The simplest possible model for diffusion in an amorphous metal was studied. This consisted of a linear chain, with randomly distributed site and saddle energies. Linear chains which contained 1000, 2000 or 4000 sites were investigated, and the particle energies at site points could take only 2 possible values. This was also true of the saddle points. There were also 2 possible distances between adjacent sites. An improved calculation scheme led to the precise relationship between the mean square displacement and the number of jumps for a given diffusion time.

Computer Simulation of Diffusion in Disordered Systems. P.K.Hung, V.V.Hoang, T.D.Hanh, P.N.Nguyen: Materials Science Forum, 1999, 312-314, 443-8