Alternative presentation of the Brown-Wu bond-valence parameters for some s2 cation/O2- ion pairs

Using the least-squares refinement procedure, high-performance Brown-Wu bond-valence parameters, r(0) and n, reported for the Sn2+/O2-, Sb3+/O2-, Te4+/O2- and I5+/O2- ion pairs have been converted into the commonly used bond-valence parameters, r(0) and b. The r(0) and b values obtained can be recommended as a replacement for the conventional bond-valence parameters based on the 'universal constant' b = 0.37 angstrom.