I have a question about EAM-type potentials that can be used with LAMMPS.
A pair potential function f(r) is tabulated in the DYNAMO86 format as
sqrt(r*f(r)), i.e. as an effective charge (and only in this way to my
knowledge). This fact restricts f(r) to be always a non-negative function.
Nowadays it is not the case for many EAM-type potentials.
An obvious solution might be to make use of the EAM potential transformation
like f(r) -> f(r)+2g*rho(r) in order to remove negative values from f(r).
However there exist EAM models that have charge density rho(r)=0 in the range
where f(r)<0. And this method fails. I wonder if such potentials can be used
with LAMMPS? Or it is necessary to modify its source code?