Nature of the entropy versus self-diffusivity plot for simple liquids

Abstract

The empirical relation (D^∗)α = a exp[S] between the self-diffusion coefficient D^∗ and the excess entropy S of a liquid is studied here in the context of theoretical model calculation. The coefficient α is dependent on the interaction potential and shows a crossover at an intermediate density, where cooperative dynamics become more important. Around this density a departure from the Stokes-Einstein relation is also observed. The above relation between entropy and diffusion is also tested for the scaled total diffusion coefficient in a binary mixture.