP_NO_SSL_CHECK=value       # tell libcurl to not verify the peer, value = no (default) or yes
+         -D KIM_EXTRA_UNITTESTS=value    # enables extra unit tests, value = no (default) or yes
 
       If ``DOWNLOAD_KIM`` is set to *yes* (or *on*), the KIM API library
       will be downloaded and built inside the CMake build directory.  If
@@ -290,11 +317,16 @@ minutes to hours) to build.  Of course you only need to do that once.)
       ``PKG_CONFIG_PATH`` environment variable so that libkim-api can be
       found, or run the command ``source kim-api-activate``.
 
+      Extra unit tests can only be available if they are explicitly requested
+      (``KIM_EXTRA_UNITTESTS`` is set to *yes* (or *on*)) and the prerequisites
+      are met. See :ref:`KIM Extra unit tests <kim_extra_unittests>` for
+      more details on this.
+
    .. tab:: Traditional make
 
       You can download and build the KIM library manually if you prefer;
       follow the instructions in ``lib/kim/README``.  You can also do
-      this in one step from the lammps/src dir, using a command like
+      this in one step from the lammps/src directory, using a command like
       these, which simply invoke the ``lib/kim/Install.py`` script with
       the specified args.
 
@@ -314,7 +346,7 @@ minutes to hours) to build.  Of course you only need to do that once.)
 
       .. code-block:: make
 
-         LMP_INC =       -DLMP_NO_SSL_CHECK
+         LMP_INC = -DLMP_NO_SSL_CHECK
 
 Debugging OpenKIM web queries in LAMMPS
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -338,6 +370,39 @@ specify your own CA cert path by setting the environment variable
 ``CURL_CA_BUNDLE`` to the path of your choice.  A call to the KIM web
 query would get this value from the environment variable.
 
+.. _kim_extra_unittests:
+
+KIM Extra unit tests (CMake only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+During development, testing, or debugging, if
+:doc:`unit testing <Build_development>` is enabled in LAMMPS, one can also
+enable extra tests on :doc:`KIM commands <kim_commands>` by setting the
+``KIM_EXTRA_UNITTESTS`` to *yes* (or *on*).
+
+Enabling the extra unit tests have some requirements,
+
+* It requires to have internet access.
+* It requires to have libcurl installed with the matching development headers
+  and the curl-config tool.
+* It requires to build LAMMPS with the PYTHON package installed and linked to
+  Python 3.6 or later. See the :ref:`PYTHON package build info <python>` for
+  more details on this.
+* It requires to have ``kim-property`` Python package installed, which can be
+  easily done using *pip* as ``pip install kim-property``, or from the
+  *conda-forge* channel as ``conda install kim-property`` if LAMMPS is built in
+  Conda. More detailed information is available at:
+  `kim-property installation <https://github.com/openkim/kim-property#installing-kim-property>`_.
+* It is also necessary to install
+  ``EAM_Dynamo_MendelevAckland_2007v3_Zr__MO_004835508849_000``,
+  ``EAM_Dynamo_ErcolessiAdams_1994_Al__MO_123629422045_005``, and
+  ``LennardJones612_UniversalShifted__MO_959249795837_003`` KIM models.
+  See `Obtaining KIM Models <http://openkim.org/doc/usage/obtaining-models>`_
+  to learn how to install a pre-built binary of the OpenKIM Repository of
+  Models or see
+  `Installing KIM Models <https://openkim.org/doc/usage/obtaining-models/#installing_models>`_
+  to learn how to install the specific KIM models.
+
 ----------
 
 .. _kokkos:
@@ -392,6 +457,9 @@ They must be specified in uppercase.
    *  - ZEN2
       - HOST
       - AMD Zen2 class CPU (AVX 2)
+   *  - ZEN3
+      - HOST
+      - AMD Zen3 class CPU (AVX 2)
    *  - ARMV80
       - HOST
       - ARMv8.0 Compatible CPU
@@ -404,6 +472,9 @@ They must be specified in uppercase.
    *  - ARMV8_THUNDERX2
       - HOST
       - ARMv8 Cavium ThunderX2 CPU
+   *  - A64FX
+      - HOST
+      - ARMv8.2 with SVE Support
    *  - WSM
       - HOST
       - Intel Westmere CPU (SSE 4.2)
@@ -476,17 +547,23 @@ They must be specified in uppercase.
    *  - AMPERE80
       - GPU
       - NVIDIA Ampere generation CC 8.0 GPU
+   *  - AMPERE86
+      - GPU
+      - NVIDIA Ampere generation CC 8.6 GPU
    *  - VEGA900
       - GPU
       - AMD GPU MI25 GFX900
    *  - VEGA906
       - GPU
       - AMD GPU MI50/MI60 GFX906
+   *  - VEGA908
+      - GPU
+      - AMD GPU MI100 GFX908
    *  - INTEL_GEN
       - GPU
       - Intel GPUs Gen9+
 
-This list was last updated for version 3.2 of the Kokkos library.
+This list was last updated for version 3.4.1 of the Kokkos library.
 
 .. tabs::
 
@@ -732,6 +809,54 @@ be installed on your system.
 
 ----------
 
+.. _mliap:
+
+MLIAP package
+---------------------------
+
+Building the MLIAP package requires including the :ref:`SNAP <PKG-SNAP>`
+package.  There will be an error message if this requirement is not satisfied.
+Using the *mliappy* model also requires enabling Python support, which
+in turn requires the :ref:`PYTHON <PKG-PYTHON>`
+package **and** requires you have the `cython <https://cython.org>`_ software
+installed and with it a working ``cythonize`` command.  This feature requires
+compiling LAMMPS with Python version 3.6 or later.
+
+.. tabs::
+
+   .. tab:: CMake build
+
+      .. code-block:: bash
+
+         -D MLIAP_ENABLE_PYTHON=value   # enable mliappy model (default is autodetect)
+
+      Without this setting, CMake will check whether it can find a
+      suitable Python version and the ``cythonize`` command and choose
+      the default accordingly.  During the build procedure the provided
+      .pyx file(s) will be automatically translated to C++ code and compiled.
+      Please do **not** run ``cythonize`` manually in the ``src/MLIAP`` folder,
+      as that can lead to compilation errors if Python support is not enabled.
+      If you did by accident, please remove the generated .cpp and .h files.
+
+   .. tab:: Traditional make
+
+      The build uses the ``lib/python/Makefile.mliap_python`` file in the
+      compile/link process to add a rule to update the files generated by
+      the ``cythonize`` command in case the corresponding .pyx file(s) were
+      modified.  You may need to modify ``lib/python/Makefile.lammps``
+      if the LAMMPS build fails.
+      To manually enforce building MLIAP with Python support enabled,
+      you can add
+      ``-DMLIAP_PYTHON`` to the ``LMP_INC`` variable in your machine makefile.
+      You may have to manually run the ``cythonize`` command on .pyx file(s)
+      in the ``src`` folder, if this is not automatically done during
+      installing the MLIAP package.  Please do **not** run ``cythonize``
+      in the ``src/MLIAP`` folder, as that can lead to compilation errors
+      if Python support is not enabled.
+      If you did by accident, please remove the generated .cpp and .h files.
+
+----------
+
 .. _mscg:
 
 MSCG package
@@ -1134,6 +1259,46 @@ be built for the most part with all major versions of the C++ language.
 
 ----------
 
+.. _user-pace:
+
+USER-PACE package
+-----------------------------
+
+This package requires a library that can be downloaded and built
+in lib/pace or somewhere else, which must be done before building
+LAMMPS with this package. The code for the library can be found
+at: `https://github.com/ICAMS/lammps-user-pace/ <https://github.com/ICAMS/lammps-user-pace/>`_
+
+.. tabs::
+
+   .. tab:: CMake build
+
+      By default the library will be downloaded from the git repository
+      and built automatically when the USER-PACE package is enabled with
+      ``-D PKG_USER-PACE=yes``.  The location for the sources may be
+      customized by setting the variable ``PACELIB_URL`` when
+      configuring with CMake (e.g. to use a local archive on machines
+      without internet access).  Since CMake checks the validity of the
+      archive with ``md5sum`` you may also need to set ``PACELIB_MD5``
+      if you provide a different library version than what is downloaded
+      automatically.
+
+
+   .. tab:: Traditional make
+
+      You can download and build the USER-PACE library
+      in one step from the ``lammps/src`` dir, using these commands,
+      which invoke the ``lib/pace/Install.py`` script.
+
+      .. code-block:: bash
+
+         $ make lib-pace                          # print help message
+         $ make lib-pace args="-b"                # download and build the default version in lib/pace
+
+      You should not need to edit the ``lib/pace/Makefile.lammps`` file.
+
+----------
+
 .. _user-plumed:
 
 USER-PLUMED package
@@ -1309,6 +1474,60 @@ the HDF5 library.
 
 ----------
 
+.. _user-hdnnp:
+
+USER-HDNNP package
+---------------------------------
+
+To build with the USER-HDNNP package it is required to download and build the
+external `n2p2 <https://github.com/CompPhysVienna/n2p2>`__ library ``v2.1.4``
+(or higher). The LAMMPS build process offers an automatic download and
+compilation of *n2p2* or allows you to choose the installation directory of
+*n2p2* manually. Please see the boxes below for the CMake and traditional build
+system for detailed information.
+
+In case of a manual installation of *n2p2* you only need to build the *n2p2* core
+library ``libnnp`` and interface library ``libnnpif``. When using GCC it should
+suffice to execute ``make libnnpif`` in the *n2p2* ``src`` directory. For more
+details please see ``lib/hdnnp/README`` and the `n2p2 build documentation
+<https://compphysvienna.github.io/n2p2/topics/build.html>`__.
+
+.. tabs::
+
+   .. tab:: CMake build
+
+      .. code-block:: bash
+
+         -D DOWNLOAD_N2P2=value    # download n2p2 for build, value = no (default) or yes
+         -D N2P2_DIR=path          # n2p2 base directory (only needed if a custom location)
+
+      If ``DOWNLOAD_N2P2`` is set, the *n2p2* library will be downloaded and
+      built inside the CMake build directory.  If the *n2p2* library is already
+      on your system (in a location CMake cannot find it), set the ``N2P2_DIR``
+      to path where *n2p2* is located. If *n2p2* is located directly in
+      ``lib/hdnnp/n2p2`` it will be automatically found by CMake.
+
+   .. tab:: Traditional make
+
+      You can download and build the *n2p2* library manually if you prefer;
+      follow the instructions in ``lib/hdnnp/README``\ . You can also do it in
+      one step from the ``lammps/src`` dir, using a command like these, which
+      simply invoke the ``lib/hdnnp/Install.py`` script with the specified args:
+
+      .. code-block:: bash
+
+         $ make lib-hdnnp             # print help message
+         $ make lib-hdnnp args="-b"   # download and build in lib/hdnnp/n2p2-...
+         $ make lib-hdnnp args="-b -v 2.1.4" # download and build specific version
+         $ make lib-hdnnp args="-p /usr/local/n2p2" # use the existing n2p2 installation in /usr/local/n2p2
+
+      Note that 3 symbolic (soft) links, ``includelink``, ``liblink`` and
+      ``Makefile.lammps``, will be created in ``lib/hdnnp`` to point to
+      ``n2p2/include``, ``n2p2/lib`` and ``n2p2/lib/Makefile.lammps-extra``,
+      respectively. When LAMMPS is built in ``src`` it will use these links.
+
+----------
+
 .. _user-intel:
 
 USER-INTEL package
@@ -1379,6 +1598,35 @@ TBB and MKL.
 
 ----------
 
+.. _user-mdi:
+
+USER-MDI package
+-----------------------------
+
+.. tabs::
+
+   .. tab:: CMake build
+
+      .. code-block:: bash
+
+         -D DOWNLOAD_MDI=value    # download MDI Library for build, value = no (default) or yes
+
+   .. tab:: Traditional make
+
+      Before building LAMMPS, you must build the MDI Library in
+      ``lib/mdi``\ .  You can do this by executing a command like one
+      of the following from the ``lib/mdi`` directory:
+
+      .. code-block:: bash
+
+         $ python Install.py -m gcc       # build using gcc compiler
+         $ python Install.py -m icc       # build using icc compiler
+
+      The build should produce two files: ``lib/mdi/includelink/mdi.h``
+      and ``lib/mdi/liblink/libmdi.so``\ .
+
+----------
+
 .. _user-mesont:
 
 USER-MESONT package

doc/src/Build_link.rst

@@ -20,16 +20,8 @@ the suffix ``.so.0`` (or some other number).
 .. note::
 
    Care should be taken to use the same MPI library for the calling code
-   and the LAMMPS library.  The ``library.h`` file includes ``mpi.h``
+   and the LAMMPS library unless LAMMPS is to be compiled without (real)
-   and uses definitions from it so those need to be available and
+   MPI support using the include STUBS MPI library.
-   consistent.  When LAMMPS is compiled with the included STUBS MPI
-   library, then its ``mpi.h`` file needs to be included.  While it is
-   technically possible to use a full MPI library in the calling code
-   and link to a serial LAMMPS library compiled with MPI STUBS, it is
-   recommended to use the *same* MPI library for both, and then use
-   ``MPI_Comm_split()`` in the calling code to pass a suitable
-   communicator with a subset of MPI ranks to the function creating the
-   LAMMPS instance.
 
 Link with LAMMPS as a static library
 ------------------------------------
@@ -110,7 +102,7 @@ executable, that are also required to link the LAMMPS executable.
 
       .. code-block:: bash
 
-         gcc -c -O -I${HOME}/lammps/src/STUBS -I${HOME}/lammps/src -caller.c
+         gcc -c -O -I${HOME}/lammps/src -caller.c
          g++ -o caller caller.o -L${HOME}/lammps/lib/poems \
                       -L${HOME}/lammps/src/STUBS -L${HOME}/lammps/src \
                       -llammps_serial -lpoems -lmpi_stubs
@@ -174,7 +166,7 @@ the POEMS package installed becomes:
 
       .. code-block:: bash
 
-         gcc -c -O -I${HOME}/lammps/src/STUBS -I${HOME}/lammps/src -caller.c
+         gcc -c -O -I${HOME}/lammps/src -caller.c
          g++ -o caller caller.o -L${HOME}/lammps/src -llammps_serial
 
 Locating liblammps.so at runtime

doc/src/Build_manual.rst

@@ -28,29 +28,18 @@ If you downloaded LAMMPS as a tarball from `the LAMMPS website <lws_>`_,
 the html folder and the PDF files should be included.
 
 If you downloaded LAMMPS from the public git repository, then the HTML
-and PDF files are not included.  Instead you need to create them, in one
+and PDF files are not included.  You can build the HTML or PDF files yourself,
-of two ways:
+by typing ``make html``  or ``make pdf`` in the ``doc`` folder.  This requires
-
+various tools and files.  Some of them have to be installed (see below).  For
-a. You can "fetch" the current HTML and PDF files from the LAMMPS web
+the rest the build process will attempt to download and install them into
-   site.  Just type ``make fetch``.  This should download a ``html_www``
+a python virtual environment and local folders.
-   directory and a ``Manual_www.pdf`` file.  Note that if new LAMMPS features
-   have been added more recently than the date of your LAMMPS version, the
-   fetched documentation will include those changes (but your source code
-   will not, unless you update your local repository).
-
-b. You can build the HTML or PDF files yourself, by typing ``make html``
-   or ``make pdf`` in the ``doc`` folder.  This requires various tools
-   and files.  Some of them have to be installed (see below).  For the
-   rest the build process will attempt to download and install them into
-   a python virtual environment and local folders.
 
