Evaluation of phenomenological one-phase criteria for the melting and freezing of softly repulsive particles

TL;DR

This study evaluates the effectiveness of phenomenological one-phase criteria in predicting melting and freezing points across various particle interaction models, finding generally reliable estimates especially for FCC solids.

Contribution

It systematically tests and validates phenomenological criteria against phase diagrams for different soft particle potentials, highlighting their reliability and limitations.

Findings

One-phase rules reliably estimate transition points.

Better agreement for FCC than BCC solids.

Re-entrant transitions affect the accuracy of criteria.

Abstract

We test the validity of some widely used phenomenological criteria for the localization of the fluid-solid transition thresholds against the phase diagrams of particles interacting through the exp-6, inverse-power-law, and Gaussian potentials. We find that one-phase rules give, on the whole, reliable estimates of freezing/melting points. The agreement is ordinarily better for a face-centered-cubic solid than for a body-centered-cubic crystal, even more so in the presence of a pressure-driven re-entrant transition of the solid into a denser fluid phase, as found in the Gaussian-core model.