Calculations of Chemical Shifts of X-ray Emission Spectra and Effective States of Nb Atom in the Niobates

Abstract

A computational approach to evaluation of chemical shifts of characteristic X-ray emission lines of d and f elements in different chemical compounds is proposed. It is based on modeling the embedded cluster electronic structure using relativistic pseudopotential approximation that is followed by restoration of (all-electron) wavefunction in the core region. The proposed approach is applied to the Nb Kα lines in fersmite. The line positions and their shifts with respect to those of metallic Nb were evaluated via the restoration of the all-electron wavefunction in the Nb core region. The results are in satisfactory agreement with the experiment, overestimating the measured value by ∼20 %.