Embedded-atom-method interatomic potentials for hcp metals

We develop here an empirical procedure for constructing embedded-atom-method (EAM) interatomic potentials for hcp metals. This is based on fitting perfect-crystal lattice properties. The contribution of the lattice inner degrees of freedom, due to the two atoms per lattice site, is included into the elastic response of the crystal. It is found that the elastic constants of several hcp pure metals cannot be fitted within the EAM. For example, no valid potential can be constructed for Cd, Zn, Be, and Y, which properly adjust the measured elastic constants. Neither could we find an appropriate fit for Zr.