Parametrization of modified embedded-atom-method potentials for Ph, Pd, Ir, and Pt based on density functional theory calculations, with applications to surface properties

A scheme to obtain modified embedded-atom-method (MEAM) potentials from density functional theory calculations for fee metals has been developed. This scheme is applied to the platinum-group metals Rh, Pd, Ir, and Pt. Bulk and surface properties, including surface reconstructions and self-diffusion barriers, are calculated with these MEAM potentials and are compared with available experimental data. The potentials are able to predict the (100)-(1 x 5) hexagonal and (110)-(1 x 2) missing row surface reconstructions of Ir and Pt as well as their absence on Rh and Pd. Also, the physical interpretation of the MEAM and related models is addressed, linking it to the bond-order conservation principle. With the help of the latter, it is shown that the MEAM has a solid theoretical base and is able to give straightforward relations between such properties as the vacancy formation energy and the occurrence of the (1 x 5) surface reconstruction on the (100) surface.