Electron density study of spinels: Magnesium gallium oxide

The electron density distribution in magnesium gallium oxide spinel [composition MgGa2O4; for the general formula TX2O4, tetrahedral site T = MgxGa1 − x, octahedral site X = Ga1 + xMg1 − x; x = 0.183(4)] has been studied with single-crystal X-ray diffraction methods through scattering factor refinement procedures. A residual 0.95e/Å3 height in harmonic refinement (0.75e/Å3 for anharmonic) is situated at the center of the X4O4 cuboidal unit. Residuals around T and X seen in the harmonic refinement disappear in the anharmonic refinement, the T-O distance increasing from 1.8919(5)Å in harmonic to 1.899(2)Å for anharmonic refinements. [191 equivalent-averaged reflexions, R = 0.0078 (harmonic refinement), R = 0.0067 (anharmonic refinement)].