Density Functional Approach to the Surface Tension of Liquid Metals

The local density functional formalism of Evans and Hasegawa, previously developed for the study of surface properties, is re‐examined by including nonlocality of pseudopotential in the theory. It is found that (i) when the pseudopotential is nonlocal, the fourth order density gradient correction of Ma and Sahni must be included in order that the density profiles obtained are physically meaningful and (ii) the first order perturbation is inadequate for understanding the surface tension of simple liquid metalsin accordance with conclusions made by other investigators.