Breakdown of The Excess Entropy Scaling for the Systems with Thermodynamic Anomalies

TL;DR

This study investigates the limitations of Rosenfeld entropy scaling in systems with thermodynamic anomalies, showing it only applies under specific conditions and not within anomalous regimes.

Contribution

It demonstrates the breakdown of Rosenfeld entropy scaling in systems with thermodynamic anomalies, highlighting its validity only at high temperatures or outside anomaly ranges.

Findings

Rosenfeld scaling valid only at infinite temperature for Herzian spheres and Gauss Core Model.

Scaling valid at low temperatures for soft repulsive shoulder but outside anomaly range.

Scaling formula fails within the diffusion anomaly region for studied systems.

Abstract

This articles presents a simulation study of the applicability of the Rosenfeld entropy scaling to the systems which can not be approximated by effective hard spheres. Three systems are studied: Herzian spheres, Gauss Core Model and soft repulsive shoulder potential. These systems demonstrate the diffusion anomalies at low temperatures: the diffusion increases with increasing density or pressure. It is shown that for the first two systems which belong to the class of bounded potentials the Rosenfeld scaling formula is valid only in the infinite temperature limit where there are no anomalies. For the soft repulsive shoulder the scaling formula is valid already at sufficiently low temperatures, however, out of the anomaly range.