Excess entropy, Diffusivity and Structural Order in liquids with water-like anomalies

TL;DR

This paper demonstrates that excess entropy is a key factor linking structural, diffusional, and density anomalies in water-like liquids, supported by simulations of silica and ramp liquids.

Contribution

It reveals the role of excess entropy in explaining water-like anomalies and introduces a pair correlation approximation to understand this relationship.

Findings

Water-like anomalies are connected to non-monotonic density dependence of Se.

Simulations show Se correlates with structural and diffusional anomalies.

Pair correlation approximation helps explain the link between entropy and structural order.

Abstract

The excess entropy, Se, defined as the difference between the entropies of the liquid and the ideal gas under identical density and temperature conditions, is shown to be the critical quantity connecting the structural, diffusional and density anomalies in water-like liquids. Based on simulations of silica and the two-scale ramp liquids, water-like density and diffusional anomalies can be seen as consequences of a characteristic non-monotonic density dependence of Se. The relationship between excess entropy, the order metrics and the structural anomaly can be understood using a pair correlation approximation to Se.