Bi12(Bi0.5IIITl0.5III)O19.50

Abstract

The structure of the sillenite-type title compound has been determined at room temperature by singlecrystal neutron diffraction. Tl III O 4 tetrahedra are replaced statistically by Bi III O 3 groups, statistically oriented with respect to the threeshold axis. The distances in the TlO 4 tetrahedra and BiO 3 groups are 2.116 (9) and 2.02 (2) A, respectively