Graphene-C60 interaction without Brenner potential

Hi all !

I have been trying to model a C60 particle on a graphene sheet. The intra-atomic interaction between C60 atoms and graphene atoms are modeled via REBO potential. The interaction between C60 and graphene should be via only LJ potential.

Let say C60 atoms are of type 1 and graphene atoms are of type 2.

pair_style hybrid/overlay lj/cut 10.0 rebo
pair_coeff 1 1 lj/cut 0.0 0.0
pair_coeff 2 2 lj/cut 0.0 0.0
pair_coeff 1 2 lj/cut 0.0684 3.4
pair_coeff * * rebo inputfiles/CH.airebo.real C C

In the above model, C60 and graphene atoms interact via REBO potential also along with LJ. How do I avoid the REBO potential for these cross interactions (between C60 and graphene) ?

Thank you in advance.


You can do this by using redo twice in your pair_style hybrid command.
Then the coeff commands apply the first rebo to * * … C NULL
and the second rebo to * * … NULL C.
Then the 1 2 interaction is lj/cut. There is an example
for this using tersoff instead of redo, on the pair hybrid doc page.

Note that in a real system it’s just each C atom with some surrounding
C atoms. They don’t “know” some are in the sheet and some in the buckyball.
So you should ask shy REBO for everything isn’t a better model.