# LAMMPS Input file for simulating pure propane with OPLS-AA forcefield

# let's try real units now
units            real
atom_style       full

kspace_style     pppm 1.0e-5 
pair_style       lj/cut/coul/long 10.5
bond_style       harmonic
angle_style      harmonic
dihedral_style   opls
special_bonds    lj/coul 0.0 0.0 0.5

read_data        FilledConfig.data

# Force field parameters -- taken from OPLS-AA
pair_coeff       1 2 4.4514E-02 2.958 #C-H
pair_coeff       1 1 6.6021E-02 3.500 #C-C
pair_coeff       2 2 3.0013E-02 2.500 #H-H

# Use the CHARMM/22 parameters rather than the AMBER ones 
bond_coeff         1 268.0 1.529 #C-C
bond_coeff         2 340.0 1.090 #C-H

angle_coeff        1 58.35 112.7 # C-C-C
angle_coeff        2 37.50 110.7 # C-C-H
angle_coeff        3 33.00 107.8 # H-C-H

dihedral_coeff     1 0 0 0.318 0 # H-C-C-H
dihedral_coeff     2 0 0 0.366 0 # C-C-C-H

velocity           all create 298.0 1335 dist gaussian

neighbor           3.5 bin
neigh_modify       delay 0 every 1 check yes

# 1 femntoseconds for outtermost loop (all intermolecular stuff)
timestep           1.0
# let's try RESPA, timestep for intramolecular stuff is 1.0/3 = 0.33 fs
run_style          respa 2 1

# Run npt, 41.94 atm and 298K
fix                1 all npt 298.0 298.0 100.0 xyz 41.94 41.94 100.0
dump               2 all xyz 5000 nve.xyz

thermo             100
run                10000