Distortion of V z+O n coordination polyhedra and parameters of the bond valence model for V-O bonds in inorganic crystals

The dependences of average V-O distances in inorganic compounds of vanadium of different valence on the degree of distortion of coordination polyhedra have been obtained by careful statistical treatment of modern structural data banks. Values of bond lengths in undistorted (regular) polyhedra are recommended. Theoretical analysis of the statistical data made it possible to calculate the most likely values of the parameters of the bond valence model: the interatomic distance for the single (two-electron) bond, corresponding to the single valence, and the bond softness parameter. Calculations of the sums of bond valences for some complicated cases (different coordination numbers, mixed vanadium valence) confirmed reliability of the recommended parameters.