A many-body interatomic potential for Pd within the second-moment approximation of the tight-binding model was used by fitting to the volume dependence of the total energy of the metal, computed by first-principles linearized augmented plane wave calculations. This potential achieved good accuracy for the elastic constants, phonon spectrum, along with the temperature dependence of the lattice constant of Pd. This was also used, in tandem with molecular-dynamics simulation, to study the self-diffusion of single adatoms on the Pd(111) surface. The diffusion coefficient of Pd adatoms was computed, and was found to exhibit Arrhenius behavior. The migration energy and pre-exponential factor for the hopping mechanism were determined and compared with scanning tunnelling microscopy measurements and previous calculations. The computed values were generally in better agreement with experimental data, than were those of previous computational work.

Interatomic Potential for Pd and Molecular-Dynamics Simulation of Diffusion in Pd/Pd(111) System. Papanicolaou, N.I., Papaconstantopoulos, D.A.: Thin Solid Films, 2003, 428[1-2], 40-6