Crystal structure of a new stoichiometric compound: Bi2Te5WO16 deriving from fluorite type

The new Bi2Te5WO16 compound has been prepared and its structure has been determined by single crystal X-ray diffraction: space group: P2/n (no. 13) with unit cell parameters a=11.409(1)Å, b=5.673(1)Å, c=12.253(1)Å, β=116.68(1)° and Z=2 formula units. The structure was determined from 1975 reflections, the final R1 and Rw indices are 0.037 and 0.071, respectively. The structure derives from the fluorite structure MX2. It can be described as [Bi2Te3O12] layers parallel to (−1 0 1) alternating in the direction [1 0 −1] by WO6 octahedron. The lone pairs of tellurium, active, localised in the pseudo-rectangular tunnels are oriented parallel to Oy-axis between [Bi2Te3O12] layers.