An n-body potential was developed and satisfactorily applied to hexagonal close-packed metals, Co, Hf, Mg, Re, Ti and Zr, in the form of long-range empirical potential. The potential could well reproduce the lattice constants, c/a ratios, cohesive energies, and the bulk modulus for their stable structures (hexagonal close-packed) and metastable structures (body-centered cubic or face-centered cubic). Meanwhile, the potential could correctly predict the order of structural stability and distinguish the energy differences between their stable hexagonal close-packed structure and other structures. The energies and forces derived by the potential could smoothly go to zero at cut-off radius, thus completely avoiding the unphysical behaviours in the simulations. The developed potential was applied to study the vacancy, surface fault, stacking fault and self-interstitial atom in the hexagonal close-packed metals. The calculated formation energies of vacancy and divacancy and activation energies of self-diffusion by vacancies were in good agreement with the values in experiments and in other works. The calculated surface energies and stacking fault energies were also consistent with the experimental data and those obtained in other theoretical works. The calculated formation energies generally agree with the results in other works, although the stable configurations of self-interstitial atoms predicted in this work somewhat contrast with those predicted by other methods. The proposed potential was shown to be relevant for describing the interaction of body-centered cubic, face-centered cubic and hexagonal close-packed metal systems, bringing great convenience for researchers in constructing potentials for metal systems constituted by any combination of body-centered cubic, face-centered cubic and hexagonal close-packed metals.

Long-Range Empirical Potential Model - Extension to Hexagonal Close-Packed Metals. Y.Dai, J.H.Li, B.X.Liu: Journal of Physics - Condensed Matter, 2009, 21[38], 385402