Entropies and structure factors of liquid metals

Abstract

Recent theory, relating the thermodynamics for a real liquid to that of a hard sphere reference system suggests a correlation between the entropy and the structure factor. The extent to which this correlation exists in liquid metals is investigated by comparing, for each system and at various temperatures, the packing fractions deduced respectively from entropy and structure factor measurements. The quality of agreement is, overall, comparable with that obtained from previous comparisons of measured and hard sphere structure factors as functions of wave number. The standard ab initio method of calculating interatomic forces in simple metals uses pseudopotential theory. It is suggested that near the melting points entropies for all valencies, and specific heats for lower (<or=3) valencies, are adequately described by the usual pseudopotential techniques.