Bond dissociation of a polymer under tension

Hi all,

I am simulating a polymer system under tension using lammps (ver. 7 Aug 2019). I have used
fix bond/break command with a cutoff to break the bond. Is it possible to print the information on which bonds are broken during the simulation to a file ?

Thank you,
Diljith T.

Hi all,

I am simulating a polymer system under tension using lammps (ver. 7 Aug 2019). I have used
fix bond/break command with a cutoff to break the bond. Is it possible to print the information on which bonds are broken during the simulation to a file ?

you can output the current list of (explicit) bonds (and some of their properties) using “compute bond/local” and then output them using dump style local.

axel.

Thank you for your response.

From the compute property/local command doc page:

For bonds and angles, a bonds/angles that have been broken by setting their bond/angle type to 0 will not be included. Bonds/angles that have been turned off (see the fix shake or delete_bonds commands) by setting their bond/angle type negative are written into the file. This is consistent with the compute bond/local and compute angle/local commands.

So in other words, the list of broken bonds is your original set of bonds
(e.g. the data file) minus what appears in the list when you do dump local. With dump local
you can use compute property/local
to also dump the IDs of the 2 atoms in the bond.

It’s possible doing a write_data will also not include broken bonds. Not sure.

I can’t think of an easier way to get the (presumably small) set of broken
bonds.

Steve

Thank you.