DOE OSTI2020
Na2SnO6 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.48–2.57 Å. Sn is bonded to six O atoms to form edge-sharing SnO6 octahedra. There are four shorter (2.09 Å) and two longer (2.22 Å) Sn–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded to three equivalent Na and two equivalent Sn atoms to form distorted ONa3Sn2 square pyramids that share corners with two equivalent ONa3Sn2 square pyramids, corners with four equivalent ONa2SnO tetrahedra, edges with five equivalent ONa3Sn2 square pyramids, and edges with three equivalent ONa2SnO tetrahedra. In the second O site, O is bonded to two equivalent Na, one Sn, and one O atom to form distorted ONa2SnO tetrahedra that share corners with four equivalent ONa3Sn2 square pyramids, corners with three equivalent ONa2SnO tetrahedra, and edges with three equivalent ONa3Sn2 square pyramids. The O–O bond length is 1.35 Å. In the third O site, O is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na and one O atom.