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

Density-functional theory ~DFT! studies are performed to examine geometric and electronic properties of orthorhombic bulk V2O5 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 V2O5(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 V2O5(010) single-layer slabs, represented by their valence densities of states ~DOS! and its atom contributions, is compared with results of bulk V2O5 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 V2O5. Further, the computed valence DOS is used to interpret recent experimental results from photoemission on V2O5(010), which suggests that differently coordinated oxygen sites at the surface can be identified in the spectrum. Thus, V2O5(010) photoemission spectra may be used to monitor the participation of oxygen ions in respective surface reactions. @S0163-1829~99!03616-4#