Cluster Models for Electronic Structure of Oxide Ceramics

Recent progress in using cluster models to calculate electronic structure of oxide ceramics such as transition‐metal monoxides, zirconia, α‐alumina, ruby, and copper‐based superconducting oxides is reviewed. The self‐consistent field local density theory is used to find potentials, energy levels, and wave functions for a fragment consisting of N atoms embedded in the infinite solid. The single‐particle spectra are compared with photoelectron and optical data, and with X‐ray absorption and emission. Total energy calculations provide cohesive energies for prediction of relative stability of defect structures and lattice relaxation in the vicinity of impurities. A brief description is given of surface‐structure calculations for an α‐alumina (0001) surface.