Simple analytic embedded atom potentials for HCP metals

A new simple analytic embedded atom model including a modified term, which has previously been successfully applied to the atoms in the fcc and bcc crystal systems, is now extended to the HCP structure. The model parameters are determined for HCP transition metals Co, Hf, Re, Ru, Sc, Ti, Y and Zr with ideal c/a ratios. The model is fitted to the lattice constants, cohesive energy, vacancy formation energy, elastic constants and is able to reproduce the experimental data quite well. The structure stability of real HCP, bcc and simple cubic is discussed, the formation energy of divacancy in the base plane and in different planes are also calculated, and the divacancy is found to be not bound.