Electron density in YTiO2

摘要

Accurate electron density analyses have been performed on the title compound, yttrium titanate, at room and low temperature using W K alpha radiation. Room-and low-temperature Delta rho maps are generally consistent. Difference electron densities near the two symmetrically independent O atoms differ markedly. These observations may have significance for understanding the role of the O atom in mediating d-electron interactions between neighbouring Ti coordination polyhedra. Features having lower symmetry than that of the approximately octahedral local environment are observed within the Ti coordination octahedron. Crystal data at room temperature: YTiO3, M-r = 184.79, T = 293K, Pnma, a = 5.6901 (4), b = 7.6130 (7), c = 5.3381 (6) Angstrom, V = 231.24 (4) Angstrom(3), Z = 4, D-x = 5.308 Mg m(-3), mu(W K alpha) = 1.02 mm(-1), R = 0.024, wR = 0.017, S = 1.64 (2) for 2996 independent reflections. Low temperature: T = 127K, Pnma, a = 5.690 (4), b = 7.583 (6), c = 5.318 (5) Angstrom, V = 229.5 (3) Angstrom(3), D-x = 5.35 Mg m(-3), mu(W K alpha) = 1.02 mm(-1), R = 0.021, wR = 0.015, S = 1.80 (2) for 2968 independent reflections.