 A current version of the manual (latest patch release, aka unstable
 branch) is is available online at:
-`https://lammps.sandia.gov/doc/Manual.html
+`https://docs.lammps.org/Manual.html <https://docs.lammps.org/Manual.html>`_.
-<https://lammps.sandia.gov/doc/Manual.html>`_ A version of the manual
+A version of the manual corresponding to the ongoing development (aka master branch)
-corresponding to the ongoing development (aka master branch) is
+is available online at: `https://docs.lammps.org/latest/
-available online at: `https://docs.lammps.org/
+<https://docs.lammps.org/latest/>`_
-<https://docs.lammps.org/>`_
 
 Build using GNU make
 --------------------
@@ -74,7 +63,11 @@ For the documentation build a python virtual environment is set up in
 the folder ``doc/docenv`` and various python packages are installed into
 that virtual environment via the ``pip`` tool.  For rendering embedded
 LaTeX code also the `MathJax <https://www.mathjax.org/>`_ JavaScript
-engine needs to be downloaded.
+engine needs to be downloaded.  If you need to pass additional options
+to the pip commands to work (e.g. to use a web proxy or to point to
+additional SSL certificates) you can set them via the ``PIP_OPTIONS``
+environment variable or uncomment and edit the ``PIP_OPTIONS`` setting
+at beginning of the makefile.
 
 The actual translation is then done via ``make`` commands in the doc
 folder.  The following ``make`` commands are available:
@@ -108,7 +101,10 @@ installation of the HTML manual pages into the "install" step when
 installing LAMMPS after the CMake build via ``cmake --build . --target
 install``.  The documentation build is included in the default build
 target, but can also be requested independently with
-``cmake --build . --target doc``.
+``cmake --build . --target doc``.  If you need to pass additional options
+to the pip commands to work (e.g. to use a web proxy or to point to
+additional SSL certificates) you can set them via the ``PIP_OPTIONS``
+environment variable.
 
 .. code-block:: bash
 
@@ -250,4 +246,4 @@ the file ``lammps/doc/utils/sphinx-config/false_positives.txt``.
 
 .. _rst: https://docutils.readthedocs.io/en/sphinx-docs/user/rst/quickstart.html
 
-.. _lws: https://lammps.sandia.gov
+.. _lws: https://www.lammps.org

doc/src/Build_package.rst

@@ -30,17 +30,17 @@ steps, as explained on the :doc:`Build extras <Build_extras>` page.
 These links take you to the extra instructions for those select
 packages:
 
-+----------------------------------+----------------------------------+------------------------------------+------------------------------+--------------------------------+--------------------------------------+
++--------------------------------------+--------------------------------------+------------------------------------+----------------------------------+--------------------------------+--------------------------------+
-| :ref:`COMPRESS <compress>`       | :ref:`GPU <gpu>`                 | :ref:`KIM <kim>`                   | :ref:`KOKKOS <kokkos>`       | :ref:`LATTE <latte>`           | :ref:`MESSAGE <message>`             |
+| :ref:`COMPRESS <compress>`           | :ref:`GPU <gpu>`                     | :ref:`KIM <kim>`                   | :ref:`KOKKOS <kokkos>`           | :ref:`LATTE <latte>`           | :ref:`MESSAGE <message>`       |
-+----------------------------------+----------------------------------+------------------------------------+------------------------------+--------------------------------+--------------------------------------+
++--------------------------------------+--------------------------------------+------------------------------------+----------------------------------+--------------------------------+--------------------------------+
-| :ref:`MSCG <mscg>`               | :ref:`OPT <opt>`                 | :ref:`POEMS <poems>`               | :ref:`PYTHON <python>`       | :ref:`VORONOI <voronoi>`       | :ref:`USER-ADIOS <user-adios>`       |
+| :ref:`MSCG <mscg>`                   | :ref:`OPT <opt>`                     | :ref:`POEMS <poems>`               | :ref:`PYTHON <python>`           | :ref:`VORONOI <voronoi>`       | :ref:`USER-ADIOS <user-adios>` |
-+----------------------------------+----------------------------------+------------------------------------+------------------------------+--------------------------------+--------------------------------------+
++--------------------------------------+--------------------------------------+------------------------------------+----------------------------------+--------------------------------+--------------------------------+
-| :ref:`USER-ATC <user-atc>`       | :ref:`USER-AWPMD <user-awpmd>`   | :ref:`USER-COLVARS <user-colvars>` | :ref:`USER-H5MD <user-h5md>` | :ref:`USER-INTEL <user-intel>` | :ref:`USER-MOLFILE <user-molfile>`   |
+| :ref:`USER-ATC <user-atc>`           | :ref:`USER-AWPMD <user-awpmd>`       | :ref:`USER-COLVARS <user-colvars>` | :ref:`USER-H5MD <user-h5md>`     | :ref:`USER-HDNNP <user-hdnnp>` | :ref:`USER-INTEL <user-intel>` |
-+----------------------------------+----------------------------------+------------------------------------+------------------------------+--------------------------------+--------------------------------------+
++--------------------------------------+--------------------------------------+------------------------------------+----------------------------------+--------------------------------+--------------------------------+
-| :ref:`USER-NETCDF <user-netcdf>` | :ref:`USER-PLUMED <user-plumed>` | :ref:`USER-OMP <user-omp>`         | :ref:`USER-QMMM <user-qmmm>` | :ref:`USER-QUIP <user-quip>`   | :ref:`USER-SCAFACOS <user-scafacos>` |
+| :ref:`USER-MOLFILE <user-molfile>`   | :ref:`USER-NETCDF <user-netcdf>`     | :ref:`USER-PACE <user-pace>`       | :ref:`USER-PLUMED <user-plumed>` | :ref:`USER-OMP <user-omp>`     | :ref:`USER-QMMM <user-qmmm>`   |
-+----------------------------------+----------------------------------+------------------------------------+------------------------------+--------------------------------+--------------------------------------+
++--------------------------------------+--------------------------------------+------------------------------------+----------------------------------+--------------------------------+--------------------------------+
-| :ref:`USER-SMD <user-smd>`       | :ref:`USER-VTK <user-vtk>`       |                                    |                              |                                |                                      |
+| :ref:`USER-QUIP <user-quip>`         | :ref:`USER-SCAFACOS <user-scafacos>` | :ref:`USER-SMD <user-smd>`         | :ref:`USER-VTK <user-vtk>`       |                                |                                |
-+----------------------------------+----------------------------------+------------------------------------+------------------------------+--------------------------------+--------------------------------------+
++--------------------------------------+--------------------------------------+------------------------------------+----------------------------------+--------------------------------+--------------------------------+
 
 The mechanism for including packages is simple but different for CMake
 versus make.
@@ -160,6 +160,7 @@ one of them as a starting point and customize it to your needs.
     cmake -C ../cmake/presets/clang.cmake    [OPTIONS] ../cmake  # change settings to use the Clang compilers by default
     cmake -C ../cmake/presets/gcc.cmake      [OPTIONS] ../cmake  # change settings to use the GNU compilers by default
     cmake -C ../cmake/presets/intel.cmake    [OPTIONS] ../cmake  # change settings to use the Intel compilers by default
+    cmake -C ../cmake/presets/pgi.cmake      [OPTIONS] ../cmake  # change settings to use the PGI compilers by default
     cmake -C ../cmake/presets/all_on.cmake   [OPTIONS] ../cmake  # enable all packages
     cmake -C ../cmake/presets/all_off.cmake  [OPTIONS] ../cmake  # disable all packages
     mingw64-cmake -C ../cmake/presets/mingw-cross.cmake [OPTIONS] ../cmake  #  compile with MinGW cross compilers

doc/src/Commands_all.rst

@@ -60,17 +60,14 @@ An alphabetic list of all general LAMMPS commands.
    * :doc:`include <include>`
    * :doc:`info <info>`
    * :doc:`jump <jump>`
-   * :doc:`kim_init <kim_commands>`
+   * :doc:`kim <kim_commands>`
-   * :doc:`kim_interactions <kim_commands>`
-   * :doc:`kim_param <kim_commands>`
-   * :doc:`kim_property <kim_commands>`
-   * :doc:`kim_query <kim_commands>`
    * :doc:`kspace_modify <kspace_modify>`
    * :doc:`kspace_style <kspace_style>`
    * :doc:`label <label>`
    * :doc:`lattice <lattice>`
    * :doc:`log <log>`
    * :doc:`mass <mass>`
+   * :doc:`mdi/engine <mdi_engine>`
    * :doc:`message <message>`
    * :doc:`minimize <minimize>`
    * :doc:`min_modify <min_modify>`
@@ -90,6 +87,7 @@ An alphabetic list of all general LAMMPS commands.
    * :doc:`pair_style <pair_style>`
    * :doc:`pair_write <pair_write>`
    * :doc:`partition <partition>`
+   * :doc:`plugin <plugin>`
    * :doc:`prd <prd>`
    * :doc:`print <print>`
    * :doc:`processors <processors>`

doc/src/Commands_bond.rst

@@ -35,6 +35,7 @@ OPT.
    * :doc:`class2 (ko) <bond_class2>`
    * :doc:`fene (iko) <bond_fene>`
    * :doc:`fene/expand (o) <bond_fene_expand>`
+   * :doc:`gaussian <bond_gaussian>`
    * :doc:`gromos (o) <bond_gromos>`
    * :doc:`harmonic (iko) <bond_harmonic>`
    * :doc:`harmonic/shift (o) <bond_harmonic_shift>`
@@ -84,6 +85,7 @@ OPT.
    * :doc:`dipole (o) <angle_dipole>`
    * :doc:`fourier (o) <angle_fourier>`
    * :doc:`fourier/simple (o) <angle_fourier_simple>`
+   * :doc:`gaussian <angle_gaussian>` - multicentered Gaussian-based angle potential
    * :doc:`harmonic (iko) <angle_harmonic>`
    * :doc:`mm3 <angle_mm3>`
    * :doc:`quartic (o) <angle_quartic>`
@@ -124,7 +126,7 @@ OPT.
    * :doc:`quadratic (o) <dihedral_quadratic>`
    * :doc:`spherical <dihedral_spherical>`
    * :doc:`table (o) <dihedral_table>`
-   * :doc:`table/cut <dihedral_table_cut>`
+   * :doc:`table/cut <dihedral_table>`
 
 .. _improper:
 

doc/src/Commands_compute.rst

@@ -47,11 +47,13 @@ KOKKOS, o = USER-OMP, t = OPT.
    * :doc:`dihedral <compute_dihedral>`
    * :doc:`dihedral/local <compute_dihedral_local>`
    * :doc:`dilatation/atom <compute_dilatation_atom>`
+   * :doc:`dipole <compute_dipole>`
    * :doc:`dipole/chunk <compute_dipole_chunk>`
    * :doc:`displace/atom <compute_displace_atom>`
    * :doc:`dpd <compute_dpd>`
    * :doc:`dpd/atom <compute_dpd_atom>`
    * :doc:`edpd/temp/atom <compute_edpd_temp_atom>`
+   * :doc:`efield/atom <compute_efield_atom>`
    * :doc:`entropy/atom <compute_entropy_atom>`
    * :doc:`erotate/asphere <compute_erotate_asphere>`
    * :doc:`erotate/rigid <compute_erotate_rigid>`

doc/src/Commands_fix.rst

@@ -39,6 +39,9 @@ OPT.
    * :doc:`ave/time <fix_ave_time>`
    * :doc:`aveforce <fix_aveforce>`
    * :doc:`balance <fix_balance>`
+   * :doc:`brownian <fix_brownian>`
+   * :doc:`brownian/asphere <fix_brownian>`
+   * :doc:`brownian/sphere <fix_brownian>`
    * :doc:`bocs <fix_bocs>`
    * :doc:`bond/break <fix_bond_break>`
    * :doc:`bond/create <fix_bond_create>`
@@ -46,6 +49,7 @@ OPT.
    * :doc:`bond/react <fix_bond_react>`
    * :doc:`bond/swap <fix_bond_swap>`
    * :doc:`box/relax <fix_box_relax>`
+   * :doc:`charge/regulation <fix_charge_regulation>`
    * :doc:`client/md <fix_client_md>`
    * :doc:`cmap <fix_cmap>`
    * :doc:`colvars <fix_colvars>`
@@ -62,6 +66,7 @@ OPT.
    * :doc:`efield <fix_efield>`
    * :doc:`ehex <fix_ehex>`
    * :doc:`electron/stopping <fix_electron_stopping>`
+   * :doc:`electron/stopping/fit <fix_electron_stopping>`
    * :doc:`enforce2d (k) <fix_enforce2d>`
    * :doc:`eos/cv <fix_eos_cv>`
    * :doc:`eos/table <fix_eos_table>`
@@ -96,6 +101,7 @@ OPT.
    * :doc:`lb/viscous <fix_lb_viscous>`
    * :doc:`lineforce <fix_lineforce>`
    * :doc:`manifoldforce <fix_manifoldforce>`
+   * :doc:`mdi/engine <fix_mdi_engine>`
    * :doc:`meso/move <fix_meso_move>`
    * :doc:`momentum (k) <fix_momentum>`
    * :doc:`momentum/chunk <fix_momentum>`
@@ -113,7 +119,7 @@ OPT.
    * :doc:`nph/eff <fix_nh_eff>`
    * :doc:`nph/sphere (o) <fix_nph_sphere>`
    * :doc:`nphug <fix_nphug>`
-   * :doc:`npt (iko) <fix_nh>`
+   * :doc:`npt (giko) <fix_nh>`
    * :doc:`npt/asphere (o) <fix_npt_asphere>`
    * :doc:`npt/body <fix_npt_body>`
    * :doc:`npt/cauchy <fix_npt_cauchy>`
@@ -121,8 +127,8 @@ OPT.
    * :doc:`npt/sphere (o) <fix_npt_sphere>`
    * :doc:`npt/uef <fix_nh_uef>`
    * :doc:`numdiff <fix_numdiff>`
-   * :doc:`nve (iko) <fix_nve>`
+   * :doc:`nve (giko) <fix_nve>`
-   * :doc:`nve/asphere (i) <fix_nve_asphere>`
+   * :doc:`nve/asphere (gi) <fix_nve_asphere>`
    * :doc:`nve/asphere/noforce <fix_nve_asphere_noforce>`
    * :doc:`nve/awpmd <fix_nve_awpmd>`
    * :doc:`nve/body <fix_nve_body>`
@@ -137,7 +143,7 @@ OPT.
    * :doc:`nve/spin <fix_nve_spin>`
    * :doc:`nve/tri <fix_nve_tri>`
    * :doc:`nvk <fix_nvk>`
-   * :doc:`nvt (iko) <fix_nh>`
+   * :doc:`nvt (giko) <fix_nh>`
    * :doc:`nvt/asphere (o) <fix_nvt_asphere>`
    * :doc:`nvt/body <fix_nvt_body>`
    * :doc:`nvt/eff <fix_nh_eff>`
@@ -156,6 +162,9 @@ OPT.
    * :doc:`planeforce <fix_planeforce>`
    * :doc:`plumed <fix_plumed>`
    * :doc:`poems <fix_poems>`
+   * :doc:`polarize/bem/gmres <fix_polarize>`
+   * :doc:`polarize/bem/icc <fix_polarize>`
+   * :doc:`polarize/functional <fix_polarize>`
    * :doc:`pour <fix_pour>`
    * :doc:`precession/spin <fix_precession_spin>`
    * :doc:`press/berendsen <fix_press_berendsen>`
@@ -195,7 +204,7 @@ OPT.
    * :doc:`saed/vtk <fix_saed_vtk>`
    * :doc:`setforce (k) <fix_setforce>`
    * :doc:`setforce/spin <fix_setforce>`
-   * :doc:`shake <fix_shake>`
+   * :doc:`shake (k) <fix_shake>`
    * :doc:`shardlow (k) <fix_shardlow>`
    * :doc:`smd <fix_smd>`
    * :doc:`smd/adjust_dt <fix_smd_adjust_dt>`
@@ -220,6 +229,8 @@ OPT.
    * :doc:`temp/rescale <fix_temp_rescale>`
    * :doc:`temp/rescale/eff <fix_temp_rescale_eff>`
    * :doc:`tfmc <fix_tfmc>`
+   * :doc:`tgnpt/drude <fix_tgnh_drude>`
+   * :doc:`tgnvt/drude <fix_tgnh_drude>`
    * :doc:`thermal/conductivity <fix_thermal_conductivity>`
    * :doc:`ti/spring <fix_ti_spring>`
    * :doc:`tmd <fix_tmd>`

