RbSn2(PO4)3, a NASICON-type phosphate

Abstract

The title compound, rubidium ditin(IV) tris(phosphate), RbSn 2(PO4)3, belongs to the NASICON-type family of phosphates and crystallizes in the space group R3̄. The structure is composed of PO4 tetrahedra (1 symmetry) and two slightly distorted SnO6 octahedra, both with 3. symmetry, which are interlinked through corner-sharing O atoms to form a ∞3[Sn 2(PO4)3]̄ framework. The Rb+ cations are located on threefold inversion axes in the voids of this framework and exhibit a coordination number of 12. The crystal studied was twinned by merohedry with a component ratio of 0.503:0.497.