It was shown, by using molecular dynamics simulations, that correlated processes which involved both jumps and exchanges became important in the diffusion of Ag on the (110) surface at temperatures of about 600K. The Ag was modelled by using many-body potentials that were derived within the framework of the tight-binding model. It was shown that the high-temperature diffusion could proceed via many different elementary mechanisms. Single and long jumps along the [100] direction, and simple exchanges, were common at the lowest temperature (450K) which was considered. Thus, simple exchanges were possible along the [001] direction and in the diagonal direction; with essentially the same probability. Correlated events that involved exchanges became important as the temperature was increased to 600K. These events could be of jump-exchange, exchange-jump, or exchange-exchange types. They could be even more complicated and, at temperatures above 600K, they made up some 25% of the total exchanges.

R.Ferrando: Physical Review Letters, 1996, 76[22], 4195-8