doc/src/Commands_kspace.rst

@@ -28,6 +28,7 @@ OPT.
    * :doc:`ewald/dipole/spin <kspace_style>`
    * :doc:`msm (o) <kspace_style>`
    * :doc:`msm/cg (o) <kspace_style>`
+   * :doc:`msm/dielectric <kspace_style>`
    * :doc:`pppm (giko) <kspace_style>`
    * :doc:`pppm/cg (o) <kspace_style>`
    * :doc:`pppm/dipole <kspace_style>`
@@ -36,4 +37,5 @@ OPT.
    * :doc:`pppm/disp/tip4p (o) <kspace_style>`
    * :doc:`pppm/stagger <kspace_style>`
    * :doc:`pppm/tip4p (o) <kspace_style>`
+   * :doc:`pppm/dielectric <kspace_style>`
    * :doc:`scafacos <kspace_style>`

doc/src/Commands_pair.rst

@@ -26,6 +26,7 @@ OPT.
    * :doc:`zero <pair_zero>`
    * :doc:`hybrid (k) <pair_hybrid>`
    * :doc:`hybrid/overlay (k) <pair_hybrid>`
+   * :doc:`hybrid/scaled <pair_hybrid>`
    * :doc:`kim <pair_kim>`
    * :doc:`list <pair_list>`
    *
@@ -33,7 +34,6 @@ OPT.
    *
    *
    *
-   *
    * :doc:`adp (o) <pair_adp>`
    * :doc:`agni (o) <pair_agni>`
    * :doc:`airebo (io) <pair_airebo>`
@@ -69,12 +69,15 @@ OPT.
    * :doc:`comb3 <pair_comb>`
    * :doc:`cosine/squared <pair_cosine_squared>`
    * :doc:`coul/cut (gko) <pair_coul>`
+   * :doc:`coul/cut/dielectric <pair_dielectric>`
+   * :doc:`coul/cut/global (o) <pair_coul>`
    * :doc:`coul/cut/soft (o) <pair_fep_soft>`
    * :doc:`coul/debye (gko) <pair_coul>`
    * :doc:`coul/diel (o) <pair_coul_diel>`
    * :doc:`coul/dsf (gko) <pair_coul>`
    * :doc:`coul/long (gko) <pair_coul>`
    * :doc:`coul/long/cs (g) <pair_cs>`
+   * :doc:`coul/long/dielectric <pair_dielectric>`
    * :doc:`coul/long/soft (o) <pair_fep_soft>`
    * :doc:`coul/msm (o) <pair_coul>`
    * :doc:`coul/slater/cut <pair_coul_slater>`
@@ -86,6 +89,8 @@ OPT.
    * :doc:`coul/wolf/cs <pair_cs>`
    * :doc:`dpd (gio) <pair_dpd>`
    * :doc:`dpd/fdt <pair_dpd_fdt>`
+   * :doc:`dpd/ext <pair_dpd_ext>`
+   * :doc:`dpd/ext/tstat <pair_dpd_ext>`
    * :doc:`dpd/fdt/energy (k) <pair_dpd_fdt>`
    * :doc:`dpd/tstat (go) <pair_dpd>`
    * :doc:`dsmc <pair_dsmc>`
@@ -96,6 +101,7 @@ OPT.
    * :doc:`eam/cd <pair_eam>`
    * :doc:`eam/cd/old <pair_eam>`
    * :doc:`eam/fs (gikot) <pair_eam>`
+   * :doc:`eam/he <pair_eam>`
    * :doc:`edip (o) <pair_edip>`
    * :doc:`edip/multi <pair_edip>`
    * :doc:`edpd <pair_mesodpd>`
@@ -114,6 +120,7 @@ OPT.
    * :doc:`gw/zbl <pair_gw>`
    * :doc:`hbond/dreiding/lj (o) <pair_hbond_dreiding>`
    * :doc:`hbond/dreiding/morse (o) <pair_hbond_dreiding>`
+   * :doc:`hdnnp <pair_hdnnp>`
    * :doc:`ilp/graphene/hbn <pair_ilp_graphene_hbn>`
    * :doc:`kolmogorov/crespi/full <pair_kolmogorov_crespi_full>`
    * :doc:`kolmogorov/crespi/z <pair_kolmogorov_crespi_z>`
@@ -121,7 +128,7 @@ OPT.
    * :doc:`lebedeva/z <pair_lebedeva_z>`
    * :doc:`lennard/mdf <pair_mdf>`
    * :doc:`line/lj <pair_line_lj>`
-   * :doc:`lj/charmm/coul/charmm (iko) <pair_charmm>`
+   * :doc:`lj/charmm/coul/charmm (giko) <pair_charmm>`
    * :doc:`lj/charmm/coul/charmm/implicit (ko) <pair_charmm>`
    * :doc:`lj/charmm/coul/long (gikot) <pair_charmm>`
    * :doc:`lj/charmm/coul/long/soft (o) <pair_fep_soft>`
@@ -138,13 +145,17 @@ OPT.
    * :doc:`lj/cubic (go) <pair_lj_cubic>`
    * :doc:`lj/cut (gikot) <pair_lj>`
    * :doc:`lj/cut/coul/cut (gko) <pair_lj_cut_coul>`
+   * :doc:`lj/cut/coul/cut/dielectric (o) <pair_dielectric>`
    * :doc:`lj/cut/coul/cut/soft (o) <pair_fep_soft>`
    * :doc:`lj/cut/coul/debye (gko) <pair_lj_cut_coul>`
+   * :doc:`lj/cut/coul/debye/dielectric <pair_dielectric>`
    * :doc:`lj/cut/coul/dsf (gko) <pair_lj_cut_coul>`
    * :doc:`lj/cut/coul/long (gikot) <pair_lj_cut_coul>`
    * :doc:`lj/cut/coul/long/cs <pair_cs>`
+   * :doc:`lj/cut/coul/long/dielectric (o) <pair_dielectric>`
    * :doc:`lj/cut/coul/long/soft (o) <pair_fep_soft>`
    * :doc:`lj/cut/coul/msm (go) <pair_lj_cut_coul>`
+   * :doc:`lj/cut/coul/msm/dielectric <pair_dielectric>`
    * :doc:`lj/cut/coul/wolf (o) <pair_lj_cut_coul>`
    * :doc:`lj/cut/dipole/cut (go) <pair_dipole>`
    * :doc:`lj/cut/dipole/long (g) <pair_dipole>`
@@ -159,14 +170,16 @@ OPT.
    * :doc:`lj/gromacs (gko) <pair_gromacs>`
    * :doc:`lj/gromacs/coul/gromacs (ko) <pair_gromacs>`
    * :doc:`lj/long/coul/long (iot) <pair_lj_long>`
+   * :doc:`lj/long/coul/long/dielectric <pair_dielectric>`
    * :doc:`lj/long/dipole/long <pair_dipole>`
    * :doc:`lj/long/tip4p/long (o) <pair_lj_long>`
    * :doc:`lj/mdf <pair_mdf>`
+   * :doc:`lj/relres (o) <pair_lj_relres>`
    * :doc:`lj/sdk (gko) <pair_sdk>`
    * :doc:`lj/sdk/coul/long (go) <pair_sdk>`
    * :doc:`lj/sdk/coul/msm (o) <pair_sdk>`
    * :doc:`lj/sf/dipole/sf (go) <pair_dipole>`
-   * :doc:`lj/smooth (o) <pair_lj_smooth>`
+   * :doc:`lj/smooth (go) <pair_lj_smooth>`
    * :doc:`lj/smooth/linear (o) <pair_lj_smooth_linear>`
    * :doc:`lj/switch3/coulgauss/long <pair_lj_switch3_coulgauss_long>`
    * :doc:`lj96/cut (go) <pair_lj96>`
@@ -185,7 +198,7 @@ OPT.
    * :doc:`mgpt <pair_mgpt>`
    * :doc:`mie/cut (g) <pair_mie>`
    * :doc:`mliap <pair_mliap>`
-   * :doc:`mm3/switch3/coulgauss/long <pair_mm3_switch3_coulgauss_long>`
+   * :doc:`mm3/switch3/coulgauss/long <pair_lj_switch3_coulgauss_long>`
    * :doc:`momb <pair_momb>`
    * :doc:`morse (gkot) <pair_morse>`
    * :doc:`morse/smooth/linear (o) <pair_morse>`
@@ -213,6 +226,7 @@ OPT.
    * :doc:`oxrna2/stk <pair_oxrna2>`
    * :doc:`oxrna2/xstk <pair_oxrna2>`
    * :doc:`oxrna2/coaxstk <pair_oxrna2>`
+   * :doc:`pace <pair_pace>`
    * :doc:`peri/eps <pair_peri>`
    * :doc:`peri/lps (o) <pair_peri>`
    * :doc:`peri/pmb (o) <pair_peri>`
@@ -220,6 +234,7 @@ OPT.
    * :doc:`polymorphic <pair_polymorphic>`
    * :doc:`python <pair_python>`
    * :doc:`quip <pair_quip>`
+   * :doc:`rann <pair_rann>`
    * :doc:`reax/c (ko) <pair_reaxc>`
    * :doc:`rebo (io) <pair_airebo>`
    * :doc:`resquared (go) <pair_resquared>`
@@ -241,6 +256,7 @@ OPT.
    * :doc:`spin/dipole/long <pair_spin_dipole>`
    * :doc:`spin/dmi <pair_spin_dmi>`
    * :doc:`spin/exchange <pair_spin_exchange>`
+   * :doc:`spin/exchange/biquadratic <pair_spin_exchange>`
    * :doc:`spin/magelec <pair_spin_magelec>`
    * :doc:`spin/neel <pair_spin_neel>`
    * :doc:`srp <pair_srp>`
@@ -261,6 +277,7 @@ OPT.
    * :doc:`ufm (got) <pair_ufm>`
    * :doc:`vashishta (gko) <pair_vashishta>`
    * :doc:`vashishta/table (o) <pair_vashishta>`
+   * :doc:`wf/cut <pair_wf_cut>`
    * :doc:`yukawa (gko) <pair_yukawa>`
    * :doc:`yukawa/colloid (go) <pair_yukawa_colloid>`
    * :doc:`zbl (gko) <pair_zbl>`

doc/src/Commands_parse.rst

@@ -162,3 +162,26 @@ LAMMPS:
    triple quotes can be nested in the usual manner.  See the doc pages
    for those commands for examples.  Only one of level of nesting is
    allowed, but that should be sufficient for most use cases.
+
+.. admonition:: ASCII versus UTF-8
+   :class: note
+
+   LAMMPS expects and processes 7-bit ASCII format text internally.
+   Many modern environments use UTF-8 encoding, which is a superset
+   of the 7-bit ASCII character table and thus mostly compatible.
+   However, there are several non-ASCII characters that can look
+   very similar to their ASCII equivalents or are invisible (so they
+   look like a blank), but are encoded differently.  Web browsers,
+   PDF viewers, document editors are known to sometimes replace one
+   with the other for a better looking output.  However, that can
+   lead to problems, for instance, when using cut-n-paste of input
+   file examples from web pages, or when using a document editor
+   (not a dedicated plain text editor) for writing LAMMPS inputs.
+   LAMMPS will try to detect this and substitute the non-ASCII
+   characters with their ASCII equivalents where known.  There also
+   is going to be a warning printed, if this occurs.  It is
+   recommended to avoid such characters altogether in LAMMPS input,
+   data and potential files.  The replacement tables are likely
+   incomplete and dependent on users reporting problems processing
+   correctly looking input containing UTF-8 encoded non-ASCII
+   characters.

doc/src/Developer.rst

@@ -13,5 +13,8 @@ of time and requests from the LAMMPS user community.
    Developer_org
    Developer_flow
    Developer_write
+   Developer_notes
+   Developer_plugins
+   Developer_unittest
    Classes
    Developer_utils

