Universal Relation between the Kolmogorov-Sinai Entropy and the Thermodynamical Entropy in Simple Liquids

We report computation of the Kolmogorov-Sinai entropy in a variety of simple liquids studied by molecular dynamics. It is found that this quantity, when expressed in terms of the atomic collision frequency, is uniquely related to the thermodynamic excess entropy by a universal linear scaling law. We also present a simple probabilistic model for relaxation in condensed atomic systems in which the observed scaling relation arises naturally.