Non-stochastic behavior of atomic surface diffusion on Cu(111) at all   temperatures
  Atomic diffusion is usually understood as a succession of random, independent displacements of an adatom over the surface's potential energy landscape. Nevertheless, an analysis of Molecular Dynamics simulations of self-diffusion on Cu(111) demonstrates 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. 
J. Ferr\'on, L. G\'omez, J.J. de Miguel and R. Miranda