[lammps-users] How to calculate the force interaction between two groups of atoms in AIREBO potential


I am using AIREBO potential to simulate graphene tensile test by displacement loading and want to trace the tension.

The graphene is divided into three groups: ‘left’, ‘mobile’ and ‘right’. The atoms of ‘left’ and ‘right’ is moved to realize displacement loading by the commond fix setforce 0.0 and displace_atoms.

I tried to use compute group/group to calculate the force interaction between ‘mobile’ and other one as tension. However, the pair style AIREBO does not support compute group/group.

I would like to know if it is possible to calculate the force interaction in AIREBO potential and how to accomplish this?

Thank you very much for your answer.

Wenpeng Zhu


No, you can't. For many-body potentials like AIREBO,
it's not even clear what a group-group energy/force means.
Since there are up to 6 atoms interacting together to
generate energy/force in small clusters, which of the 2
groups would those 6 atoms need to be in to be
considered a group/group interaction, and how would
the energy/force be allocated between the 2 groups?

Even if you can figure out the answer to that question,
LAMMPS does not do that kind of bookkeeping when
it computes AIREBO forces.


2010/1/5 Wenpeng Zhu <[email protected]>: