units           lj

atom_style      full

boundary p p p

special_bonds lj/coul 1 1 1

newton on on

# save an extra atom type for bond particles

read_data data.chain

neighbor        2.0 bin

neigh_modify    every 10 check yes

bond_style      harmonic

bond_coeff      * 225.0 0.85

comm_modify vel yes

# must use pair hybrid, since srp bond particles

# do not interact with other atoms types

pair_style      hybrid dpd 1.0 1.0 373692 srp 0.8 1 mid

pair_coeff      1 1 dpd 60.0 4.5 1.0 

pair_coeff      1 2 none

pair_coeff      2 2 srp 100.0 

# auto normalization of thermo quantites is turned off by pair srp

# just divide by natoms 

variable        natoms equal count(all)

variable        nPotEng equal c_thermo_pe/v_natoms 

thermo 50

thermo_style custom step temp pe v_nPotEng press atoms v_natoms lx ly lz

fix  1 all nve

timestep        0.01

run          1000