Comparison of the structures of the liquid-vapor interfaces of Al, Ga, In, and Tl

Abstract

We report the results of self-consistent quantum Monte Carlo simulations of the liquid-vapor interfaces of the members of the family of trivalent metals Al, Ga, In, and Tl. In each case the single particle density distribution along the normal to the liquid-vapor interface is stratified and the pair correlation function in the plane of the interface is essentially the same as that in the bulk liquid. We have examined the results of the calculations for structural similarities that hint at the existence of a corresponding states representation valid for a family of metals, such as has been shown for the family of alkali metals. The effective pair potentials of Al, Ga, In, and Tl are rather different from each other. Consequently, characterization of the interface structure using a corresponding states representation in two variables (reduced density and reduced diameter) is not accurate, unlike the case of the alkali metals for which such a characterization is accurate. Experimental data concerning the structure of the liquid-vapor interface exist for only one member of this family of metals, namely Ga. Good agreement between theory and experiment in that case argues for the validity of the results reported for all of the metals of this family, and the inferences drawn therefrom.