An analysis of molecular dynamics simulations of self-diffusion on Cu(111) demonstrated the existence of different types of correlations in the atomic jumps at all temperatures. Thus, the atomic displacements cannot be correctly described in terms of a random walk model. This fact has a profound impact on the determination and interpretation of diffusion coefficients and activation barriers.

Nonstochastic Behavior of Atomic Surface Diffusion on Cu(111) Down to Low Temperatures. J.Ferrón, L.Gómez, J.J.de Miguel, R.Miranda: Physical Review Letters, 2004, 93[16], 166107 (3pp)