Electronic Structure of Triclinic Tungstate CuWO4: Experiment and Theory

We report on theoretical and experimental studies of the electronic structure of triclinic copper tungstate, CuWO 4 . The present data carried out within a Density Functional theory (DFT) framework reveal the importance of spin-resolved calculations for this tungstate. The spin-resolved DFT calculations indicate that that Cu 3d electronic states dominate the top of the valence band, whereas the main input of W 5d states occur at its bottom and lower part. However, the principal contributions to the valence band of CuWO 4 come from O 2p electronic states giving the main input to the whole valence-band region except of its top. The chemical bonding in CuWO 4 is characterized by essential contribution of the covalent component in addition to the ionic component. The present theoretical data are found to be in excellent agreement with the experimental XPS and XES measurements of polycrystalline copper tungstate.