Surface properties of liquid mercury: a comparison of density-dependent and density-independent force fields

TL;DR

This study compares different atomistic force fields for liquid mercury to evaluate their accuracy in predicting surface tension and coexistence properties, optimizing models for better experimental agreement.

Contribution

It introduces an optimized density-independent force field for liquid mercury that improves surface tension predictions compared to existing models.

Findings

Density-independent model achieves higher surface tension values.

Optimized model shows better agreement with experimental data.

Monte Carlo and semi-analytic methods support the simulation results.

Abstract

Motivated by an experimental interest we investigate by the means of atomistic Molecular Dynamics simulation the ability of density-independent, empiric density-dependent, and recently proposed embedded-atom force fields for liquid mercury to predict the surface tension of the free surface of liquid mercury at the temperature of 293~K. The effect of the density dependence of the studied models on the liquid-vapor coexistence and surface tension is discussed in detail. In view of computational efficiency of the density-independent model we optimize its functional form to obtain higher surface tension values in order to improve agreement with experiment. The results are also corroborated by Monte Carlo simulations and semi-analytic estimations of the liquid-vapor coexistence density.