Systematic Aspects of The Electronic Structure of 3d Transition-Metal Compounds

Systematic changes in the electronic structure of 3d transition-metal compounds with varying chemical compositions are studied by photoemission spectroscopy and configuration-interaction cluster-model analysis. The changes consist of(I) the smooth variation of model parameters such as the charge-transfer energy Δ and the d-d Coulomb repulsion energyU with atomic number and valence and (II) the apparently irregular multiplet corrections to Δ and U, which are functionsof the nominal electron number. These systematics are reflected upon the band gaps, covalency and character of dopedcarriers in transition-metal oxides and chalcogenides, and upon the optical absorption spectra and the ionization energies of substitutional transition-metal impurities in semiconductors.