Crystal structure of K2ZnSi3O8

The structure of K 2 ZnSi 3 O 8 has been determined using Rietveld analysis of X-ray powder diffraction data (R p = 3.99%). With space group Imam and cell dimensions a = 5.285(1), b = 9.058(1), c = 8.535(1) A, tetrahedrally coordinated Zn and Si atoms are disordered over one crystallographic site forming at tecto-(zincio)silicate structure with 8-coordinated K atoms in intervening large cavities. This is the first example of the aristotype of the NH 4 LiSO 4 family of general formula, AT 2 O 4 , where A is a large alkali (or pseudo-alkali) atom and T represents tetrahedrally-coordinated atoms including: Al, Be, Co, Li, Mg, P, S, Si, and Zn