Sound velocities of Lennard-Jones systems near the liquid-solid phase transition

TL;DR

This paper calculates sound velocities in Lennard-Jones systems near the liquid-solid transition, showing good agreement with theoretical values and discussing implications for melting and diffusion relations.

Contribution

It introduces a method to compute sound velocities at phase coexistence using the additivity principle, linking them to thermodynamic properties.

Findings

Sound velocities agree with exact thermodynamic relations.

Results support Lindemann's melting rule.

Comparison with experimental argon data is favorable.

Abstract

Longitudinal and transverse sound velocities of Lennard-Jones systems are calculated at the liquid-solid coexistence using the additivity principle. The results are shown to agree well with the ``exact'' values obtained from their relations to excess energy and pressure. Some consequences, in particular, in the context of the Lindemann's melting rule and Stokes-Einstein relation between the self-diffusion and viscosity coefficients are discussed. Comparison with available experimental data on the sound velocities of solid argon at melting conditions is provided.