A self-consistent theory of single-particle motion in ordinary and supercooled liquids

Abstract
The mean square displacement of a tagged particle in a liquid is known to exhibit a diffusive linear time dependence beyond a microscopic timescale. By making use of simple mode-coupling concepts the authors derive a set of analytic self-consistent equations for the relevant dynamical quantities in this regime, namely the diffusion coefficient and the intercept. The results of the theory are successfully compared with the data obtained by simulation experiments in different systems.