Eur. Phys. J. B (2015) 88: 323
https://doi.org/10.1140/epjb/e2015-60594-2

Regular Article

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

¹ Institut für Theoretische Physik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
² Department of Materials Science & Engineering, University of Utah, 122 South Central Campus Dr., Salt Lake City, 84112, Utah, USA

^a e-mail: iakovlev@theorie.physik.uni-goettingen.de

Received: 22 July 2015
Received in final form: 6 October 2015
Published online: 7 December 2015

Abstract

Motivated by growing interest in interfacial properties of liquid mercury we investigate by atomistic Molecular Dynamics simulation the ability of density-independent, empiric density-dependent, and recently proposed embedded-atom force fields to predict the surface tension and coexistence density of liquid mercury at room temperature, 293 K. The effect of the density dependence of the studied models on the liquid-vapor coexistence and surface tension is discussed in detail and our results are corroborated by Monte Carlo simulations and semi-analytic liquid-state theory. The latter approach is particularly useful to identify and rationalize artifacts that arise from an ad-hoc generalization of density-independent potentials by introducing density-dependent coefficients. In view of computational efficiency and thermodynamic robustness of density-independent model we optimize its functional form to obtain higher surface tension values in order to improve agreement with experiment.