breaking a harmonic bond

Dear all,

I am attempting to break a harmonic between one time-integrated and one non-time integrated particle. I would like to know whether this is a reasonable solution to this problem as I only need my harmonic bond which is broken after specified distance.

Thanks in advance for any input! Anna

units lj
atom_style full
dimension 3
neighbor 0.5 bin
neigh_modify every 1 delay 3 check yes
neigh_modify exclude type 1 2
neigh_modify exclude type 1 1
neigh_modify exclude type 2 2
atom_modify sort 0 0
boundary p p p

read_data harmonic.dat

group sample type 1

velocity all create 1.0 482748 dist uniform

thermo 50
thermo_style one
timestep 0.01

fix 1 sample langevin 1.0 1.0 10.0 12345
fix 2 sample nve
fix 5 all bond/break 10 1 2
pair_style none
bond_style harmonic
bond_coeff 1 10 1
special_bonds fene
delete_bonds all bond 0 remove
delete_bonds all bond fene remove
delete_bonds all stats
dump 1 all custom 1000 data_harmonic.dump id x y z ix iy iz
dump_modify 1 format ā€œd .5f .5f .5f %d %d %dā€
f
run 3000000

Dear all,

I am attempting to break a harmonic between one time-integrated and one
non-time integrated particle. I would like to know whether this is a
reasonable solution to this problem as I only need my harmonic bond which is
broken after specified distance.

Thanks in advance for any input! Anna

this sounds a lot like you want something akin to this:

http://lammps.sandia.gov/doc/bond_quartic.html

axel.

If you know the bond(s) you want to break, just
use delete_bonds. Earlier you asked about
the special_bond settings when you do that.
I don't see that it mattters, you can set them
before or after to anything you want.

If you want the bond to break dynamically
during a run, based on a criterion like
distance, then you can use
bond_style quartic or fix bond/break.
But those are not harmonic bonds.

Steve