# This is LAMMPS input script specifies a simple DPD simulation.
# It reproduces Fig. 2 of Groot and Warren, J. Chem. Phys. 107,
# 4423 (1997)

units       lj
atom_style full
comm_modify vel yes
pair_style  dpd 1.0 1.0 34387

read_data bilayer.data
# create simulation box
#lattice     fcc 3
#region      mybox block -4 4 -4 4 -4 4 units lattice
#create_box  1 mybox
#create_atoms    1 box

# define masses and interaction coefficient
#mass        * 1
pair_coeff  1 1 10 4.5
pair_coeff  2 2 30 4.5
pair_coeff  3 3 25 4.5
pair_coeff  1 2 35 4.5
pair_coeff  1 3 75 4.5
pair_coeff  2 3 30 4.5

bond_style harmonic
bond_coeff 1 128.0 0.5

angle_style cosine/delta
angle_coeff 1 7.5 180.0

# create initial velocities
velocity    all create 1.0 4928459 dist gaussian

# change neighbor list parameters to avoid dangerous builds
neighbor    2.0 bin
neigh_modify    delay 3

# specify simulation parameters
timestep    0.04
thermo      10

# first equilibrate the initial condition
fix     1 all nve
run     500

dump traj all xtc  50 traj.xtc
dump_modify traj unwrap yes

dump traj_xyz all xyz 50 traj.xyz

# production run
run     50000