A DFT study on the correlation between topology and Bader charges: Part II, effects of compression and dilatation of V2O5

Starting from known structures of the modifications of V2O5 (alpha, gamma ') we investigate the results of relaxations in DFT calculations performed at different fixed volumes per formula unit on keeping the axis relations and the symmetry of the original space groups. We analyse the correlation between the topology of a structure, i.e. the co-ordination geometry and the distances observed, with the charges of the atoms as derived from a Bader analysis of the electron distribution. A similar study follows the development of the structural topology and the charges of a high pressure variant (beta-V2O5) on dilatation of the structure in several steps. All structural variations follow the known rules known for high temperature and high pressure reactions, and the changes of the charges can be rationalized in terms of structural parameters. (C) 2015 Elsevier Masson SAS. All rights reserved.