Universal scaling of pair-excess entropy and diffusion in Yukawa liquids

Abstract

Understanding diffusion in liquids from properties of static structure is a long standing problem in condensed matter theory. Here, we report an atomistic study of excess entropy and diffusion coefficient in a strongly coupled Yukawa liquid. We observe that the pair excess entropy s2 scales with temperature as −3.285 (Tm/T)0.665 and contributes to about 90% of the total excess entropy close to the freezing transition Tm. We further report that at low temperatures where the diffusive transport is mediated by cage relaxation, the diffusion coefficient when expressed in natural units of the Enskog collision frequency and the effective hard sphere diameter, obeys the scaling law 0.04 es2 and deviates from it at high enough temperatures where cages cannot form.