Binding Surfaces and Structural Phase Transformations

We have calculated binding surfaces for cla changes (along the Bain path) and changes of the atomic volume of metallic systems undergoing martensitic transformations. We find characteristic differences between the surfaces of nonmagnetic systems (with a close packed low temperature structure) and magnetic systems (with a less close packed low temperature structure). The ab initio calculations have been performed by using the augmentedspherical-wave method within the local-density approximation in the case of stoichiometrically ordered compounds and the Korringa-Kohn-Rostocker method together with the coherent-potential approximation in the case of disordered alloys.