Structure of cubic aluminate sodalite, Sr8[Al12O24](CrO4)2

Abstract

The title compd. is cubic, space group I.hivin.43m, with a 9.427(2) .ANG.; dc = 3.25 for Z = 1. The final R = 0.045 for 256 reflections. The at. coordinates are given. The sodalite framework is (almost) fully expanded, therefore space group Im.hivin.3m is also possible. The corresponding refinement gave results almost identical with that in I.hivin.43m (R = 0.048 for 149 reflections). The tetrahedral CrO4 cage anion is 6-fold disordered; only the superposition corresponds to cubic symmetry.