Theory of the surface tension of liquid metals

The authors present the theory of a method for calculating the surface tension gamma of liquid simple metals. The method uses the direct perturbation expansion to second order of the electron-ion pseudopotential. It is found that the second order correction to gamma is significant for liquid metals and that certain important pseudo-atom models which have previously been proposed (Evans and Kumaravadivel (1976), Mon and Stroud (1980)) are inadequate, at least in principle, from a microscopic point of view. The calculated values of gamma for Na and Al are in good agreement with experiment.