MSXα calculations of octahedral clusters in titanium and vanadium oxides

Abstract

Using the spin-polarized MSXα method in the muffin-tin approximation, calculations of the electronic structure of VO 10− 6 and TiO 10− 6 clusters in vanadium and titanium monoxides have been carried out. The effects of exchange polarization in these compounds are studied and appear to be quite small, the largest energy difference between corresponding α and β spin-orbitals not exceeding 1 eV for VO 10− 6 and 0.8 eV for TiO 10− 6. The molecular orbital diagrams calculated are compared with the full sets of X-ray emission spectra of the compounds and an interpretation of experimental spectra bands is given. A comparison between the MSXα and semiempirical MO LCAO results shows reasonable agreement. The stabilization of energy levels of VO 10− 6 and TiO 10− 6 clusters in the crystal lattice of oxides with higher oxidation number of metal is studied. The results of these calculations are in good agreement with the experiments and demonstrate the applicability of cluster MSXα methods for the study of electronic structure not only for dielectrics but also for compounds possessing metallic conductivity such as the vanadium and titanium monoxides.