Liquid–vapour interface of simple fluids interacting by the modified Morse potential

Abstract

The liquid–vapour diagram and the surface tension of simple fluids were calculated by means of molecular dynamics. The Morse function is modified including an extra adjustment parameter and this new function is the interaction law among the particles. This same function was already employed for estimating transport properties of liquid alkali metals near the melting point [F. Juan-Coloa et al. Mol. Sim. 33 (2007), pp. 1167–1172]. The surface tension and the orthobaric densities related to this kind of fluid are shown for the first time in this work. These same quantities are calculated for three cut-off radii , and . As a relevant result, we found that the complete interaction is estimated using a cut-off distance of . Furthermore, it is verified whether both Morse and modified Morse potentials follow the law of the corresponding state.