doc/src/Developer_notes.rst

@@ -0,0 +1,227 @@
+Notes for developers and code maintainers
+-----------------------------------------
+
+This section documents how some of the code functionality within
+LAMMPS works at a conceptual level.  Comments on code in source files
+typically document what a variable stores, what a small section of
+code does, or what a function does and its input/outputs.  The topics
+on this page are intended to document code functionality at a higher level.
+
+Fix contributions to instantaneous energy, virial, and cumulative energy
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Fixes can calculate contributions to the instantaneous energy and/or
+virial of the system, both in a global and peratom sense.  Fixes that
+perform thermostatting or barostatting can calculate the cumulative
+energy they add to or subtract from the system, which is accessed by
+the *ecouple* and *econserve* thermodynamic keywords.  This subsection
+explains how both work and what flags to set in a new fix to enable
+this functionality.
+
+Let's start with thermostatting and barostatting fixes.  Examples are
+the :doc:`fix langevin <fix_langevin>` and :doc:`fix npt <fix_nh>`
+commands.  Here is what the fix needs to do:
+
+* Set the variable *ecouple_flag* = 1 in the constructor.  Also set
+  *scalar_flag* = 1, *extscalar* = 1, and *global_freq* to a timestep
+  increment which matches how often the fix is invoked.
+* Implement a compute_scalar() method that returns the cumulative
+  energy added or subtracted by the fix, e.g. by rescaling the
+  velocity of atoms.  The sign convention is that subtracted energy is
+  positive, added energy is negative.  This must be the total energy
+  added to the entire system, i.e. an "extensive" quantity, not a
+  per-atom energy.  Cumulative means the summed energy since the fix
+  was instantiated, even across multiple runs.  This is because the
+  energy is used by the *econserve* thermodynamic keyword to check
+  that the fix is conserving the total energy of the system,
+  i.e. potential energy + kinetic energy + coupling energy = a
+  constant.
+
+And here is how the code operates:
+
+* The Modify class makes a list of all fixes that set *ecouple_flag* = 1.
+* The :doc:`thermo_style custom <thermo_style>` command defines
+  *ecouple* and *econserve* keywords.
+* These keywords sum the energy contributions from all the
+  *ecouple_flag* = 1 fixes by invoking the energy_couple() method in
+  the Modify class, which calls the compute_scalar() method of each
+  fix in the list.
+
+------------------
+
+Next, here is how a fix contributes to the instantaneous energy and
+virial of the system.  First, it sets any or all of these flags to a
+value of 1 in their constructor:
+
+* *energy_global_flag* to contribute to global energy, example: :doc:`fix indent <fix_indent>`
+* *energy_peratom_flag* to contribute to peratom energy, :doc:`fix cmap <fix_cmap>`
+* *virial_global_flag* to contribute to global virial, example: :doc:`fix wall <fix_wall>`
+* *virial_peratom_flag* to contribute to peratom virial, example: :doc:`fix wall <fix_wall>`
+
+The fix must also do the following:
+
+* For global energy, implement a compute_scalar() method that returns
+  the energy added or subtracted on this timestep.  Here the sign
+  convention is that added energy is positive, subtracted energy is
+  negative.
+* For peratom energy, invoke the ev_init(eflag,vflag) function each
+  time the fix is invoked, which initializes per-atom energy storage.
+  The value of eflag may need to be stored from an earlier call to the
+  fix during the same timestep.  See how the :doc:`fix cmap
+  <fix_cmap>` command does this in src/MOLECULE/fix_cmap.cpp.  When an
+  energy for one or more atoms is calculated, invoke the ev_tally()
+  function to tally the contribution to each atom.  Both the ev_init()
+  and ev_tally() methods are in the parent Fix class.
+* For global and/or peratom virial, invoke the v_init(vflag) function
+  each time the fix is invoked, which initializes virial storage.
+  When forces on one or more atoms are calculated, invoke the
+  v_tally() function to tally the contribution.  Both the v_init() and
+  v_tally() methods are in the parent Fix class.  Note that there are
+  several variants of v_tally(); choose the one appropriate to your
+  fix.
+
+.. note::
+
+   The ev_init() and ev_tally() methods also account for global and
+   peratom virial contributions.  Thus you do not need to invoke the
+   v_init() and v_tally() methods, if the fix also calculates peratom
+   energies.
+
+The fix must also specify whether (by default) to include or exclude
+these contributions to the global/peratom energy/virial of the system.
+For the fix to include the contributions, set either of both of these
+variables in the constructor:
+
+* *thermo_energy* = 1, for global and peratom energy
+* *thermo_virial* = 1, for global and peratom virial
+
+Note that these variables are zeroed in fix.cpp.  Thus if you don't
+set the variables, the contributions will be excluded (by default)
+
+However, the user has ultimate control over whether to include or
+exclude the contributions of the fix via the :doc:`fix modify
+<fix_modify>` command:
+
+* fix modify *energy yes* to include global and peratom energy contributions
+* fix modify *virial yes* to include global and peratom virial contributions
+
+If the fix contributes to any of the global/peratom energy/virial
+values for the system, it should be explained on the fix doc page,
+along with the default values for the *energy yes/no* and *virial
+yes/no* settings of the :doc:`fix modify <fix_modify>` command.
+
+Finally, these 4 contributions are included in the output of 4
+computes:
+
+* global energy in :doc:`compute pe <compute_pe>`
+* peratom energy in :doc:`compute pe/atom <compute_pe_atom>`
+* global virial in :doc:`compute pressure <compute_pressure>`
+* peratom virial in :doc:`compute stress/atom <compute_stress_atom>`
+
+These computes invoke a method of the Modify class to include
+contributions from fixes that have the corresponding flags set,
+e.g. *energy_peratom_flag* and *thermo_energy* for :doc:`compute
+pe/atom <compute_pe_atom>`.
+
+Note that each compute has an optional keyword to either include or
+exclude all contributions from fixes.  Also note that :doc:`compute pe
+<compute_pe>` and :doc:`compute pressure <compute_pressure>` are what
+is used (by default) by :doc:`thermodynamic output <thermo_style>` to
+calculate values for its *pe* and *press* keywords.
+
+KSpace PPPM FFT grids
+^^^^^^^^^^^^^^^^^^^^^
+
+The various :doc:`KSpace PPPM <kspace_style>` styles in LAMMPS use
+FFTs to solve Poisson's equation.  This subsection describes:
+
+* how FFT grids are defined
+* how they are decomposed across processors
+* how they are indexed by each processor
+* how particle charge and electric field values are mapped to/from
+  the grid
+
+An FFT grid cell is a 3d volume; grid points are corners of a grid
+cell and the code stores values assigned to grid points in vectors or
+3d arrays.  A global 3d FFT grid has points indexed 0 to N-1 inclusive
+in each dimension.
+
+Each processor owns two subsets of the grid, each subset is
+brick-shaped.  Depending on how it is used, these subsets are
+allocated as a 1d vector or 3d array.  Either way, the ordering of
+values within contiguous memory x fastest, then y, z slowest.
+
+For the ``3d decomposition`` of the grid, the global grid is
+partitioned into bricks that correspond to the sub-domains of the
+simulation box that each processor owns.  Often, this is a regular 3d
+array (Px by Py by Pz) of bricks, where P = number of processors =
+Px * Py * Pz.  More generally it can be a tiled decomposition, where
+each processor owns a brick and the union of all the bricks is the
+global grid.  Tiled decompositions are produced by load balancing with
+the RCB algorithm; see the :doc:`balance rcb <balance>` command.
+
+For the ``FFT decompostion`` of the grid, each processor owns a brick
+that spans the entire x dimension of the grid while the y and z
+dimensions are partitioned as a regular 2d array (P1 by P2), where P =
+P1 * P2.
+
+The following indices store the inclusive bounds of the brick a
+processor owns, within the global grid:
+
+.. parsed-literal::
+
+   nxlo_in,nxhi_in,nylo_in,nyhi_in,nzlo_in,nzhi_in = 3d decomposition brick
+   nxlo_fft,nxhi_fft,nylo_fft,nyhi_fft,nzlo_fft,nzhi_fft = FFT decomposition brick
+   nxlo_out,nxhi_out,nylo_out,nyhi_out,nzlo_out,nzhi_out = 3d decomposition brick + ghost cells
+
+The ``in`` and ``fft`` indices are from 0 to N-1 inclusive in each
+dimension, where N is the grid size.
+
+The ``out`` indices index an array which stores the ``in`` subset of
+the grid plus ghost cells that surround it.  These indices can thus be
+< 0 or >= N.
+
+The number of ghost cells a processor owns in each of the 6 directions
+is a function of:
+
+.. parsed-literal::
+
+   neighbor skin distance (since atoms can move outside a proc subdomain)
+   qdist = offset or charge from atom due to TIP4P fictitious charge
+   order = mapping stencil size
+   shift = factor used when order is an even number (see below)
+
+Here is an explanation of how the PPPM variables ``order``,
+``nlower`` / ``nupper``, ``shift``, and ``OFFSET`` work. They are the
+relevant variables that determine how atom charge is mapped to grid
+points and how field values are mapped from grid points to atoms:
+
+.. parsed-literal::
+
+   order = # of nearby grid points in each dim that atom charge/field are mapped to/from
+   nlower,nupper = extent of stencil around the grid point an atom is assigned to
+   OFFSET = large integer added/subtracted when mapping to avoid int(-0.75) = 0 when -1 is the desired result
+
+The particle_map() method assigns each atom to a grid point.
+
+If order is even, say 4:
+
+.. parsed-literal::
+
+   atom is assigned to grid point to its left (in each dim)
+   shift = OFFSET
+   nlower = -1, nupper = 2, which are offsets from assigned grid point
+   window of mapping grid pts is thus 2 grid points to left of atom, 2 to right
+
+If order is odd, say 5:
+
+.. parsed-literal::
+
+   atom is assigned to left/right grid pt it is closest to (in each dim)
+   shift = OFFSET + 0.5
+   nlower = 2, nupper = 2
+   if point is in left half of cell, then window of affected grid pts is 3 grid points to left of atom, 2 to right
+   if point is in right half of cell, then window of affected grid pts is 2 grid points to left of atom, 3 to right
+
+These settings apply to each dimension, so that if order = 5, an
+atom's charge is mapped to 125 grid points that surround the atom.

doc/src/Developer_org.rst

@@ -1,68 +1,75 @@
 Source files
 ------------
 
-The source files of the LAMMPS code are found in two
+The source files of the LAMMPS code are found in two directories of the
-directories of the distribution: ``src`` and ``lib``.
+distribution: ``src`` and ``lib``.  Most of the code is written in C++
-Most of the code is C++ but there are small numbers of files
+but there are small a number of files in several other languages like C,
-in several other languages.
+Fortran, Shell script, or Python.
 
-The core of the code is located in the
+The core of the code is located in the ``src`` folder and its
-``src`` folder and its sub-directories.
+sub-directories.  A sizable number of these files are in the ``src``
-A sizable number of these files are in the ``src`` directory
+directory itself, but there are plenty of :doc:`packages <Packages>`,
-itself, but there are plenty of :doc:`packages <Packages>`, which can be
+which can be included or excluded when LAMMPS is built.  See the
-included or excluded when LAMMPS is built.  See the :doc:`Include
+:doc:`Include packages in build <Build_package>` section of the manual
-packages in build <Build_package>` section of the manual for more
+for more information about that part of the build process.  LAMMPS
-information about that part of the build process.  LAMMPS currently
+currently supports building with :doc:`conventional makefiles
-supports building with :doc:`conventional makefiles <Build_make>` and
+<Build_make>` and through :doc:`CMake <Build_cmake>`.  Those procedures
-through :doc:`CMake <Build_cmake>` which differ in how packages are
+differ in how packages are enabled or disabled for inclusion into a
-enabled or disabled for a LAMMPS binary.  The source files for each
+LAMMPS binary so they cannot be mixed.  The source files for each
 package are in all-uppercase sub-directories of the ``src`` folder, for
 example ``src/MOLECULE`` or ``src/USER-MISC``.  The ``src/STUBS``
 sub-directory is not a package but contains a dummy MPI library, that is
 used when building a serial version of the code. The ``src/MAKE``
-directory contains makefiles with settings and flags for a variety of
+directory and its sub-directories contain makefiles with settings and
-configuration and machines for the build process with traditional
+flags for a variety of configuration and machines for the build process
-makefiles.
+with traditional makefiles.
 
 The ``lib`` directory contains the source code for several supporting
 libraries or files with configuration settings to use globally installed
-libraries, that are required by some of the optional packages.
+libraries, that are required by some of the optional packages.  They may
-Each sub-directory, like ``lib/poems`` or ``lib/gpu``, contains the
+include python scripts that can transparently download additional source
-source files, some of which are in different languages such as Fortran
+code on request.  Each sub-directory, like ``lib/poems`` or ``lib/gpu``,
-or CUDA. These libraries are linked to during a LAMMPS build, if the
+contains the source files, some of which are in different languages such
-corresponding package is installed.
+as Fortran or CUDA. These libraries included in the LAMMPS build,
+if the corresponding package is installed.
 
 LAMMPS C++ source files almost always come in pairs, such as
 ``src/run.cpp`` (implementation file) and ``src/run.h`` (header file).
-Each pair of files defines a C++
+Each pair of files defines a C++ class, for example the
-class, for example the :cpp:class:`LAMMPS_NS::Run` class which contains
+:cpp:class:`LAMMPS_NS::Run` class which contains the code invoked by the
-the code invoked by the :doc:`run <run>` command in a LAMMPS input script.
+:doc:`run <run>` command in a LAMMPS input script.  As this example
-As this example illustrates, source file and class names often have a
+illustrates, source file and class names often have a one-to-one
-one-to-one correspondence with a command used in a LAMMPS input script.
+correspondence with a command used in a LAMMPS input script.  Some
-Some source files and classes do not have a corresponding input script
+source files and classes do not have a corresponding input script
 command, e.g. ``src/force.cpp`` and the :cpp:class:`LAMMPS_NS::Force`
 class.  They are discussed in the next section.
 
-A small number of C++ classes and utility functions are implemented with
+The names of all source files are in lower case and may use the
-only a ``.h`` file. Examples are the Pointer class or the MathVec functions.
+underscore character '_' to separate words. Outside of bundled libraries
+which may have different conventions, all C and C++ header files have a
+``.h`` extension, all C++ files have a ``.cpp`` extension, and C files a
+``.c`` extension. A small number of C++ classes and utility functions
+are implemented with only a ``.h`` file. Examples are the Pointers and
+Commands classes or the MathVec functions.
 
 Class topology
 --------------
 
 Though LAMMPS has a lot of source files and classes, its class topology
-is relative flat, as outlined in the :ref:`class-topology` figure.  Each
+is not very deep, which can be seen from the :ref:`class-topology`
-name refers to a class and has a pair of associated source files in the
+figure.  In that figure, each name refers to a class and has a pair of
-``src`` folder, for example the class :cpp:class:`LAMMPS_NS::Memory`
+associated source files in the ``src`` folder, for example the class
-corresponds to the files ``memory.cpp`` and ``memory.h``, or the class
+:cpp:class:`LAMMPS_NS::Memory` corresponds to the files ``memory.cpp``
-:cpp:class:`LAMMPS_NS::AtomVec` corresponds to the files
+and ``memory.h``, or the class :cpp:class:`LAMMPS_NS::AtomVec`
-``atom_vec.cpp`` and ``atom_vec.h``.  Full lines in the figure represent
+corresponds to the files ``atom_vec.cpp`` and ``atom_vec.h``.  Full
-compositing: that is the class to the left holds a pointer to an
+lines in the figure represent compositing: that is the class at the base
-instance of the class to the right.  Dashed lines instead represent
+of the arrow holds a pointer to an instance of the class at the tip.
-inheritance: the class to the right is derived from the class on the
+Dashed lines instead represent inheritance: the class to the tip of the
-left. Classes with a red boundary are not instantiated directly, but
+arrow is derived from the class at the base.  Classes with a red boundary
-they represent the base classes for "styles".  Those "styles" make up
+are not instantiated directly, but they represent the base classes for
-the bulk of the LAMMPS code and only a few typical examples are included
+"styles".  Those "styles" make up the bulk of the LAMMPS code and only
-in the figure for demonstration purposes.
+a few representative examples are included in the figure so it remains
+readable.
 
 .. _class-topology:
 .. figure:: JPG/lammps-classes.png
@@ -82,69 +89,76 @@ in the figure for demonstration purposes.
    derived classes, which may also hold instances of other classes.
 
 The :cpp:class:`LAMMPS_NS::LAMMPS` class is the topmost class and
-represents what is referred to an "instance" of LAMMPS.  It is a
+represents what is generally referred to an "instance" of LAMMPS.  It is
-composite holding references to instances of other core classes
+a composite holding pointers to instances of other core classes
 providing the core functionality of the MD engine in LAMMPS and through
 them abstractions of the required operations.  The constructor of the
 LAMMPS class will instantiate those instances, process the command line
 flags, initialize MPI (if not already done) and set up file pointers for
-input and output. The destructor will shut everything down and free all
+input and output.  The destructor will shut everything down and free all
 associated memory.  Thus code for the standalone LAMMPS executable in
 ``main.cpp`` simply initializes MPI, instantiates a single instance of
-LAMMPS, and passes it the command line flags and input script. It
+LAMMPS while passing it the command line flags and input script. It
 deletes the LAMMPS instance after the method reading the input returns
 and shuts down the MPI environment before it exits the executable.
 
 The :cpp:class:`LAMMPS_NS::Pointers` is not shown in the
-:ref:`class-topology` figure, it holds references to members of the
+:ref:`class-topology` figure for clarity.  It holds references to many
-`LAMMPS_NS::LAMMPS`, so that all classes derived from
+of the members of the `LAMMPS_NS::LAMMPS`, so that all classes derived
-:cpp:class:`LAMMPS_NS::Pointers` have direct access to those reference.
+from :cpp:class:`LAMMPS_NS::Pointers` have direct access to those
-From the class topology all classes with blue boundary are referenced in
+reference.  From the class topology all classes with blue boundary are
-this class and all classes in the second and third columns, that are not
+referenced in the Pointers class and all classes in the second and third
-listed as derived classes are instead derived from
+columns, that are not listed as derived classes are instead derived from
-:cpp:class:`LAMMPS_NS::Pointers`.
+:cpp:class:`LAMMPS_NS::Pointers`.  To initialize the pointer references
+in Pointers, a pointer to the LAMMPS class instance needs to be passed
+to the constructor and thus all constructors for classes derived from it
+must do so and pass this pointer to the constructor for Pointers.
 
-Since all storage is encapsulated, the LAMMPS class can also be
+Since all storage is supposed to be encapsulated (there are a few
-instantiated multiple times by a calling code, and that can be either
+exceptions), the LAMMPS class can also be instantiated multiple times by
-simultaneously or consecutively.  When running in parallel with MPI,
+a calling code.  Outside of the aforementioned exceptions, those LAMMPS
-care has to be taken, that suitable communicators are used to not
+instances can be used alternately.  As of the time of this writing
-create conflicts between different instances.
+(early 2021) LAMMPS is not yet sufficiently thread-safe for concurrent
+execution.  When running in parallel with MPI, care has to be taken,
+that suitable copies of communicators are used to not create conflicts
+between different instances.
 
