It was noted that evidence from molecular dynamics simulations indicated that a universal relationship existed between the structure and the equilibrium rate of atomic diffusion in liquids and solids. It was found that the diffusion coefficient, when reduced to a dimension-less form by scaling with the atomic collision frequency and the atomic diameter, was uniquely defined by the excess entropy. The latter was a measure of the number of accessible configurations of the system. A scaling law which correlated these 2 quantities held well for simple liquids, and was also applicable to atomic transport in a quasicrystal and to Ag-ion diffusion in -AgI. This made it possible to estimate diffusion coefficients directly from diffraction measurements of the radial distribution function for the diffusing species.

M.Dzugutov: Nature, 1996, 381[6578], 137-9