Mixed oxides of titanium and niobium. II. The crystal structures of the dimorphic forms Ti2Nb10O29

MIXED OXIDES OF TITANIUM AND NIOBIUM.I distances 1. 95 and 2.76 A between metal and anion, anion and anion respectively in Nb02F; Vousden (1951) 2.00 and 2.82 A for KNbOs, 1.95 and 2-76/~ for NaNb0s; BystrSm's (1944) data for the pyrochlor structure, based upon indirect methods, is not included.Complex structures such as this one are not readily described in terms of the individual atoms of which they are composed; since it bears a close resemblance to those of the twoforms of Ti2Nb10029 which are found in the system Ti0~-Nb20~, the three structures will be discussed together in the following paper as members of an homologous series (Wadsley, 1961).