A DFT study on the correlation between topology and Bader charges: Part I, effects of compression and expansion of As2O5

• We present a DFT study of modifications of As2O5 in different specified volumes.
• The correlation between structural topology and Bader charges of the atoms is shown.
• We trace the relation between charges and connectivity in co-ordination structures.
• The results represent the known crystal chemical rules of high pressure transitions.

Starting from known structures of the modifications of As2O5 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 group. 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 form a Bader analysis of the electron distribution resulting from a DFT relaxation. A similar study is done on the changes of the structure and the charges as a result of a relaxation without such a symmetry bias giving a new hitherto unknown possible high pressure structure.

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