-The LAMMPS class currently holds instances of 19 classes representing
+The LAMMPS class currently (early 2021) holds instances of 19 classes
-different core functionalities There are a handful of virtual parent
+representing the core functionality.  There are a handful of virtual
-classes in LAMMPS that define what LAMMPS calls ``styles``.  They are
+parent classes in LAMMPS that define what LAMMPS calls ``styles``.  They
-shaded red in the :ref:`class-topology` figure.  Each of these are
+are shaded red in the :ref:`class-topology` figure.  Each of these are
 parents of a number of child classes that implement the interface
 defined by the parent class.  There are two main categories of these
 ``styles``: some may only have one instance active at a time (e.g. atom,
 pair, bond, angle, dihedral, improper, kspace, comm) and there is a
-dedicated pointer variable in the composite class that manages them.
+dedicated pointer variable for each of them in the composite class.
 Setups that require a mix of different such styles have to use a
-*hybrid* class that manages and forwards calls to the corresponding
+*hybrid* class that takes the place of the one allowed instance and then
-sub-styles for the designated subset of atoms or data. or the composite
+manages and forwards calls to the corresponding sub-styles for the
-class may have lists of class instances, e.g. Modify handles lists of
+designated subset of atoms or data.  The composite class may also have
-compute and fix styles, while Output handles dumps class instances.
+lists of class instances, e.g. Modify handles lists of compute and fix
+styles, while Output handles a list of dump class instances.
 
-The exception to this scheme are the ``command`` style classes. These
+The exception to this scheme are the ``command`` style classes.  These
-implement specific commands that can be invoked before, after, or between
+implement specific commands that can be invoked before, after, or in
-runs or are commands which launch a simulation.  For these an instance
+between runs.  For these an instance of the class is created, its
-of the class is created, its command() method called and then, after
+command() method called and then, after completion, the class instance
-completion, the class instance deleted.  Examples for this are the
+deleted.  Examples for this are the create_box, create_atoms, minimize,
-create_box, create_atoms, minimize, run, or velocity command styles.
+run, set, or velocity command styles.
 
 For all those ``styles`` certain naming conventions are employed: for
-the fix nve command the class is called FixNVE and the files are
+the fix nve command the class is called FixNVE and the source files are
 ``fix_nve.h`` and ``fix_nve.cpp``. Similarly for fix ave/time we have
-FixAveTime and ``fix_ave_time.h`` and ``fix_ave_time.cpp``. Style names
+FixAveTime and ``fix_ave_time.h`` and ``fix_ave_time.cpp``.  Style names
 are lower case and without spaces or special characters. A suffix or
-multiple appended with a forward slash '/' denotes a variant of the
+words are appended with a forward slash '/' which denotes a variant of
-corresponding class without the suffix. To connect the style name and
+the corresponding class without the suffix.  To connect the style name
-the class name, LAMMPS uses macros like the following ATOM\_CLASS,
+and the class name, LAMMPS uses macros like: ``AtomStyle()``,
-PAIR\_CLASS, BOND\_CLASS, REGION\_CLASS, FIX\_CLASS, COMPUTE\_CLASS,
+``PairStyle()``, ``BondStyle()``, ``RegionStyle()``, and so on in the
-or DUMP\_CLASS in the corresponding header file.  During compilation
+corresponding header file.  During configuration or compilation files
-files with the pattern ``style_name.h`` are created that contain include
+with the pattern ``style_<name>.h`` are created that consist of a list
-statements including all headers of all styles of a given type that
+of include statements including all headers of all styles of a given
-are currently active (or "installed).
+type that are currently active (or "installed).
 
 
 More details on individual classes in the :ref:`class-topology` are as
@@ -152,20 +166,20 @@ follows:
 
 - The Memory class handles allocation of all large vectors and arrays.
 
-- The Error class prints all error and warning messages.
+- The Error class prints all (terminal) error and warning messages.
 
-- The Universe class sets up partitions of processors so that multiple
+- The Universe class sets up one or more partitions of processors so
-  simulations can be run, each on a subset of the processors allocated
+  that one or multiple simulations can be run, on the processors
-  for a run, e.g. by the mpirun command.
+  allocated for a run, e.g. by the mpirun command.
 
 - The Input class reads and processes input input strings and files,
   stores variables, and invokes :doc:`commands <Commands_all>`.
 
-- As discussed above, command style classes are directly derived from
+- Command style classes are derived from the Command class. They provide
-  the Pointers class. They provide input script commands that perform
+  input script commands that perform one-time operations
-  one-time operations before/after/between simulations or which invoke a
+  before/after/between simulations or which invoke a simulation.  They
-  simulation.  They are instantiated from within the Input class,
+  are usually instantiated from within the Input class, its ``command``
-  invoked, then immediately destructed.
+  method invoked, and then immediately destructed.
 
 - The Finish class is instantiated to print statistics to the screen
   after a simulation is performed, by commands like run and minimize.
@@ -241,7 +255,8 @@ follows:
 .. TODO section on "Spatial decomposition and parallel operations"
 ..       diagram of 3d processor grid, brick vs. tiled. local vs. ghost
 ..       atoms, 6-way communication with pack/unpack functions,
-..       PBC as part of the communication
+..       PBC as part of the communication, forward and reverse communication
+..       rendezvous communication, ring communication.
 
 .. TODO section on "Fixes, Computes, and Variables"
 ..      how and when data is computed and provided and how it is

doc/src/Developer_plugins.rst

@@ -0,0 +1,251 @@
+Writing plugins
+---------------
+
+Plugins provide a mechanism to add functionality to a LAMMPS executable
+without recompiling LAMMPS.  The functionality for this and the
+:doc:`plugin command <plugin>` are implemented in the
+:ref:`PLUGIN package <PKG-PLUGIN>` which must be installed to use plugins.
+
+Plugins use the operating system's capability to load dynamic shared
+object (DSO) files in a way similar shared libraries and then reference
+specific functions in those DSOs.  Any DSO file with plugins has to include
+an initialization function with a specific name, "lammpsplugin_init", that
+has to follow specific rules described below.  When loading the DSO with
+the "plugin" command, this function is looked up and called and will then
+register the contained plugin(s) with LAMMPS.
+
+From the programmer perspective this can work because of the object
+oriented design of LAMMPS where all pair style commands are derived from
+the class Pair, all fix style commands from the class Fix and so on and
+usually only functions present in those base classes are called
+directly.  When a :doc:`pair_style` command or :doc:`fix` command is
+issued a new instance of such a derived class is created.  This is done
+by a so-called factory function which is mapped to the style name.  Thus
+when, for example, the LAMMPS processes the command ``pair_style lj/cut
+2.5``, LAMMPS will look up the factory function for creating the
+``PairLJCut`` class and then execute it.  The return value of that
+function is a ``Pair *`` pointer and the pointer will be assigned to the
+location for the currently active pair style.
+
+A DSO file with a plugin thus has to implement such a factory function
+and register it with LAMMPS so that it gets added to the map of available
+styles of the given category.  To register a plugin with LAMMPS an
+initialization function has to be present in the DSO file called
+``lammpsplugin_init`` which is called with three ``void *`` arguments:
+a pointer to the current LAMMPS instance, a pointer to the opened DSO
+handle, and a pointer to the registration function.  The registration
+function takes two arguments: a pointer to a ``lammpsplugin_t`` struct
+with information about the plugin and a pointer to the current LAMMPS
+instance.  Please see below for an example of how the registration is
+done.
+
+Members of ``lammpsplugin_t``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. list-table::
+   :header-rows: 1
+   :widths: auto
+
+   * - Member
+     - Description
+   * - version
+     - LAMMPS Version string the plugin was compiled for
+   * - style
+     - Style of the plugin (pair, bond, fix, command, etc.)
+   * - name
+     - Name of the plugin style
+   * - info
+     - String with information about the plugin
+   * - author
+     - String with the name and email of the author
+   * - creator.v1
+     - Pointer to factory function for pair, bond, angle, dihedral, improper or command styles
+   * - creator.v2
+     - Pointer to factory function for compute, fix, or region styles
+   * - handle
+     - Pointer to the open DSO file handle
+
+Only one of the three alternate creator entries can be used at a time
+and which of those is determined by the style of plugin. The
+"creator.v1" element is for factory functions of supported styles
+computing forces (i.e.  command, pair, bond, angle, dihedral, or
+improper styles) and the function takes as single argument the pointer
+to the LAMMPS instance. The factory function is cast to the
+``lammpsplugin_factory1`` type before assignment.  The "creator.v2"
+element is for factory functions creating an instance of a fix, compute,
+or region style and takes three arguments: a pointer to the LAMMPS
+instance, an integer with the length of the argument list and a ``char
+**`` pointer to the list of arguments. The factory function pointer
+needs to be cast to the ``lammpsplugin_factory2`` type before
+assignment.
+
+Pair style example
+^^^^^^^^^^^^^^^^^^
+
+As an example, a hypothetical pair style plugin "morse2" implemented in
+a class ``PairMorse2`` in the files ``pair_morse2.h`` and
+``pair_morse2.cpp`` with the factory function and initialization
+function would look like this:
+
+.. code-block:: C++
+
+  #include "lammpsplugin.h"
+  #include "version.h"
+  #include "pair_morse2.h"
+
+  using namespace LAMMPS_NS;
+
+  static Pair *morse2creator(LAMMPS *lmp)
+  {
+    return new PairMorse2(lmp);
+  }
+
+  extern "C" void lammpsplugin_init(void *lmp, void *handle, void *regfunc)
+  {
+    lammpsplugin_regfunc register_plugin = (lammpsplugin_regfunc) regfunc;
+    lammpsplugin_t plugin;
+
+    plugin.version = LAMMPS_VERSION;
+    plugin.style   = "pair";
+    plugin.name    = "morse2";
+    plugin.info    = "Morse2 variant pair style v1.0";
+    plugin.author  = "Axel Kohlmeyer (akohlmey@gmail.com)";
+    plugin.creator.v1 = (lammpsplugin_factory1 *) &morse2creator;
+    plugin.handle  = handle;
+    (*register_plugin)(&plugin,lmp);
+  }
+
+The factory function in this example is called ``morse2creator()``.  It
+receives a pointer to the LAMMPS class as only argument and thus has to
+be assigned to the *creator.v1* member of the plugin struct and cast to
+the ``lammpsplugin_factory1`` function pointer type.  It returns a
+pointer to the allocated class instance derived from the ``Pair`` class.
+This function may be declared static to avoid clashes with other
+plugins.  The name of the derived class, ``PairMorse2``, however must be
+unique inside the entire LAMMPS executable.
+
+Fix style example
+^^^^^^^^^^^^^^^^^
+
+If the factory function would be for a fix or compute, which take three
+arguments (a pointer to the LAMMPS class, the number of arguments and the
+list of argument strings), then the pointer type is ``lammpsplugin_factory2``
+and it must be assigned to the *creator.v2* member of the plugin struct.
+Below is an example for that:
+
+.. code-block:: C++
+
+  #include "lammpsplugin.h"
+  #include "version.h"
+  #include "fix_nve2.h"
+
+  using namespace LAMMPS_NS;
+
+  static Fix *nve2creator(LAMMPS *lmp, int argc, char **argv)
+  {
+    return new FixNVE2(lmp,argc,argv);
+  }
+
+  extern "C" void lammpsplugin_init(void *lmp, void *handle, void *regfunc)
+  {
+    lammpsplugin_regfunc register_plugin = (lammpsplugin_regfunc) regfunc;
+    lammpsplugin_t plugin;
+
+    plugin.version = LAMMPS_VERSION;
+    plugin.style   = "fix";
+    plugin.name    = "nve2";
+    plugin.info    = "NVE2 variant fix style v1.0";
+    plugin.author  = "Axel Kohlmeyer (akohlmey@gmail.com)";
+    plugin.creator.v2 = (lammpsplugin_factory2 *) &nve2creator;
+    plugin.handle  = handle;
+    (*register_plugin)(&plugin,lmp);
+  }
+
+Command style example
+^^^^^^^^^^^^^^^^^^^^^
+Command styles also use the first variant of factory function as
+demonstrated in the following example, which also shows that the
+implementation of the plugin class may be within the same source
+file as the plugin interface code:
+
+.. code-block:: C++
+
+   #include "lammpsplugin.h"
+
+   #include "comm.h"
+   #include "error.h"
+   #include "command.h"
+   #include "version.h"
+
+   #include <cstring>
+
+   namespace LAMMPS_NS {
+     class Hello : public Command {
+      public:
+       Hello(class LAMMPS *lmp) : Command(lmp) {};
+       void command(int, char **);
+     };
+   }
+
+   using namespace LAMMPS_NS;
+
+   void Hello::command(int argc, char **argv)
+   {
+      if (argc != 1) error->all(FLERR,"Illegal hello command");
+      if (comm->me == 0)
+        utils::logmesg(lmp,fmt::format("Hello, {}!\n",argv[0]));
+   }
+
+   static void hellocreator(LAMMPS *lmp)
+   {
+     return new Hello(lmp);
+   }
+
+   extern "C" void lammpsplugin_init(void *lmp, void *handle, void *regfunc)
+   {
+     lammpsplugin_t plugin;
+     lammpsplugin_regfunc register_plugin = (lammpsplugin_regfunc) regfunc;
+
+     plugin.version = LAMMPS_VERSION;
+     plugin.style   = "command";
+     plugin.name    = "hello";
+     plugin.info    = "Hello world command v1.1";
+     plugin.author  = "Axel Kohlmeyer (akohlmey@gmail.com)";
+     plugin.creator.v1 = (lammpsplugin_factory1 *) &hellocreator;
+     plugin.handle  = handle;
+     (*register_plugin)(&plugin,lmp);
+   }
+
+Additional Details
+^^^^^^^^^^^^^^^^^^
+
+The initialization function **must** be called ``lammpsplugin_init``, it
+**must** have C bindings and it takes three void pointers as arguments.
+The first is a pointer to the LAMMPS class that calls it and it needs to
+be passed to the registration function.  The second argument is a
+pointer to the internal handle of the DSO file, this needs to be added
+to the plugin info struct, so that the DSO can be closed and unloaded
+when all its contained plugins are unloaded.  The third argument is a
+function pointer to the registration function and needs to be stored
+in a variable of ``lammpsplugin_regfunc`` type and then called with a
+pointer to the ``lammpsplugin_t`` struct and the pointer to the LAMMPS
+instance as arguments to register a single plugin.  There may be multiple
+calls to multiple plugins in the same initialization function.
+
+To register a plugin a struct of the ``lammpsplugin_t`` needs to be filled
+with relevant info: current LAMMPS version string, kind of style, name of
+style, info string, author string, pointer to factory function, and the
+DSO handle.  The registration function is called with a pointer to the address
+of this struct and the pointer of the LAMMPS class.  The registration function
+will then add the factory function of the plugin style to the respective
+style map under the provided name.  It will also make a copy of the struct
+in a list of all loaded plugins and update the reference counter for loaded
+plugins from this specific DSO file.
+
+The pair style itself (i.e. the PairMorse2 class in this example) can be
+written just like any other pair style that is included in LAMMPS.  For
+a plugin, the use of the ``PairStyle`` macro in the section encapsulated
+by ``#ifdef PAIR_CLASS`` is not needed, since the mapping of the class
+name to the style name is done by the plugin registration function with
+the information from the ``lammpsplugin_t`` struct.  It may be included
+in case the new code is intended to be later included in LAMMPS directly.

