ELECTRON DIFFERENCE DENSITY AND VIBRATION TENSORS IN SRTIO3

Multiple data sets for strontium titanate SrTiO3; M(r) = 183.5 1, cubic, Pm3mBAR a = 3.9092 (4) angstrom, V = 59.740 (3) angstrom3, z = 1, D(x) = 5.101 Mg m-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 26.489 mm-1, F(000) = 84, T= 298K, refinement indices range R = 0.013-0.028, wR = 0.012-0.028 for 91 unique reflections. Seven structure refinements from five different flux-grown crystals of SrTiO3 are compared. The specimens selected showed mild to modest extinction. In all cases the mean-square vibration amplitude for the Ti atom along the Ti-O bond markedly exceeds that for the O atom. The amplitudes of the cations are low for the two data sets most affected by extinction. The atomic charges determined for these data sets are also outliers, but their values are not concordant with each other - a result attributable to the erratic extinction for the 011 reflection and its equivalents.