A new analytical surface energy model for arbitrary (h k l) planes in BCC and FCC metals

Abstract

A new analytical surface energy model (Eq. 9) that is free of adjustable parameters has been developed to accurately predict the surface energies of arbitrary (h k l) planes in both BCC and FCC ground-state pure metals at 0 K, using only (100), (110) and (111) surface energies as input. The formulation is established by expanding the original broken-bond model up to the 3rd nearest neighbor shell and considering the surface relaxation effect. In addition, this model consists of only one single formula per crystal structure, overcoming the geometric complexities in previous models in which multiple equations are needed for different surface groups. The analytical model has been validated through the comparison with 4357 independent surface energies. These data include the energies of 517 unique surfaces per metal in Fe, Cr, W, Cu, Ni, and Al (a total of 3102 surface energies) that are calculated through our molecular dynamics simulations, and excellent agreement is obtained. The validation data also include 1255 independent surface energies in literature or online database for up to 46 BCC and FCC metals that were calculated by either empirical potentials or density functional theory. The agreement is still very good for most of the data, demonstrating the robustness of our new model.