A study on AB₂O₆compounds, Part V: a DFT study on charge balance as driving force for structural organisation

Abstract

In continuation of earlier investigations on the structures of AB 2 O 6 compounds we have remodelled those with A = Ca, Sr, Ba and B = As, Sb, V, Nb, Ta by relaxation in DFT calculations with the VASP code. The results match the real structures very closely. We have then calculated charges of the constituent atoms by means of a Bader analysis of the calculated electron density distribution. The results of these calculations are discussed with the aim to establish a correlation between the charges of the atoms and the vicinity structure around the atoms. Similar calculations were done first for all these compounds in a rosiaite type structure and second for CaAs 2 O 6 in all the other structures found for these compounds. We discuss how the balance of charges changes on forcing the systems into another topology, and we finally address the issue that structural organisation is strongly determined by the need to balance charges of the constituting elements in their specific stoichiometric relation.

A DFT study on the correlation between topology and Bader charges: Part III, the development of charge, “size” and coordination in alkali and alkaline earth titanates(IV)

“…We have found similar trends in other ternary series. In an earlier paper [15] we have demonstrated how the charge balance works when the transition metal changes but the stoichiometric composition is preserved. To that end we have reviewed a great number of AB 2 O 6 compounds with respect to the coordination formulae on the one hand and the development of charges as derived from a similar Bader analysis on the other hand.…”

A DFT study on the correlation between topology and Bader charges: Part IV, on the change of atomic charges in polymorphic transitions – A case study on CaCl 2

“…However, it is the notion of this and foregoing papers to put forward the idea that there is a stringent correlation between these numbers and the topology which we observe. We have demonstrated in the first parts of this series how Bader charges change on deforming structures (Part I and II [15,16]) and on changing the chemistry in a continuous series of compounds (Part III [17]). One may not give a cent for the numbers themselves which result from these calculations of the charges, but we do believe that their relation has a meaning and also the way they change on deforming structures or on changing them under pressure or at higher temperatures.…”

Theoretical Investigation on Highly Efficient Quinacridone Derivatives for Green Dopant OLEDs: A DFT Simulation

“…In earlier, the balance of charges in different constellations of elements acts as a driving force for structural organization [38]. This infers also that charges will change when changing the structure [39,40]. The atomic charges were calculated by a Bader analysis.…”