Dear Dr.axel


I calculate total energy of (polyethylene+cnt) that is about -40000 kcal/mol. but when i calculate total energy of polyethylene and CNT, I see these are respectively, -35000 and -5000 kcal/mol. thus, E polyethylene + E cnt - E toatal =0. but I thunk that it must be non-zero because the interaction energy should be considered in both cases. How does LAMMPS distribute the interactions between graphene and polyethylene?

best wishes

I think you are asking how compute pe/atom compares to compute pe. The sum of the former
over all the atoms (of both constituents in your case) should equal the latter. So for
the PE of a CNT atom, LAMMPS does include the interactions with both other CNT atoms
and polyethylene atoms.

You could use the rerun command on a dump snapshot(s) of your system
and define a pair hybrid command with no interactions between the

two components. Then the pe/atom sum over either constituemt will
not include cross interactions.