Ab initio calculations of entropies of liquid alloys

Abstract

The Gibbs‐Bogoliubov method with a hard-sphere reference system allows direct calculation of entropies of metals and alloys. Necessary input-information, however, are the pseudopotentials and the mean volumes per atom. Also, to ensure the validity of pseudopotential perturbation theory, the valence differences of the constituentions in any system should be small.

We have studied all simple (pseudopotential) binary alloys of which we are aware, where the valence difference is zero or unity, for which the volumes are known and for which entropy data are available. It is possible to assign a single empty core pseudopotential to each ion (usually corresponding quite closely to that obtained by fitting electrical resistivity and Fermi surface data) so as to give a rather convincing comparison between the calculated and observed entropies both for the pure liquids and the alloys.