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lammps/doc/src/Howto_bioFF.txt
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"Higher level section"_Howto.html - "LAMMPS WWW Site"_lws - "LAMMPS
Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)
:line
CHARMM, AMBER, and DREIDING force fields :h3
A force field has 2 parts: the formulas that define it and the
coefficients used for a particular system. Here we only discuss
formulas implemented in LAMMPS that correspond to formulas commonly
used in the CHARMM, AMBER, and DREIDING force fields. Setting
coefficients is done in the input data file via the
"read_data"_read_data.html command or in the input script with
commands like "pair_coeff"_pair_coeff.html or
"bond_coeff"_bond_coeff.html. See the "Tools"_Tools.html doc page for
additional tools that can use CHARMM or AMBER to assign force field
coefficients and convert their output into LAMMPS input.
See "(MacKerell)"_#howto-MacKerell for a description of the CHARMM force
field. See "(Cornell)"_#howto-Cornell for a description of the AMBER force
field.
:link(charmm,http://www.scripps.edu/brooks)
:link(amber,http://amber.scripps.edu)
These style choices compute force field formulas that are consistent
with common options in CHARMM or AMBER. See each command's
documentation for the formula it computes.
"bond_style"_bond_harmonic.html harmonic
"angle_style"_angle_charmm.html charmm
"dihedral_style"_dihedral_charmm.html charmmfsh
"dihedral_style"_dihedral_charmm.html charmm
"pair_style"_pair_charmm.html lj/charmmfsw/coul/charmmfsh
"pair_style"_pair_charmm.html lj/charmmfsw/coul/long
"pair_style"_pair_charmm.html lj/charmm/coul/charmm
"pair_style"_pair_charmm.html lj/charmm/coul/charmm/implicit
"pair_style"_pair_charmm.html lj/charmm/coul/long :ul
"special_bonds"_special_bonds.html charmm
"special_bonds"_special_bonds.html amber :ul
NOTE: For CHARMM, newer {charmmfsw} or {charmmfsh} styles were
released in March 2017. We recommend they be used instead of the
older {charmm} styles. See discussion of the differences on the "pair
charmm"_pair_charmm.html and "dihedral charmm"_dihedral_charmm.html
doc pages.
DREIDING is a generic force field developed by the "Goddard
group"_http://www.wag.caltech.edu at Caltech and is useful for
predicting structures and dynamics of organic, biological and
main-group inorganic molecules. The philosophy in DREIDING is to use
general force constants and geometry parameters based on simple
hybridization considerations, rather than individual force constants
and geometric parameters that depend on the particular combinations of
atoms involved in the bond, angle, or torsion terms. DREIDING has an
"explicit hydrogen bond term"_pair_hbond_dreiding.html to describe
interactions involving a hydrogen atom on very electronegative atoms
(N, O, F).
See "(Mayo)"_#howto-Mayo for a description of the DREIDING force field
These style choices compute force field formulas that are consistent
with the DREIDING force field. See each command's
documentation for the formula it computes.
"bond_style"_bond_harmonic.html harmonic
"bond_style"_bond_morse.html morse :ul
"angle_style"_angle_harmonic.html harmonic
"angle_style"_angle_cosine.html cosine
"angle_style"_angle_cosine_periodic.html cosine/periodic :ul
"dihedral_style"_dihedral_charmm.html charmm
"improper_style"_improper_umbrella.html umbrella :ul
"pair_style"_pair_buck.html buck
"pair_style"_pair_buck.html buck/coul/cut
"pair_style"_pair_buck.html buck/coul/long
"pair_style"_pair_lj.html lj/cut
"pair_style"_pair_lj.html lj/cut/coul/cut
"pair_style"_pair_lj.html lj/cut/coul/long :ul
"pair_style"_pair_hbond_dreiding.html hbond/dreiding/lj
"pair_style"_pair_hbond_dreiding.html hbond/dreiding/morse :ul
"special_bonds"_special_bonds.html dreiding :ul
:line
:link(howto-MacKerell)
[(MacKerell)] MacKerell, Bashford, Bellott, Dunbrack, Evanseck, Field,
Fischer, Gao, Guo, Ha, et al, J Phys Chem, 102, 3586 (1998).
:link(howto-Cornell)
[(Cornell)] Cornell, Cieplak, Bayly, Gould, Merz, Ferguson,
Spellmeyer, Fox, Caldwell, Kollman, JACS 117, 5179-5197 (1995).
:link(howto-Mayo)
[(Mayo)] Mayo, Olfason, Goddard III, J Phys Chem, 94, 8897-8909
(1990).