doc/src/Developer_unittest.rst

@@ -0,0 +1,536 @@
+Adding tests for unit testing
+-----------------------------
+
+This section discusses adding or expanding tests for the unit test
+infrastructure included into the LAMMPS source code distribution.
+Unlike example inputs, unit tests focus on testing the "local" behavior
+of individual features, tend to run fast, and should be set up to cover
+as much of the added code as possible.  When contributing code to the
+distribution, the LAMMPS developers will appreciate if additions to the
+integrated unit test facility are included.
+
+Given the complex nature of MD simulations where many operations can
+only be performed when suitable "real" simulation environment has been
+set up, not all tests will be unit tests in the strict definition of
+the term.  They are rather executed on a more abstract level by issuing
+LAMMPS script commands and then inspecting the changes to the internal
+data.  For some classes of tests, generic test programs have been
+written that can be applied to parts of LAMMPS that use the same
+interface (via polymorphism) and those are driven by input files, so
+tests can be added by simply adding more of those input files.  Those
+tests should be seen more as a hybrid between unit and regression tests.
+
+When adding tests it is recommended to also :ref:`enable support for
+code coverage reporting <testing>`, and study the coverage reports
+so that it is possible to monitor which parts of the code of a given
+file are executed during the tests and which tests would need to be
+added to increase the coverage.
+
+The tests are grouped into categories and corresponding folders.
+The following sections describe how the tests are implemented and
+executed in those categories with increasing complexity of tests
+and implementation.
+
+
+Tests for utility functions
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+These tests are driven by programs in the ``unittest/utils`` folder
+and most closely resemble conventional unit tests. There is one test
+program for each namespace or group of classes or file. The naming
+convention for the sources and executables is that they start with
+with ``test_``.  The following sources and groups of tests are currently
+available:
+
+.. list-table::
+   :header-rows: 1
+   :widths: auto
+   :align: left
+
+   * - File name:
+     - Test name:
+     - Description:
+   * - ``test_argutils.cpp``
+     - ArgInfo
+     - Tests for ``ArgInfo`` class used by LAMMPS
+   * - ``test_fmtlib.cpp``
+     - FmtLib
+     - Tests for ``fmtlib::`` functions used by LAMMPS
+   * - ``test_math_eigen_impl.cpp``
+     - MathEigen
+     - Tests for ``MathEigen::`` classes and functions
+   * - ``test_mempool.cpp``
+     - MemPool
+     - Tests for :cpp:class:`MyPage <LAMMPS_NS::MyPage>` and :cpp:class:`MyPoolChunk <LAMMPS_NS::MyPoolChunk>`
+   * - ``test_tokenizer.cpp``
+     - Tokenizer
+     - Tests for :cpp:class:`Tokenizer <LAMMPS_NS::Tokenizer>` and :cpp:class:`ValueTokenizer <LAMMPS_NS::ValueTokenizer>`
+   * - ``test_utils.cpp``
+     - Utils
+     - Tests for ``utils::`` :doc:`functions <Developer_utils>`
+
+To add tests either an existing source file needs to be modified or a
+new source file needs to be added to the distribution and enabled for
+testing.  To add a new file suitable CMake script code needs to be added
+to the ``CMakeLists.txt`` file in the ``unittest/utils`` folder.  Example:
+
+.. code-block:: cmake
+
+   add_executable(test_tokenizer test_tokenizer.cpp)
+   target_link_libraries(test_tokenizer PRIVATE lammps GTest::GMockMain GTest::GMock GTest::GTest)
+   add_test(Tokenizer test_tokenizer)
+
+This adds instructions to build the ``test_tokenizer`` executable from
+``test_tokenizer.cpp`` and links it with the GoogleTest libraries and the
+LAMMPS library as well as it uses the ``main()`` function from the
+GoogleMock library of GoogleTest.  The third line registers the executable
+as a test program to be run from ``ctest`` under the name ``Tokenizer``.
+
+The test executable itself will execute multiple individual tests
+through the GoogleTest framework. In this case each test consists of
+creating a tokenizer class instance with a given string and explicit or
+default separator choice, and then executing member functions of the
+class and comparing their results with expected values. A few examples:
+
+.. code-block:: c++
+
+   TEST(Tokenizer, empty_string)
+   {
+       Tokenizer t("", " ");
+       ASSERT_EQ(t.count(), 0);
+   }
+
+   TEST(Tokenizer, two_words)
+   {
+       Tokenizer t("test word", " ");
+       ASSERT_EQ(t.count(), 2);
+   }
+
+   TEST(Tokenizer, default_separators)
+   {
+       Tokenizer t(" \r\n test \t word \f");
+       ASSERT_THAT(t.next(), Eq("test"));
+       ASSERT_THAT(t.next(), Eq("word"));
+       ASSERT_EQ(t.count(), 2);
+   }
+
+Each of these TEST functions will become an individual
+test run by the test program. When using the ``ctest``
+command as a front end to run the tests, their output
+will be suppressed and only a summary printed, but adding
+the '-V' option will then produce output from the tests
+above like the following:
+
+.. code-block::
+
+   [...]
+   1: [ RUN      ] Tokenizer.empty_string
+   1: [       OK ] Tokenizer.empty_string (0 ms)
+   1: [ RUN      ] Tokenizer.two_words
+   1: [       OK ] Tokenizer.two_words (0 ms)
+   1: [ RUN      ] Tokenizer.default_separators
+   1: [       OK ] Tokenizer.default_separators (0 ms)
+   [...]
+
+The MathEigen test collection has been adapted from a standalone test
+and does not use the GoogleTest framework and thus not representative.
+The other test sources, however, can serve as guiding examples for
+additional tests.
+
+Tests for individual LAMMPS commands
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The tests ``unittest/commands`` are a bit more complex as they require
+to first create a :cpp:class:`LAMMPS <LAMMPS_NS::LAMMPS>` class instance
+and then use the :doc:`C++ API <Cplusplus>` to pass individual commands
+to that LAMMPS instance.  For that reason these tests use a GoogleTest
+"test fixture", i.e. a class derived from ``testing::Test`` that will
+create (and delete) the required LAMMPS class instance for each set of
+tests in a ``TEST_F()`` function.  Please see the individual source files
+for different examples of setting up suitable test fixtures.  Here is an
+example for implementing a test using a fixture by first checking the
+default value and then issuing LAMMPS commands and checking whether they
+have the desired effect:
+
+.. code-block:: c++
+
+   TEST_F(SimpleCommandsTest, ResetTimestep)
+   {
+       ASSERT_EQ(lmp->update->ntimestep, 0);
+
+       BEGIN_HIDE_OUTPUT();
+       command("reset_timestep 10");
+       END_HIDE_OUTPUT();
+       ASSERT_EQ(lmp->update->ntimestep, 10);
+
+       BEGIN_HIDE_OUTPUT();
+       command("reset_timestep 0");
+       END_HIDE_OUTPUT();
+       ASSERT_EQ(lmp->update->ntimestep, 0);
+
+       TEST_FAILURE(".*ERROR: Timestep must be >= 0.*", command("reset_timestep -10"););
+       TEST_FAILURE(".*ERROR: Illegal reset_timestep .*", command("reset_timestep"););
+       TEST_FAILURE(".*ERROR: Illegal reset_timestep .*", command("reset_timestep 10 10"););
+       TEST_FAILURE(".*ERROR: Expected integer .*", command("reset_timestep xxx"););
+   }
+
+Please note the use of the ``BEGIN_HIDE_OUTPUT`` and ``END_HIDE_OUTPUT``
+functions that will capture output from running LAMMPS.  This is normally
+discarded but by setting the verbose flag (via setting the ``TEST_ARGS``
+environment variable, ``TEST_ARGS=-v``) it can be printed and used to
+understand why tests fail unexpectedly.
+
+Another complexity of these tests stems from the need to capture
+situations where LAMMPS will stop with an error, i.e. handle so-called
+"death tests".  Here the LAMMPS code will operate differently depending
+on whether it was configured to throw C++ exceptions on errors or call
+either ``exit()`` or ``MPI_Abort()``.  In the latter case, the test code
+also needs to detect whether LAMMPS was compiled with the OpenMPI
+library, as OpenMPI is **only** compatible the death test options of the
+GoogleTest library when C++ exceptions are enabled; otherwise those
+"death tests" must be skipped to avoid reporting bogus failures.  The
+specifics of this step are implemented in the ``TEST_FAILURE()``
+macro. These tests operate by capturing the screen output when executing
+the failing command and then comparing that with a provided regular
+expression string pattern.  Example:
+
+.. code-block:: C++
+
+   TEST_F(SimpleCommandsTest, UnknownCommand)
+   {
+       TEST_FAILURE(".*ERROR: Unknown command.*", lmp->input->one("XXX one two"););
+   }
+
+The following test programs are currently available:
+
+.. list-table::
+   :header-rows: 1
+   :widths: auto
+   :align: left
+
+   * - File name:
+     - Test name:
+     - Description:
+   * - ``test_simple_commands.cpp``
+     - SimpleCommands
+     - Tests for LAMMPS commands that do not require a box
+   * - ``test_lattice_region.cpp``
+     - LatticeRegion
+     - Tests to validate the :doc:`lattice <lattice>` and :doc:`region <region>` commands
+   * - ``test_groups.cpp``
+     - GroupTest
+     - Tests to validate the :doc:`group <group>` command
+   * - ``test_variables.cpp``
+     - VariableTest
+     - Tests to validate the :doc:`variable <variable>` command
+   * - ``test_kim_commands.cpp``
+     - KimCommands
+     - Tests for several commands from the :ref:`KIM package <PKG-KIM>`
+   * - ``test_reset_ids.cpp``
+     - ResetIDs
+     - Tests to validate the :doc:`reset_atom_ids <reset_atom_ids>` and :doc:`reset_mol_ids <reset_mol_ids>` commands
+
+
+Tests for the C-style library interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Tests for validating the LAMMPS C-style library interface are in the
+``unittest/c-library`` folder.  They are implemented in either way used
+for utility functions and for LAMMPS commands, but use the functions
+implemented in the ``src/library.cpp`` file as much as possible.  There
+may be some overlap with other tests, but only in as much as is required
+to test the C-style library API.  The tests are distributed over
+multiple test programs which tries to match the grouping of the
+functions in the source code and :ref:`in the manual <lammps_c_api>`.
+
+This group of tests also includes tests invoking LAMMPS in parallel
+through the library interface, provided that LAMMPS was compiled with
+MPI support.  These include tests where LAMMPS is run in multi-partition
+mode or only on a subset of the MPI world communicator.  The CMake
+script code for adding this kind of test looks like this:
+
+.. code-block:: CMake
+
+   if (BUILD_MPI)
+     add_executable(test_library_mpi test_library_mpi.cpp)
+     target_link_libraries(test_library_mpi PRIVATE lammps GTest::GTest GTest::GMock)
+     target_compile_definitions(test_library_mpi PRIVATE ${TEST_CONFIG_DEFS})
+     add_mpi_test(NAME LibraryMPI NUM_PROCS 4 COMMAND $<TARGET_FILE:test_library_mpi>)
+   endif()
+
+Note the custom function ``add_mpi_test()`` which adapts how ``ctest``
+will execute the test so it is launched in parallel (with 4 MPI ranks).
+
+Tests for the Python module and package
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``unittest/python`` folder contains primarily tests for classes and
+functions in the LAMMPS python module but also for commands in the
+PYTHON package.  These tests are only enabled, if the necessary
+prerequisites are detected or enabled during configuration and
+compilation of LAMMPS (shared library build enabled, Python interpreter
+found, Python development files found).
+
+The Python tests are implemented using the ``unittest`` standard Python
+module and split into multiple files with similar categories as the
+tests for the C-style library interface.
+
+Tests for the Fortran interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Tests for using the Fortran module are in the ``unittest/fortran``
+folder.  Since they are also using the GoogleTest library, they require
+to also implement test wrappers in C++ that will call fortran functions
+which provide a C function interface through ISO_C_BINDINGS that will in
+turn call the functions in the LAMMPS Fortran module.  This part of the
+unit tests is incomplete since the Fortran module it is based on is
+incomplete as well.
+
+Tests for the C++-style library interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The tests in the ``unittest/cplusplus`` folder are somewhat similar to
+the tests for the C-style library interface, but do not need to test the
+several convenience and utility functions that are only available through
+the C-style interface.  Instead it can focus on the more generic features
+that are used internally.  This part of the unit tests is currently still
+mostly in the planning stage.
+
+Tests for reading and writing file formats
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``unittest/formats`` folder contains test programs for reading and
+writing files like data files, restart files, potential files or dump files.
+This covers simple things like the file i/o convenience functions in the
+``utils::`` namespace to complex tests of atom styles where creating and
+deleting of atoms with different properties is tested in different ways
+and through script commands or reading and writing of data or restart files.
+
+Tests for styles computing or modifying forces
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+These are tests common configurations for pair styles, bond styles,
+angle styles, kspace styles and certain fix styles.  Those are tests
+driven by some test executables build from sources in the
+``unittest/force-styles`` folder and use LAMMPS input template and data
+files as well as input files in YAML format from the
+``unittest/force-styles/tests`` folder. The YAML file names have to
+follow some naming conventions so they get associated with the test
+programs and categorized and listed with canonical names in the list
+of tests as displayed by ``ctest -N``.  If you add a new YAML file,
+you need to re-run CMake to update the corresponding list of tests.
+
+A minimal YAML file for a (molecular) pair style test will looks
+something like the following (see ``mol-pair-zero.yaml``):
+
+.. code-block:: yaml
+
+   ---
+   lammps_version: 24 Aug 2020
+   date_generated: Tue Sep 15 09:44:21 202
+   epsilon: 1e-14
+   prerequisites: ! |
+     atom full
+     pair zero
+   pre_commands: ! ""
+   post_commands: ! ""
+   input_file: in.fourmol
+   pair_style: zero 8.0
+   pair_coeff: ! |
+     * *
+   extract: ! ""
+   natoms: 29
+   init_vdwl: 0
+   init_coul: 0
+
+   [...]
+
+The following table describes the available keys and their purpose for
+testing pair styles:
+
+.. list-table::
+   :header-rows: 1
+
+   * - Key:
+     - Description:
+   * - lammps_version
+     - LAMMPS version used to last update the reference data
+   * - date_generated
+     - date when the file was last updated
+   * - epsilon
+     - base value for the relative precision required for tests to pass
+   * - prerequisites
+     - list of style kind / style name pairs required to run the test
+   * - pre_commands
+     - LAMMPS commands to be executed before the input template file is read
+   * - post_commands
+     - LAMMPS commands to be executed right before the actual tests
+   * - input_file
+     - LAMMPS input file template based on pair style zero
+   * - pair_style
+     - arguments to the pair_style command to be tested
+   * - pair_coeff
+     - list of pair_coeff arguments to set parameters for the input template
+   * - extract
+     - list of keywords supported by ``Pair::extract()`` and their dimension
+   * - natoms
+     - number of atoms in the input file template
+   * - init_vdwl
+     - non-Coulomb pair energy after "run 0"
+   * - init_coul
+     - Coulomb pair energy after "run 0"
+   * - init_stress
+     - stress tensor after "run 0"
+   * - init_forces
+     - forces on atoms after "run 0"
+   * - run_vdwl
+     - non-Coulomb pair energy after "run 4"
+   * - run_coul
+     - Coulomb pair energy after "run 4"
+   * - run_stress
+     - stress tensor after "run 4"
+   * - run_forces
+     - forces on atoms after "run 4"
+
+The test program will read all this data from the YAML file and then
+create a LAMMPS instance, apply the settings/commands from the YAML file
+as needed and then issue a "run 0" command, write out a restart file, a
+data file and a coeff file. The actual test will then compare computed
+energies, stresses, and forces with the reference data, issue a "run 4"
+command and compare to the second set of reference data.  This will be
+run with both the newton_pair setting enabled and disabled and is
+expected to generate the same results (allowing for some numerical
+noise). Then it will restart from the previously generated restart and
+compare with the reference and also start from the data file.  A final
+check will use multi-cutoff r-RESPA (if supported by the pair style) at
+a 1:1 split and compare to the Verlet results.  These sets of tests are
+run with multiple test fixtures for accelerated styles (OPT, USER-OMP,
+USER-INTEL) and for the latter two with 4 OpenMP threads enabled.  For
+these tests the relative error (epsilon) is lowered by a common factor
+due to the additional numerical noise, but the tests are still comparing
+to the same reference data.
+
+Additional tests will check whether all listed extract keywords are
+supported and have the correct dimensionality and the final set of tests
+will set up a few pairs of atoms explicitly and in such a fashion that
+the forces on the atoms computed from ``Pair::compute()`` will match
+individually with the results from ``Pair::single()``, if the pair style
+does support that functionality.
+
+With this scheme a large fraction of the code of any tested pair style
+will be executed and consistent results are required for different
+settings and between different accelerated pair style variants and the
+base class, as well as for computing individual pairs through the
+``Pair::single()`` where supported.
+
+The ``test_pair_style`` tester is used with 4 categories of test inputs:
+
+- pair styles compatible with molecular systems using bonded
+  interactions and exclusions.  For pair styles requiring a KSpace style
+  the KSpace computations are disabled.  The YAML files match the
+  pattern "mol-pair-\*.yaml" and the tests are correspondingly labeled
+  with "MolPairStyle:\*"
+- pair styles not compatible with the previous input template.
+  The YAML files match the pattern "atomic-pair-\*.yaml" and the tests are
+  correspondingly labeled with "AtomicPairStyle:\*"
+- manybody pair styles.
+  The YAML files match the pattern "atomic-pair-\*.yaml" and the tests are
+  correspondingly labeled with "AtomicPairStyle:\*"
+- kspace styles.
+  The YAML files match the pattern "kspace-\*.yaml" and the tests are
+  correspondingly labeled with "KSpaceStyle:\*". In these cases a compatible
+  pair style is defined, but the computation of the pair style contributions
+  is disabled.
+
+The ``test_bond_style`` and ``test_angle_style`` are set up in a similar
+fashion and share support functions with the pair style tester.  The final
+group of tests in this section is for fix styles that add/manipulate forces
+and velocities, e.g. for time integration, thermostats and more.
+
+Adding a new test is easiest done by copying and modifying an existing test
+for a style that is similar to one to be tested.  The file name should follow
+the naming conventions described above and after copying the file, the first
+step is to replace the style names where needed.  The coefficient values
+do not have to be meaningful, just in a reasonable range for the given system.
+It does not matter if some forces are large, for as long as they do not diverge.
+
+The template input files define a large number of index variables at the top
+that can be modified inside the YAML file to control the behavior.  For example,
+if a pair style requires a "newton on" setting, the following can be used in
+as the "pre_commands" section:
+
+.. code-block:: yaml
+
+   pre_commands: ! |
+     variable newton_pair delete
+     variable newton_pair index on
+
+And for a pair style requiring a kspace solver the following would be used as
+the "post_commands" section:
+
+.. code-block:: yaml
+
+   post_commands: ! |
+     pair_modify table 0
+     kspace_style pppm/tip4p 1.0e-6
+     kspace_modify gewald 0.3
+     kspace_modify compute no
+
+Note that this disables computing the kspace contribution, but still will run
+the setup.  The "gewald" parameter should be set explicitly to speed up the run.
+For styles with long-range electrostatics, typically two tests are added one using
+the (slower) analytic approximation of the erfc() function and the other using
+the tabulated coulomb, to test both code paths. The reference results in the YAML
+files then should be compared manually, if they agree well enough within the limits
+of those two approximations.
+
+The ``test_pair_style`` and equivalent programs have special command line options
+to update the YAML files. Running a command like
+
+.. code-block:: bash
+
+   $ test_pair_style mol-pair-lennard_mdf.yaml -g new.yaml
+
+will read the settings from the ``mol-pair-lennard_mdf.yaml`` file and then compute
+the reference data and write a new file with to ``new.yaml``.  If this step fails,
+there are likely some (LAMMPS or YAML) syntax issues in the YAML file that need to
+be resolved and then one can compare the two files to see if the output is as expected.
+
+It is also possible to do an update in place with:
+
+.. code-block:: bash
+
+   $ test_pair_style mol-pair-lennard_mdf.yaml -u
+
+And one can finally run the full set of tests with:
+
+.. code-block:: bash
+
+   $ test_pair_style mol-pair-lennard_mdf.yaml
+
+This will just print a summary of the groups of tests.  When using the "-v" flag
+the test will also keep any LAMMPS output and when using the "-s" flag, there
+will be some statistics reported on the relative errors for the individual checks
+which can help to figure out what would be a good choice of the epsilon parameter.
+It should be as small as possible to catch any unintended side effects from changes
+elsewhere, but large enough to accommodate the numerical noise due to the implementation
+of the potentials and differences in compilers.
+
+.. note::
+
+   These kinds of tests can be very sensitive to compiler optimization and
+   thus the expectation is that they pass with compiler optimization turned
+   off. When compiler optimization is enabled, there may be some failures, but
+   one has to carefully check whether those are acceptable due to the enhanced
+   numerical noise from reordering floating-point math operations or due to
+   the compiler mis-compiling the code. That is not always obvious.
+
+
+Tests for programs in the tools folder
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``unittest/tools`` folder contains tests for programs in the
+``tools`` folder.  This currently only contains tests for the LAMMPS
+shell, which are implemented as a python scripts using the ``unittest``
+Python module and launching the tool commands through the ``subprocess``
+Python module.

