Investigation of the vanadium L23-edge x-ray absorption spectrum of SrVO3 using configuration interaction calculations: Multiplet, valence, and crystal-field effects

Configuration interaction cluster calculations have been performed to investigate the electronic structure of orthorhombic distorted SrVO3 compound, where a considerable tetragonal crystal-field splitting of larger than 180 meV for t(2g) orbital levels is suggested for the good consistence between the simulated and the experimental spectral line shape. This supports the crystal-field splitting scenario for the metal-insulator transition mechanism. We further calculate V L-23-edge absorption spectra of vanadium oxides with similar VO6 octahedral environment for formal d electrons varying from 3d(0) to 3d(3), where we obtain energy parameters representing the local ground-state properties and provide the theoretical guidance for identifying the chemical valence and the crystal-field strength of a particular vanadium oxide. Our simulated polarization-dependent spectra at different tetragonal crystal-field values reveal a nonlinear orbital-lattice interaction. The orbital polarization P reflecting the electron occupations in different d(xy) and d(xz(yz)) orbital symmetries shows strong sensitivity to small tetragonal crystal field, indicating the strongly correlated electron effect and further addressing the efficiency of strain engineering in functional SVO-based thin films and heterostructures.