A molecular dynamics simulation of Au diffusion on Au(111) and of Ag diffusion on Ag(111) was carried out for a wide range of temperatures; which reached up to an homologous temperature of 0.5. The Au and Ag were modelled by using many-body potentials that were derived from the second-moment approximation to the tight-binding model. The potential energy barriers (zero temperature) for diffusion were calculated by permitting full relaxation of the crystal. The resultant barriers tended to be rather low for metals. However, within the temperature range considered, the activation energies were not significantly different from the potential energy barriers at 0K.

R.Ferrando, G.Tréglia: Surface Science, 1995, 331-333, 920-4