doc/src/Developer_utils.rst

@@ -9,14 +9,29 @@ reading or writing to files with error checking or translation of
 strings into specific types of numbers with checking for validity.  This
 reduces redundant implementations and encourages consistent behavior.
 
-I/O with status check
+I/O with status check and similar functions
-^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-These are wrappers around the corresponding C library calls like
+The the first two functions are wrappers around the corresponding C
-``fgets()`` or ``fread()``.  They will check if there were errors
+library calls ``fgets()`` or ``fread()``.  They will check if there
-on reading or an unexpected end-of-file state was reached.  In that
+were errors on reading or an unexpected end-of-file state was reached.
-case, the functions will stop the calculation with an error message,
+In that case, the functions will stop with an error message, indicating
-indicating the name of the problematic file, if possible.
+the name of the problematic file, if possible unless the *error* argument
+is a NULL pointer.
+
+The :cpp:func:`fgets_trunc` function will work similar for ``fgets()``
+but it will read in a whole line (i.e. until the end of line or end
+of file), but store only as many characters as will fit into the buffer
+including a final newline character and the terminating NULL byte.
+If the line in the file is longer it will thus be truncated in the buffer.
+This function is used by :cpp:func:`read_lines_from_file` to read individual
+lines but make certain they follow the size constraints.
+
+The :cpp:func:`read_lines_from_file` function will read the requested
+number of lines of a maximum length into a buffer and will return 0
+if successful or 1 if not. It also guarantees that all lines are
+terminated with a newline character and the entire buffer with a
+NULL character.
 
 ----------
 
@@ -26,6 +41,12 @@ indicating the name of the problematic file, if possible.
 .. doxygenfunction:: sfread
    :project: progguide
 
+.. doxygenfunction:: fgets_trunc
+   :project: progguide
+
+.. doxygenfunction:: read_lines_from_file
+   :project: progguide
+
 ----------
 
 String to number conversions with validity check
@@ -71,12 +92,21 @@ and parsing files or arguments.
 
 ----------
 
+.. doxygenfunction:: strdup
+   :project: progguide
+
 .. doxygenfunction:: trim
    :project: progguide
 
 .. doxygenfunction:: trim_comment
    :project: progguide
 
+.. doxygenfunction:: has_utf8
+   :project: progguide
+
+.. doxygenfunction:: utf8_subst
+   :project: progguide
+
 .. doxygenfunction:: count_words(const char *text)
    :project: progguide
 
@@ -92,9 +122,15 @@ and parsing files or arguments.
 .. doxygenfunction:: split_words
    :project: progguide
 
+.. doxygenfunction:: split_lines
+   :project: progguide
+
 .. doxygenfunction:: strmatch
    :project: progguide
 
+.. doxygenfunction:: strfind
+   :project: progguide
+
 .. doxygenfunction:: is_integer
    :project: progguide
 
@@ -149,7 +185,10 @@ Argument processing
 Convenience functions
 ^^^^^^^^^^^^^^^^^^^^^
 
-.. doxygenfunction:: logmesg
+.. doxygenfunction:: logmesg(LAMMPS *lmp, const S &format, Args&&... args)
+   :project: progguide
+
+.. doxygenfunction:: logmesg(LAMMPS *lmp, const std::string &mesg)
    :project: progguide
 
 .. doxygenfunction:: getsyserror
@@ -286,6 +325,50 @@ This code example should produce the following output:
 
 ----------
 
+
+Argument parsing classes
+---------------------------
+
+The purpose of argument parsing classes it to simplify and unify how
+arguments of commands in LAMMPS are parsed and to make abstractions of
+repetitive tasks.
+
+The :cpp:class:`LAMMPS_NS::ArgInfo` class provides an abstraction
+for parsing references to compute or fix styles or variables. These
+would start with a "c\_", "f\_", "v\_" followed by the ID or name of
+than instance and may be postfixed with one or two array indices
+"[<number>]" with numbers > 0.
+
+A typical code segment would look like this:
+
+.. code-block:: C++
+   :caption: Usage example for ArgInfo class
+
+   int nvalues = 0;
+   for (iarg = 0; iarg < nargnew; iarg++) {
+     ArgInfo argi(arg[iarg]);
+
+     which[nvalues] = argi.get_type();
+     argindex[nvalues] = argi.get_index1();
+     ids[nvalues] = argi.copy_name();
+
+     if ((which[nvalues] == ArgInfo::UNKNOWN)
+          || (which[nvalues] == ArgInfo::NONE)
+          || (argi.get_dim() > 1))
+       error->all(FLERR,"Illegal compute XXX command");
+
+     nvalues++;
+   }
+
+----------
+
+.. doxygenclass:: LAMMPS_NS::ArgInfo
+   :project: progguide
+   :members:
+
+
+----------
+
 File reader classes
 -------------------
 

doc/src/Developer_write.rst

@@ -59,7 +59,7 @@ of each timestep. First of all, implement a constructor:
    }
 
 In the constructor you should parse your fix arguments which are
-specified in the script. All fixes have pretty the same syntax:
+specified in the script. All fixes have pretty much the same syntax:
 ``fix <fix-ID> <fix group> <fix name> <fix arguments ...>``. The
 first 3 parameters are parsed by Fix base class constructor, while
 ``<fix arguments>`` should be parsed by you. In our case, we need to

doc/src/Errors_bugs.rst

@@ -5,8 +5,8 @@ If you are confident that you have found a bug in LAMMPS, please follow
 the steps outlined below:
 
  * Check the `New features and bug fixes
-   <https://lammps.sandia.gov/bug.html>`_ section of the `LAMMPS WWW site
+   <https://www.lammps.org/bug.html>`_ section of the `LAMMPS WWW site
-   <https://lammps.sandia.gov>`_ or the
+   <https://www.lammps.org>`_ or the
    `GitHub Releases page <https://github.com/lammps/lammps/releases>`_ to
    see if the bug has already been addressed in a patch release.
  * Check that your issue can be reproduced with the latest development
@@ -17,7 +17,7 @@ the steps outlined below:
    if your issue has already been reported and if it is still open.
  * Check the `GitHub Pull Requests page <https://github.com/lammps/lammps/pulls>`_
    to see if there is already a fix for your bug pending.
- * Check the `mailing list archives <https://lammps.sandia.gov/mail.html>`_
+ * Check the `mailing list archives <https://www.lammps.org/mail.html>`_
    to see if the issue has been discussed before.
 
 If none of these steps yields any useful information, please file a new

doc/src/Errors_common.rst

@@ -39,7 +39,7 @@ figure out your physics or numerical mistakes, like choosing too big a
 timestep, specifying erroneous force field coefficients, or putting 2
 atoms on top of each other!  If you run into errors that LAMMPS
 does not catch that you think it should flag, please send an email to
-the `developers <https://lammps.sandia.gov/authors.html>`_.
+the `developers <https://www.lammps.org/authors.html>`_.
 
 If you get an error message about an invalid command in your input
 script, you can determine what command is causing the problem by

doc/src/Errors_messages.rst

@@ -3871,7 +3871,7 @@ Doc page with :doc:`WARNING messages <Errors_warnings>`
 *Fix orient/fcc found self twice*
    The neighbor lists used by fix orient/fcc are messed up.  If this
    error occurs, it is likely a bug, so send an email to the
-   `developers <https://lammps.sandia.gov/authors.html>`_.
+   `developers <https://www.lammps.org/authors.html>`_.
 
 *Fix peri neigh does not exist*
    Somehow a fix that the pair style defines has been deleted.

doc/src/Errors_warnings.rst

@@ -119,7 +119,6 @@ Doc page with :doc:`ERROR messages <Errors_messages>`
    :doc:`pair style zero <pair_zero>` with a suitable cutoff or use :doc:`comm_modify cutoff <comm_modify>`.
 
 *Communication cutoff is shorter than a bond length based estimate. This may lead to errors.*
-
    Since LAMMPS stores topology data with individual atoms, all atoms
    comprising a bond, angle, dihedral or improper must be present on any
    sub-domain that "owns" the atom with the information, either as a

doc/src/Examples.rst

@@ -18,7 +18,7 @@ files and image files.
 
 If you uncomment the :doc:`dump <dump>` command in the input script, a
 text dump file will be produced, which can be animated by various
-`visualization programs <https://lammps.sandia.gov/viz.html>`_.
+`visualization programs <https://www.lammps.org/viz.html>`_.
 
 If you uncomment the :doc:`dump image <dump>` command in the input
 script, and assuming you have built LAMMPS with a JPG library, JPG
@@ -27,7 +27,7 @@ be quickly post-processed into a movie using commands described on the
 :doc:`dump image <dump_image>` doc page.
 
 Animations of many of the examples can be viewed on the Movies section
-of the `LAMMPS web site <https://lammps.sandia.gov/movies.html>`_.
+of the `LAMMPS web site <https://www.lammps.org/movies.html>`_.
 
 There are two kinds of sub-directories in the examples folder.  Lower
 case named directories contain one or a few simple, quick-to-run
@@ -108,6 +108,8 @@ Lowercase directories
 +-------------+------------------------------------------------------------------+
 | msst        | MSST shock dynamics                                              |
 +-------------+------------------------------------------------------------------+
+| multi       | multi neighboring for systems with large interaction disparities |
++-------------+------------------------------------------------------------------+
 | nb3b        | use of non-bonded 3-body harmonic pair style                     |
 +-------------+------------------------------------------------------------------+
 | neb         | nudged elastic band (NEB) calculation for barrier finding        |
@@ -164,7 +166,7 @@ Here is how you can run and visualize one of the sample problems:
 Running the simulation produces the files *dump.indent* and
 *log.lammps*\ .  You can visualize the dump file of snapshots with a
 variety of third-party tools highlighted on the
-`Visualization <https://lammps.sandia.gov/viz.html>`_ page of the LAMMPS
+`Visualization <https://www.lammps.org/viz.html>`_ page of the LAMMPS
 web site.
 
