lammps/tools/moltemplate/common/watmw.lt

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# This file stores LAMMPS data for the "mW" water model.
# (Molinero, V. and Moore, E.B., J. Phys. Chem. B 2009, 113, 4008-4016)
#
# In this model, each water molecule is represented by a single "mW" particle.
# These particles interact with their neighbors via 3-body Stillinger-Weber
# forces whose parameters are tuned to mimic directional hydrogen-bonding
# in liquid water (as well as hexagonal ice, type II ice, and
# low-density super-cooled liquid/amorphous water phases).
####
#
# NOTE: THIS FILE IS INTENDED FOR SIMULATIONS OF PURE WATER ONLY.
# IF YOU HAVE OTHER ATOMS IN YOUR SYSTEM (BESIDES WATER),
# YOU MUST REPLACE THIS LINE:
#
# pair_coeff * * sw system.in.sw mW
#
# WITH THIS LINE:
#
# pair_coeff * * sw system.in.sw mW NULL NULL NULL
#
# ...IN THE FILE BELOW.
#
# (Note:The number of "NULL" entries in the list should match the
# number of other atom types defined somewhere in your simulation.
# In the "3bodyWater+hydrocarbons_MW+TraPPE" example, there are 3
# types of carbon defined in "trappe1998.lt", so "NULL" appears 3 times.
####
WatMW {
write("Data Atoms") {
$atom:mW $mol:. @atom:mW 0.0 0.0 0.0 0.0
}
write_once("Data Masses") {
@atom:mW 18.02
}
write_once("system.in.sw") {
mW mW mW 6.189 2.3925 1.8 23.15 1.2 -0.333333333 7.049556277 0.602224558 4 0 0
}
write_once("In Init") {
# -- Default styles for "WatMW" --
units real
pair_style sw
}
write_once("In Settings") {
# --Now indicate which atom type(s) are simulated using the "sw" pair style
# -- In this case only one of the atom types is used (the mW water "atom").
pair_coeff * * sw system.in.sw mW # SEE COMMENT ABOVE
# -- Unfortunately LAMMPS itself does not understand molemlate syntax, so
# -- the atoms are identified by order in the list, not by name. (The "mW"
# -- refers to to an identifier in the system.in.sw file, not watmw.lt.)
# -- This command says that the first atom type corresponds to the "mW"
# -- atom in system.in.sw, and to ignore the remaining three atom types
# -- (correspond to the CH2, CH3, CH4 atom types defined in trappe1998.lt.
# -- We don't want to use the "sw" force field for interactions involving
# -- these atom types, so we put "NULL" there.)
# -- Note: For this to work, you should probably run moltemplate this way:
# -- moltemplate.sh -a "@atom:WatMW/mW 1" system.lt
# -- This assigns the atom type named @atom:WatMW/mW to 1 (the first atom)
}
# -- optional --
write_once("In Settings") {
group WatMW type @atom:mW #(Atoms of this type belong to the "WatMW" group)
}
} # WatMW