Homec4science
Diffusion lammps (lammps-icms) Browse

lammps/tools/moltemplate/common/tip3p_2004.lt
4a1807d39739lammps-icms

Last Change
Raw File

tip3p_2004.lt
View Options

#########################################################
# Warning: This file has not been carefully tested.
#########################################################
# There are two different versions of TIP3P:
#
# tip3p_1983.lt # The implementation of TIP3P used by CHARMM (I think).
# tip3p_2004.lt # The newer Price & Brooks, J. Chem Phys 2004 model
# # which uses long-range coulombics
#########################################################
# file "tip3p_2004.lt"
#
# H1 H2
# \ /
# O
#
# I think this is the TIP3P water described in the paper by
# Daniel J. Price and Charles L. Brooks III
# J. Chem. Phys., 121(20): 10096 (2004)
# Specifically I think it refers to the "Model B" version of long-range TIP3P
# described in the 3rd-to-last column of "Table I", on p.10099.
TIP3P_2004 {
write_once("In Init") {
# -- Default styles (for solo "TIP3P_2004" water) --
units real
atom_style full
pair_style hybrid lj/charmm/coul/long 10.0 10.5 10.5
bond_style hybrid harmonic
angle_style hybrid harmonic
kspace_style pppm 0.0001
pair_modify mix arithmetic
}
write("Data Atoms") {
$atom:O $mol:. @atom:ow -0.830 0.0000000 0.00000 0.000000
$atom:H1 $mol:. @atom:hw 0.415 0.756950327 0.00000 0.5858822766
$atom:H2 $mol:. @atom:hw 0.415 -0.756950327 0.00000 0.5858822766
}
write_once("Data Masses") {
@atom:ow 15.9994
@atom:hw 1.008
}
write("Data Bonds") {
$bond:OH1 @bond:OH $atom:O $atom:H1
$bond:OH2 @bond:OH $atom:O $atom:H2
}
write("Data Angles") {
$angle:HOH @angle:HOH $atom:H1 $atom:O $atom:H2
}
write_once("In Settings") {
bond_coeff @bond:OH harmonic 450.0 0.9572
angle_coeff @angle:HOH harmonic 55.0 104.52
#########################################################################
#### There are two choices for for the O-O interactions
#########################################################################
#### O-O nonbonded interactions
# For the 1983 Jorgensen version of TIP3P use:
# pair_coeff @atom:ow @atom:ow lj/charmm/coul/charmm 0.1521 3.1507
# For the 2004 Price & Brooks version of TIP3P use:
pair_coeff @atom:ow @atom:ow lj/charmm/coul/long 0.102 3.188
#########################################################################
#### There are three choices for for the O-H and H-H interactions
#########################################################################
#### 1) CHARMM uses an arithmetic mixing-rule for the O-H sigma parameter
pair_coeff @atom:hw @atom:hw lj/charmm/coul/long 0.0460 0.4000
pair_coeff @atom:ow @atom:hw lj/charmm/coul/long 0.0836 1.7753 #arithmetic
#########################################################################
#### 2) OPLS-AA uses geometric a mixing-fule for the O-H sigma parameter,
#### If you want to use this, uncomment the following two lines:
# pair_coeff @atom:hw @atom:hw lj/charmm/coul/charmm 0.0460 0.4000
# pair_coeff @atom:ow @atom:hw lj/charmm/coul/charmm 0.0836 1.1226 #geometric
#########################################################################
#### 3) The original Jorgensen 1983 parameterization has no OH or HH
# lennard-jones interactions. For this behavior, uncomment these lines:
# pair_coeff @atom:hw @atom:hw lj/charmm/coul/charmm 0.00 0.4000
# pair_coeff @atom:ow @atom:hw lj/charmm/coul/charmm 0.00 1.7753
#########################################################################
# Define a group for the tip3p water molecules:
group tip3p type @atom:ow @atom:hw
# Optional: Constrain the angles and distances.
# (Most implementations use this, but it is optional.)
fix fShakeTIP3P tip3p shake 0.0001 10 100 b @bond:OH a @angle:HOH
# (Remember to "unfix" fShakeTIP3P during minimization.)
}
} # "TIP3P_2004" water molecule type
c4science · Help