[lammps-users] Question about AIREBO

Dear LAMMPS users,
I am having trouble with pair_style AIREBO within LAMMPS.
The system I am trying to simulate has a mix of sp2 and sp3 bonds (all carbon). The temperature shoots up almost immediately after start ( NVT or NVE ensemble). The code complains of lost atoms. I have tried many different things including, reducing the timestep and minimizing the structure before running MD.

I also did the following checks:

  • MD runs on purely sp3 system (diamond) using AIREBO in lammps: runs just fine - sanity check for my lammps input parameters.

  • I have run the mixed sp2/sp3 system above with no problem using the original brenner code - hence it appears to me that the initial geometry is ok.

I would greatly appreciate any insight from the lammps community.

Best
-Shashi

shashi,

it is very likely that you are still making a mistake somewhere.
please produce a minimal input that reproduces your problem
and post it to the list and people will be able to comment.

whether your geometry works with some other code is of little
relevance, since there are so many other possibilities for mistakes.

without a simple way to reproduce your issues, one would have
to speculate and thus i doubt that anybody will be able to make
any useful comments.

cheers,
   axel.

If you can create an initial geometry and dump energy/forces from
both codes and show that they are the same or different (all sp3 vs
mixed system), that would be helpful. Then someone like Ase (the
author of AIREBO in LAMMPS) could do some debugging.

Steve