[lammps-users] interatomic potentials for BCC

Hello everyone,

I would like simulate BCC materials. Is there a recommended interatomic potential for these materials?

Jaime Sanchez

One potential which works is the Yukawa potential exp(-Kr)/r, where K is
an inverse screening length. It is sometimes fcc-stable and
sometimes bcc-stable: the latter is generally at higher T and lower K. I
can send you some papers with phase diagrams if you like.

Another potential with similar phase-behavior (sometimes fcc-stable,
sometimes bcc-stable) is the inverse-power potential r^-n. A third is
the soft-core Gaussian potential exp(-r^2/a^2).

I think the Morse potential may also be bcc-stable for certain values of
the parameters.

In general, potentials with long tails favor bcc, while potentials which
are more hard-sphere-like favor fcc. For example, the stable lattice for
a Coulomb crystal is bcc.