Cluster model and band structure calculations ofV2O5: ReducedV5+symmetry and many-body effects

Abstract

We studied the electronic structure of the ${\mathrm{V}}_{2}{\mathrm{O}}_{5}$ compound using cluster model calculations. The calculation included the reduced ${\mathrm{V}}^{5+}$ symmetry and the strong $\mathrm{V}\phantom{\rule{0.2em}{0ex}}3d--\mathrm{O}\phantom{\rule{0.2em}{0ex}}2p$ covalence effects. The many-body effects are taken into account using the configuration interaction method. The ground state of ${\mathrm{V}}_{2}{\mathrm{O}}_{5}$ is highly covalent and dominated by the $3{d}^{1}\underset{}{L}$ $(^{1}A_{1})$ configuration, where $\underset{}{L}$ denotes a ligand hole. The ${\mathrm{V}}_{2}{\mathrm{O}}_{5}$ material is in the charge-transfer regime and the band gap is due to $p\text{\ensuremath{-}}d$ transitions. The first removal state is given by the $3{d}^{0}\underset{}{L}$ $(^{2}A_{1})$ configuration, and the first addition state is formed by the $3{d}^{1}$ $(^{2}E)$ configuration. The results of the cluster model are in good agreement with band structure calculations. The calculation results are also in good agreement with photoemission and x-ray absorption spectra. The $\mathrm{V}\phantom{\rule{0.2em}{0ex}}2p$ core-level spectra exhibit many-body effects despite the nominal $3{d}^{0}$ occupancy. These effects and the reduced ${\mathrm{V}}^{5+}$ symmetry are crucial to describe the electronic structure of ${\mathrm{V}}_{2}{\mathrm{O}}_{5}$.