Hi,
I am trying to run a 2 chain system, bead-spring polymer model. Trying
to run it in 3 stages: 1st soft potential, 2nd lj potential with
attractive and repulsive chains, 3rd all attractive chains. First
stage running well, but in second stage, FENE bonds become too long.
Following is the input file, can somebody please see what's wrong!!
Thanks,
Monojoy
SP_2step.inp
# Bead-spring polymer simulation
# use soft potential to un-overlap, follow with FENE potential
units lj
atom_style bond
neighbor 0.3 bin
neigh_modify every 1 delay 10
# soft potential start-up in one stage
read_data dataSP2.chain
special_bonds 0.0 1.0 1.0
bond_style fene
bond_coeff 1 30.0 1.5 2.0 1.0
bond_coeff 2 30.0 1.5 4.0 1.0
pair_style soft 2.5
pair_coeff 1 1 1.0 30.0
pair_coeff 2 2 1.0 30.0
pair_coeff 1 2 1.0 30.0
velocity all create 1.0 2349852 rot yes dist gaussian
fix 1 all nve 0.1
fix 2 all langevin 1.0 1.0 10.0 904297
timestep 0.006
thermo 100
run 100000
# Run with LJ potentials to form the PDMS droplet
bond_style fene
bond_coeff 1 30.0 1.5 2.0 1.0
bond_coeff 2 30.0 1.5 4.0 1.0
pair_style lj/cut 2.5
pair_modify shift yes mix arithmetic
pair_coeff 1 1 2.0 1.0 1.12246
pair_coeff 2 2 4.0 1.0 2.5
thermo 100
dump 1 all xyz 10000 dump01.xyz
timestep 0.012
reset_timestep 0
run 10000
# MAIN RUN with LJ
bond_style fene
bond_coeff 1 30.0 1.5 2.0 1.0
bond_coeff 2 30.0 1.5 4.0 1.0
pair_style lj/cut 2.5
pair_modify shift yes mix arithmetic
pair_coeff 1 1 2.0 1.0 2.5
pair_coeff 2 2 4.0 1.0 2.5
thermo 100
dump 2 all xyz 10000 dump02.xyz
timestep 0.012
reset_timestep 0
run 10000