ELECTRONIC-STRUCTURE AND VIBRATIONAL PROPERTIES IN DISORDERED MATERIALS

Selfconsistent band structure methods based on the LMTO method are dev eloped and applied for calculations of free energy properties of struc turally disordered materials. We study temperature variations of phono n related properties in some 3d, 4d and 5d metals of different structu re, by the average scattering method, within the quasi-harmonic approx imation. As shown earlier for 4d metals [4], the effect of vibrations on the electronic structure is well described by the average scatterin g around one single atom. Results for phonon moments and some temperat ure dependent properties like phase stability are presented for severa l metals showing polymorphism with temperature and at ordinary pressur e. The role of electronic free energies for stabilizing the high tempe rature bcc phase in Ti and Zr metals and related alloys is analysed.