Materials Data on K2Sn3O7 by Materials Project
K2Sn3O7 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.82–2.93 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.76–2.85 Å. There are three inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing SnO6 octahedra. The corner-sharing octahedra tilt angles range from 43–51°. There are a spread of Sn–O bond distances ranging from 2.00–2.20 Å. In the second Sn4+ site, Sn4+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Sn–O bond distances ranging from 2.07–2.16 Å. In the third Sn4+ site, Sn4+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of Sn–O bond distances ranging from 2.05–2.25 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Sn4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and three Sn4+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two Sn4+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three equivalent Sn4+ atoms. In the fifth O2- site, O2- is bonded to three equivalent K1+ and two equivalent Sn4+ atoms to form distorted edge-sharing OK3Sn2 square pyramids. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Sn4+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to three K1+ and two equivalent Sn4+ atoms.