Mapping a potential to polymorphic pair_style (or any other alternative?)

LAMMPS LAMMPS General Discussion
1

I want to simulate the potential described in this paper (Eqs. 2.1 - 2.3) in LAMMPS.

For the sake of convenience, the equations are:

screenshot-2024.10.12_17.31.42

image

Eq. 2.1 is a pairwise interaction while the Eq. 2.2 is a three-body term with k_ij (k_ik) given by Eq. 2.3.

I could not see a way to simulate such a potential in LAMMPS unless through the polymorphic pair_style. This is what I have tried so far.

The problem is: my simulations (through polymorphic) do not fully agree with the original paper, which may be caused by a series of factors. Most probably a bad conversion into the LAMMPS polymorphic form by me.

Now my two questions are:

  1. Is there an alternative approach to simulating this potential in LAMMPS?
  2. Any polymorphic-experienced user could take a look in my equations just to check for any obvious mistakes?

Thanks to you all in advance.