Modified analytical embedded-atom method many-body potentials were constructed for hexagonal close-packed metals. The potentials were parametrized by using analytical functions, and were fitted to the cohesive energy, the unrelaxed vacancy formation energy and 5 independent second-order elastic constants. Each of the constructed potentials represented a stable hexagonal close-packed lattice having a particular non-ideal c/a ratio. In order to treat metals with a negative Cauchy pressure, a term was added to the total energy. For all of the metals considered (Be, Co, Hf, Mg, Re, Ru, Sc, Ti, Y, Zr), the hexagonal close-packed lattice was energetically the most stable when compared with the face-centered cubic and body-centered cubic structures, or with an hexagonal close-packed lattice having the ideal c/a ratio. The activation energy for vacancy diffusion in the metals was calculated. This agreed well with available experimental data. The most likely diffusion paths were predicted. The stacking-fault and surface energies were also calculated, and their values were lower than typical experimental values. The self-interstitial atom formation energy and volume were evaluated for 8 possible sites. These results suggested that the basal split or crowdion was the most stable configuration for metals having a relatively large deviation from the ideal c/a value. The non-basal dumb-bell was the most stable configuration for metals with a c/a ratio which was near to the ideal value. The relationship between the self-interstitial atom formation energy and the melting point was roughly linear relation, except in the case of Ru and Re.

Analytic Modified Embedded Atom Potentials for HCP Metals. W.Hu, B.Zhang, B.Huang, F.Gao, D.J.Bacon: Journal of Physics - Condensed Matter, 2001, 13[6], 1193-213