I am running a polymer melt with a rigid NP, if I ran the same data file but only considering the pure melt, it does not break any fene bond(runs OK), but when I add the static NP, bonds start breaking:
These are my settings:
dimension 3
boundary p p p
atom_style bond
units lj
read_data test.dat
#potentials
bond_style fene #set bond forces
bond_coeff 1 30 1.5 1.0 1.0 #k r0 epsilon sigma
pair_style lj/cut 2.5 #repulsive backbone
pair_modify shift yes
pair_coeff 1 1 1.0 1.0 #epsilon sigma cutoff
pair_coeff 1 2 1.414213 1.0
pair_coeff 2 2 2 1.0 1.0
special_bonds lj 0.0 1.0 1.0
# define groups
group chain type 1
group NP type 2
# main settings
lattice sc 1.0
velocity NP set 0.0 0.0 0.0
fix 1 NP setforce 0.0 0.0 0.0
fix 2 chain nvt temp 1.0 1.0 100.0
thermo_style custom step temp press pe ke etotal
thermo 10
log test.log
dump 1 NP xyz 10 NP.xyz
dump 2 chain xyz 10 chain.xyz
run_style respa 2 3 bond 1 pair 2
timestep 0.006
run 9000000
which gives:
Step Temp Press PotEng KinEng TotEng
0 1.3999861 36.569383 21.241205 2.0990878 23.340292
WARNING: FENE bond too long: 1 249 250 1.60859 (bond_fene.cpp:91)
WARNING: FENE bond too long: 1 250 251 1.55776 (bond_fene.cpp:91)
WARNING: FENE bond too long: 1 249 250 3.19365 (bond_fene.cpp:91)
ERROR on proc 0: Bad FENE bond (bond_fene.cpp:92)
Any idea, what is wrong?
Thanks,
BP