A neutron‐diffraction study of magnesium aluminium oxide

were established by considering the ratio of the intensities, IhkdIh~, thereby reducing errors arising from absorption effects. The x coordinate was obtained b y considering those reflections hkO for which Ii, k0 = 0. The determination of u and z then involved essentially a trial-and-error procedure. However, using reasonable K F distances, these parameters could be determined with a minimum of effort. The final values are: u = 0.700±0.004, x ---0.156±0.003, and z ---0-244±0.004. A comparison between observed and calculated structure factors is given in Table 1. Absorption and temperature corrections are not included. T H E CRYSTAL S T R U C T U R E OF K~TiF6