 If you uncomment the :doc:`dump image <dump_image>` line(s) in the input

doc/src/Howto.rst

@@ -3,7 +3,7 @@ Howto discussions
 
 These doc pages describe how to perform various tasks with LAMMPS,
 both for users and developers.  The
-`glossary <https://lammps.sandia.gov/glossary.html>`_ website page also lists MD
+`glossary <https://www.lammps.org/glossary.html>`_ website page also lists MD
 terminology with links to corresponding LAMMPS manual pages.  The
 example input scripts included in the examples directory of the LAMMPS
 distribution and highlighted on the :doc:`Examples <Examples>` doc page
@@ -23,6 +23,7 @@ General howto
    Howto_library
    Howto_couple
    Howto_client_server
+   Howto_mdi
 
 Settings howto
 ==============

doc/src/Howto_bioFF.rst

@@ -91,6 +91,7 @@ documentation for the formula it computes.
 * :doc:`bond_style <bond_harmonic>` harmonic
 * :doc:`bond_style <bond_morse>` morse
 
+* :doc:`angle_style <angle_cosine_squared>` cosine/squared
 * :doc:`angle_style <angle_harmonic>` harmonic
 * :doc:`angle_style <angle_cosine>` cosine
 * :doc:`angle_style <angle_cosine_periodic>` cosine/periodic

doc/src/Howto_cmake.rst

@@ -296,6 +296,8 @@ Some common CMake variables
      - Description
    * - ``CMAKE_INSTALL_PREFIX``
      - root directory of install location for ``make install``  (default: ``$HOME/.local``)
+   * - ``LAMMPS_INSTALL_RPATH``
+     - set or remove runtime path setting from binaries for ``make install`` (default: ``off``)
    * - ``CMAKE_BUILD_TYPE``
      - controls compilation options:
        one of ``RelWithDebInfo`` (default), ``Release``, ``Debug``, ``MinSizeRel``
@@ -409,10 +411,10 @@ interface (``ccmake`` or ``cmake-gui``).
 .. note::
 
    Using a preset to select a compiler package (``clang.cmake``,
-   ``gcc.cmake``, or ``intel.cmake``) are an exception to the option
+   ``gcc.cmake``, ``intel.cmake``, ``oneapi.cmake``, or ``pgi.cmake``)
-   of updating the configuration incrementally, as they will trigger
+   are an exception to the mechanism of updating the configuration incrementally,
-   a reset of cached internal CMake settings and thus reset them to
+   as they will trigger a reset of cached internal CMake settings and thus
-   their default values.
+   reset settings to their default values.
 
 Compilation and build targets
 -----------------------------

doc/src/Howto_drude.rst

@@ -42,10 +42,11 @@ screening. It may be necessary to use the *extra/special/per/atom*
 keyword of the :doc:`read_data <read_data>` command. If using :doc:`fix shake <fix_shake>`, make sure no Drude particle is in this fix
 group.
 
-There are two ways to thermostat the Drude particles at a low
+There are three ways to thermostat the Drude particles at a low
 temperature: use either :doc:`fix langevin/drude <fix_langevin_drude>`
 for a Langevin thermostat, or :doc:`fix drude/transform/\* <fix_drude_transform>` for a Nose-Hoover
-thermostat. The former requires use of the command :doc:`comm_modify vel yes <comm_modify>`. The latter requires two separate integration
+thermostat, or :doc:`fix tgnvt/drude <fix_tgnh_drude>` for a temperature-grouped Nose-Hoover thermostat.
+The first and third require use of the command :doc:`comm_modify vel yes <comm_modify>`. The second requires two separate integration
 fixes like *nvt* or *npt*\ . The correct temperatures of the reduced
 degrees of freedom can be calculated using the :doc:`compute temp/drude <compute_temp_drude>`. This requires also to use the
 command *comm_modify vel yes*.

doc/src/Howto_drude2.rst

@@ -9,6 +9,8 @@ USER-DRUDE package activated. Then, the data file and input scripts
 have to be modified to include the Drude dipoles and how to handle
 them.
 
+Example input scripts available: examples/USER/drude
+
 ----------
 
 **Overview of Drude induced dipoles**
@@ -36,7 +38,7 @@ polarizability :math:`\alpha` by
 
 Ideally, the mass of the Drude particle should be small, and the
 stiffness of the harmonic bond should be large, so that the Drude
-particle remains close ot the core. The values of Drude mass, Drude
+particle remains close to the core. The values of Drude mass, Drude
 charge, and force constant can be chosen following different
 strategies, as in the following examples of polarizable force
 fields:
@@ -221,6 +223,14 @@ modification of forces but no position/velocity updates), the fix
 
    fix NVE all nve
 
+To avoid the flying ice cube artifact, where the atoms progressively freeze and the
+center of mass of the whole system drifts faster and faster, the *fix momentum*
+can be used. For instance:
+
+.. code-block:: LAMMPS
+
+   fix MOMENTUM all momentum 100 linear 1 1 1
+
 Finally, do not forget to update the atom type elements if you use
 them in a *dump_modify ... element ...* command, by adding the element
 type of the DPs. Here for instance
@@ -376,14 +386,7 @@ For our phenol example, the groups would be defined as
 
 Note that with the fixes *drude/transform*\ , it is not required to
 specify *comm_modify vel yes* because the fixes do it anyway (several
-times and for the forces also).  To avoid the flying ice cube artifact
+times and for the forces also).
-:ref:`(Lamoureux and Roux) <Lamoureux2>`, where the atoms progressively freeze and the
-center of mass of the whole system drifts faster and faster, the *fix
-momentum* can be used. For instance:
-
-.. code-block:: LAMMPS
-
-   fix MOMENTUM all momentum 100 linear 1 1 1
 
 It is a bit more tricky to run a NPT simulation with Nose-Hoover
 barostat and thermostat.  First, the volume should be integrated only
@@ -404,6 +407,31 @@ instructions for thermostatting and barostatting will look like
    fix NVT DRUDES nvt temp 1. 1. 20
    fix INVERSE all drude/transform/inverse
 
+Another option for thermalizing the Drude model is to use the
+temperature-grouped Nose-Hoover (TGNH) thermostat proposed by :ref:`(Son) <TGNH-SON>`.
+This is implemented as :doc:`fix tgnvt/drude <fix_tgnh_drude>` and :doc:`fix tgnpt/drude <fix_tgnh_drude>`.
+It separates the kinetic energy into three contributions:
+the molecular center of mass (COM) motion, the motion of atoms or atom-Drude pairs relative to molecular COMs,
+and the relative motion of atom-Drude pairs.
+An independent Nose-Hoover chain is applied to each type of motion.
+When TGNH is used, the temperatures of molecular, atomic and Drude motion can be printed out with :doc:`thermo_style` command.
+
+NVT simulation with TGNH thermostat
+
+.. code-block:: LAMMPS
+
+   comm_modify vel yes
+   fix TGNVT all tgnvt/drude temp 300. 300. 100 1. 20
+   thermo_style custom f_TGNVT[1] f_TGNVT[2] f_TGNVT[3]
+
+NPT simulation with TGNH thermostat
+
+.. code-block:: LAMMPS
+
+   comm_modify vel yes
+   fix TGNPT all tgnpt/drude temp 300. 300. 100 1. 20 iso 1. 1. 500
+   thermo_style custom f_TGNPT[1] f_TGNPT[2] f_TGNPT[3]
+
 ----------
 
 **Rigid bodies**
@@ -480,3 +508,7 @@ NPT ensemble using Nose-Hoover thermostat:
 
 **(SWM4-NDP)** Lamoureux, Harder, Vorobyov, Roux, MacKerell, Chem Phys
 Let, 418, 245-249 (2006)
+
+.. _TGNH-Son:
+
+**(Son)** Son, McDaniel, Cui and Yethiraj, J Phys Chem Lett, 10, 7523 (2019).

doc/src/Howto_github.rst

@@ -72,7 +72,7 @@ explained in more detail here: `feature branch workflow <https://www.atlassian.c
 
 **Feature branches**
 
-First of all, create a clone of your version on github on your local
+First of all, create a clone of your version on GitHub on your local
 machine via HTTPS:
 
 .. code-block:: bash
@@ -155,7 +155,7 @@ useful message that explains the change.
 
 .. code-block:: bash
 
-     $ git commit -m 'Finally updated the github tutorial'
+     $ git commit -m 'Finally updated the GitHub tutorial'
 
 After the commit, the changes can be pushed to the same branch on GitHub:
 

doc/src/Howto_granular.rst

@@ -18,12 +18,13 @@ This compute
 
 calculates rotational kinetic energy which can be :doc:`output with thermodynamic info <Howto_output>`.
 
-Use one of these 3 pair potentials, which compute forces and torques
+Use one of these 4 pair potentials, which compute forces and torques
 between interacting pairs of particles:
 
-* :doc:`pair_style <pair_style>` gran/history
+* :doc:`pair_style gran/history <pair_gran>`
-* :doc:`pair_style <pair_style>` gran/no_history
+* :doc:`pair_style gran/no_history <pair_gran>`
-* :doc:`pair_style <pair_style>` gran/hertzian
+* :doc:`pair_style gran/hertzian <pair_gran>`
+* :doc:`pair_style granular <pair_granular>`
 
 These commands implement fix options specific to granular systems:
 
@@ -31,6 +32,7 @@ These commands implement fix options specific to granular systems:
 * :doc:`fix pour <fix_pour>`
 * :doc:`fix viscous <fix_viscous>`
 * :doc:`fix wall/gran <fix_wall_gran>`
+* :doc:`fix wall/gran/region <fix_wall_gran_region>`
 
 The fix style *freeze* zeroes both the force and torque of frozen
 atoms, and should be used for granular system instead of the fix style

doc/src/Howto_mdi.rst

@@ -0,0 +1,132 @@
+Using LAMMPS with the MDI library for code coupling
+===================================================
+
+.. note::
+
+  This Howto doc page will eventually replace the
+  :doc:`Howto client/server <Howto_client_server>` doc page.
+
+Client/server coupling of two codes is where one code is the "client"
+and sends request messages (data) to a "server" code.  The server
+responds to each request with a reply message.  This enables the two
+codes to work in tandem to perform a simulation.  LAMMPS can act as
+either a client or server code; it does this by using the `MolSSI
+Driver Interface (MDI) library
+<https://molssi-mdi.github.io/MDI_Library/html/index.html>`_,
+developed by the `Molecular Sciences Software Institute (MolSSI)
+<https://molssi.org>`_.
+
+Alternate methods for code coupling with LAMMPS are described on the
+:doc:`Howto couple <Howto_couple>` doc page.
+
+Some advantages of client/server coupling are that the two codes can run
+as stand-alone executables; they need not be linked together.  Thus
+neither code needs to have a library interface.  This also makes it easy
+to run the two codes on different numbers of processors.  If a message
+protocol (format and content) is defined for a particular kind of
+simulation, then in principle any code which implements the client-side
+protocol can be used in tandem with any code which implements the
+server-side protocol.  Neither code needs to know what specific other
+code it is working with.
+
+In MDI nomenclature, a client code is the "driver", and a server code is
+an "engine".  One driver code can communicate with one or more instances
+of one or more engine codes.  Driver and engine codes can be written in
+any language: C, C++, Fortran, Python, etc.
+
+In addition to allowing driver and engine(s) running to run as
+stand-alone executables, MDI also enables a server code to be a
+"plugin" to the client code.  In this scenario, server code(s) are
+compiled as shared libraries, and one (or more) instances of the
+server are instantiated by the driver code.  If the driver code runs
+in parallel, it can split its MPI communicator into multiple
+sub-communicators, and launch each plugin engine instance on a
+sub-communicator.  Driver processors in that sub-communicator exchange
+messages with that engine instance, and can also send MPI messages to
+other processors in the driver.  The driver code can also destroy
+engine instances and re-instantiate them.
+
+The way that a driver communicates with an engine is by making
+MDI_Send() and MDI_Recv() calls, which are conceptually similar to
+MPI_Send() and MPI_Recv() calls.  Each send or receive has a string
+which identifies the command name, and optionally some data, which can
+be a single value or vector of values of any data type.  Inside the
+MDI library, data is exchanged between the driver and engine via MPI
+calls or sockets.  This a run-time choice by the user.
+
+-------------
+
+As an example, LAMMPS and the ``pw.x`` command from Quantum Espresso (a
+suite of quantum DFT codes), can work together via the MDI library to
+perform an ab initio MD (AIMD) simulation, where LAMMPS runs an MD
+simulation and sends a message each timestep to ``pw.x`` asking it to
+compute quantum forces on the current configuration of atoms.  Here is
+how the 2 codes are launched to communicate by MPI:
+
+.. code-block:: bash
+
+   % mpirun -np 2 lmp_mpi -mdi "-role DRIVER -name d -method MPI" \
+     -in in.aimd : -np 16 pw.x -in qe.in -mdi "-role ENGINE -name e -method MPI"
+
+In this case LAMMPS runs on 2 processors (MPI tasks), ``pw.x`` runs on 16
+processors.
+
+Here is how the 2 codes are launched to communicate by sockets:
+
+.. code-block:: bash
+
+   % mpirun -np 2 lmp_mpi -mdi "-role DRIVER -name d -method TCP -port 8021" -in in.aimd
+   % mpirun -np 16 pw.x -in qe.in -mdi "-role ENGINE -name e -method TCP -port 8021 -hostname localhost"
+
+These commands could be issued in different windows on a desktop
+machine.  Or in the same window, if the first command is ended with
+"&" so as to run in the background.  If "localhost" is replaced by an
+IP address, ``pw.x`` could be run on another machine on the same network, or
+even on another machine across the country.
+
+After both codes initialize themselves to model the same system, this is
+what occurs each timestep:
+
+* LAMMPS send a ">COORDS" message to ``pw.x`` with a 3*N vector of current atom coords
+* ``pw.x`` receives the message/coords and computes quantum forces on all the atoms
+* LAMMPS send a "<FORCES" message to ``pw.x`` and waits for the result
+* ``pw.x`` receives the message (after its computation finishes) and sends a 3*N vector of forces
+* LAMMPS receives the forces and time integrates to complete a single timestep
+
+-------------
+
+Examples scripts for using LAMMPS as an MDI engine are in the
+examples/mdi directory.  See the README file in that directory for
+instructions on how to run the examples.
+
+.. note::
+
+  Work is underway to add commands that allow LAMMPS to be used as an
+  MDI driver, e.g. for the AIMD example discussed above.  Example
+  scripts for this usage mode will be added the same directory when
+  available.
+
+If LAMMPS is used as a stand-alone engine it should set up the system
+it will be modeling in its input script, then invoke the
+:doc:`mdi/engine <mdi_engine>` command.  This will put LAMMPS into
+"engine mode" where it waits for messages and data from the driver.
+When the driver sends an "EXIT" command, LAMMPS will exit engine mode
+and the input script will continue.
+
+If LAMMPS is used as a plugin engine it operates the same way, except
+that the driver will pass LAMMPS an input script to initialize itself.
+Upon receiving the "EXIT" command, LAMMPS will exit engine mode and the
+input script will continue.  After finishing execution of the input
+script, the instance of LAMMPS will be destroyed.
+
+LAMMPS supports the full set of MD-appropriate engine commands defined
+by the MDI library.  See the :doc:`mdi/engine <mdi_engine>` doc page for
+a list of these.
+
+If those commands are not sufficient for a user-developed driver to use
+LAMMPS as an engine, then new commands can be easily added.  See these
+two files which implement the definition of MDI commands and the logic
+for responding to them:
+
+* src/MDI/mdi_engine.cpp
+* src/MDI/fix_mdi_engine.cpp

doc/src/Howto_pylammps.rst

@@ -9,8 +9,8 @@ Overview
 ``PyLammps`` is a Python wrapper class for LAMMPS which can be created
 on its own or use an existing lammps Python object.  It creates a simpler,
 more "pythonic" interface to common LAMMPS functionality, in contrast to
-the ``lammps.py`` wrapper for the C-style LAMMPS library interface which
+the ``lammps`` wrapper for the C-style LAMMPS library interface which
-is written using `Python ctypes <ctypes_>`_.  The ``lammps.py`` wrapper
+is written using `Python ctypes <ctypes_>`_.  The ``lammps`` wrapper
 is discussed on the :doc:`Python_head` doc page.
 
 Unlike the flat ``ctypes`` interface, PyLammps exposes a discoverable