This award will support collaborative research in metallurgy between Dr. Didier de Fontaine, University of California at Berkeley and Dr. H. Dreysse, Laboratoire de Physique du Solide, University of Haute Alsace, Mulhouse, France. This project concerns the theoretical study of phase quilibrium in metal, semiconductor or superconducting alloys, including studies of surfaces and interfaces. Electronic band structure calculations have progressed to the point where quantitative prediction can be made concerning the stability of various competing phases in metals, alloys and simple compounds. Statistical thermodynamical methods have also been developed so that, by combining both quantum and statistical techniques, certain classes of alloy phase diagrams can now be derived almost from first principles. The purpose of the proposed collaborative research is to combine the expertise of both the Mulhouse and Berkeley groups to perform such combined quantum/statistical calculations by means of methods which have been developed by the two groups independently. The Berkeley group has gained considerable expertise in the theoretical study of alloy phase diagrams by the Cluster Variation method; the Mulhouse group has specialized in the electronic structure of solids. The results of this research will contribute to the understanding of predictive thermodynamics of materials.