Hi everyone,
I'm having a question about the implementation of MEAM potentials
in LAMMPS. Looking at the documentation and the potential parameter files
(i.e., library.meam) the implemented parametrization is that of Baskes, PRB 46, 2727 (1992).
But if I look at some more recent potentials, i.e., the ones for Ga and Pu and Lee's 2N MEAM potentials
for bcc metals, the parametrization appears to be different. One apparent difference is the functional
form for Rose's universal equation of state. In Baskes' 1992 paper, the used functional form is
E^u=-E_i(1+a^*)exp(-a*).
In Baskes's 2002 PRB paper for the MEAM potential for Ga, it reads
E^u=-E_i(1+a^*+r_e/R*delta*(a^*)^3)exp(-a*),
which includes a cubic term in a^* and the additional fittable parameter "delta". The same
kind of parametrization also appears in Lee, Baskes et al, second-nearest neighbor MEAM potential
for bcc transition metals (PRB 64, 184102, (2001).
Is there an easy way to add these MEAM potentials to LAMMPS, or would it require
additional programming?
Thanks,
Maurice