What is the syntax to use two different potentials in a single simulation? {MEAM & Tersoff}

I am doing a diffusion between Fe and Diamond (C)

Fe-Fe (interaction)–> MEAM potential
Fe-C (Interaction)–> MEAM potential
C-C (interaction) → Tersoff potential

The potential files are as follows
C.tersoff
library.meam
FeC.meam

I think pair_style hybrid can be used here.
Note I want to avoid lammps from taking C-C interaction as MEAM when I use meam potential file and want to avoid Fe-C or Fe-Fe interaction when I use tersoff file.

I read the documentation and have used the understatement to exclude aout atomic pairs but cant get the syntax right.
a) pair_coeff 1 2 none
b) neigh_modify exclude type 1 2

Document link
https://docs.lammps.org/pair_hybrid.html

Can anyone show me the syntax for this?

No, this cannot be done with pair style hybrid since neither potential is pairwise additive, which would be required for the mixed term.

The best choice is to use MEAM for all. Despite the syntax requirements, using Tersoff for C-C interactions would remove the carbon contributions to the embedding term and thus also taint the accuracy of the MEAM forces.

Thank you for the response.
Actually had seen the usage of these two potential in a paper.
In this MEAM potential can I exclude C-C interaction?

If yes than how?

I had tried pair_coeff 1 * for MEAM but it gave a syntax error

The authors of that paper must have modified the LAMMPS source code or the potential parameters or both. Or use a Lennard-Jones or Morse potential for the mixed term. Bypassing the syntax requirements, doesn’t make this a good model, specifically for the purpose you are describing. If I would review a paper using such a model, I would reject it for using a bogus combination of potential interactions.

A lot of things get published, not all of them are good ideas.

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