Distortions in octahedrally coordinated d0 transition metal oxides:: A continuous symmetry measures approach

More than 750 d(0) transition metal oxide octahedra have been examined in order to better understand the out-of-center distortion occurring with these cations. A continuous symmetry measures approach was used to quantify the magnitude and direction of the distortion. Using this approach we were able to divide the d0 transition metals into three categories: strong ( Mo6+ and V5+), moderate ( W6+, Ti4+, Nb5+, and Ta5+), and weak ( Zr4+ and Hf4+) distorters. We also examined and discussed the directional preference of the distortion for each cation.