How to do it - Core/shell model

Hello all,

I am trying to implement a basic core/shell model potential in lammps, with a harmonic spring potential for the interaction between core and it’s corresponding shell, short range interactions between the shells using Buckingham potential, the long range interactions with the coul/wolf summation and a optional 3 body bond bending term.

I tried to validate the potential by fitting the parameters of THB1 potential of Olivine crystal from Lattice dynamics of Forsterite(G D Price et al 1987), when I tried to minimize the crystal, I always find the pressure of the system is very high(i.e., to the order of eg 2797073.6), I am using metal units. Am I missing something to check.

Is there any standard procedure in Lammps to validate a new potential.

Thanks in advance,

Best Regards,

Srinivasan Mahendran,

Wissenschaftliche Mitarbeiter,

TU Bergakademie Freiberg

The way I would do this is run for 0 steps for
a snapshot of atoms where you know the
answer. If you get the energy and forces
right, then the pressure should be right.