Geometric and electronic structure of vanadium pentoxide: A density functional bulk and surface study

Abstract

Density-functional theory (DFT) studies are performed to examine geometric and electronic properties of orthorhombic bulk ${\mathrm{V}}_{2}{\mathrm{O}}_{5}$ as well as of its (010) oriented surface. Electronic states, total energies, as well as atom forces (used to obtain equilibrium geometries) are computed with the ab initio full-potential linear augmented plane wave method. The ${\mathrm{V}}_{2}{\mathrm{O}}_{5}(010)$ surface is modeled by periodic single layers in a repeated slab geometry, which is justified by the weak electronic interlayer coupling found in the bulk calculations. The electronic structure of the ${\mathrm{V}}_{2}{\mathrm{O}}_{5}(010)$ single-layer slabs, represented by their valence densities of states (DOS) and its atom contributions, is compared with results of bulk ${\mathrm{V}}_{2}{\mathrm{O}}_{5}$ and with previous results obtained by DFT surface cluster studies. The comparison yields good qualitative agreement between the different approaches, which confirms the local nature of interatomic binding in ${\mathrm{V}}_{2}{\mathrm{O}}_{5}.$ Further, the computed valence DOS is used to interpret recent experimental results from photoemission on ${\mathrm{V}}_{2}{\mathrm{O}}_{5}(010),$ which suggests that differently coordinated oxygen sites at the surface can be identified in the spectrum. Thus, ${\mathrm{V}}_{2}{\mathrm{O}}_{5}(010)$ photoemission spectra may be used to monitor the participation of oxygen ions in respective surface reactions.