DOI: 10.17188/1284293
title: Materials Data on KSn2F5 by Materials Project

description: KSn2F5 crystallizes in the trigonal P3 space group. The structure is two-dimensional and consists of two K3Sn6F14 sheets oriented in the (0, 0, 1) direction; two K3Sn6F16 sheets oriented in the (0, 0, 1) direction; and two KSn2F5 sheets oriented in the (0, 0, 1) direction. In each K3Sn6F14 sheet, there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of K–F bond distances ranging from 2.66–2.98 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.69–3.18 Å. In the third K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.73–2.96 Å. There are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded in a distorted rectangular see-saw-like geometry to four F1- atoms. There are a spread of Sn–F bond distances ranging from 2.08–2.42 Å. In the second Sn2+ site, Sn2+ is bonded in a rectangular see-saw-like geometry to four F1- atoms. There are a spread of Sn–F bond distances ranging from 2.06–2.41 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Sn2+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to one K1+ and two equivalent Sn2+ atoms. In the third F1- site, F1- is bonded to one K1+ and three equivalent Sn2+ atoms to form a mixture of distorted edge and corner-sharing FKSn3 trigonal pyramids. In the fourth F1- site, F1- is bonded in a distorted trigonal planar geometry to one K1+ and three equivalent Sn2+ atoms. In the fifth F1- site, F1- is bonded to three K1+ and one Sn2+ atom to form distorted FK3Sn tetrahedra that share corners with nine FK3Sn tetrahedra, a cornercorner with one FKSn3 trigonal pyramid, and edges with three equivalent FK3Sn tetrahedra. In the sixth F1- site, F1- is bonded to three K1+ and one Sn2+ atom to form distorted FK3Sn tetrahedra that share corners with nine FK3Sn tetrahedra, edges with three equivalent FK3Sn tetrahedra, and an edgeedge with one FKSn3 trigonal pyramid. In each K3Sn6F16 sheet, there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a body-centered cubic geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.68–2.89 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.71–3.19 Å. In the third K1+ site, K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.70–3.16 Å. There are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded to five F1- atoms to form distorted corner-sharing SnF5 square pyramids. There are a spread of Sn–F bond distances ranging from 2.05–2.50 Å. In the second Sn2+ site, Sn2+ is bonded to five F1- atoms to form distorted corner-sharing SnF5 square pyramids. There are a spread of Sn–F bond distances ranging from 2.05–2.50 Å. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Sn2+ atoms. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Sn2+ atoms. In the third F1- site, F1- is bonded to one K1+ and three equivalent Sn2+ atoms to form FKSn3 trigonal pyramids that share corners with three equivalent FK3Sn tetrahedra, a cornercorner with one FKSn3 trigonal pyramid, and edges with three equivalent FK3Sn tetrahedra. In the fourth F1- site, F1- is bonded to one K1+ and three equivalent Sn2+ atoms to form FKSn3 trigonal pyramids that share corners with three equivalent FK3Sn tetrahedra, a cornercorner with one FKSn3 trigonal pyramid, and edges with three equivalent FK3Sn tetrahedra. In the fifth F1- site, F1- is bonded in a distorted trigonal planar geometry to one K1+ and three equivalent Sn2+ atoms. In the sixth F1- site, F1- is bonded in a distorted trigonal planar geometry to one K1+ and three equivalent Sn2+ atoms. In the seventh F1- site, F1- is bonded to three K1+ and one Sn2+ atom to form distorted FK3Sn tetrahedra that share corners with nine FK3Sn tetrahedra, a cornercorner with one FKSn3 trigonal pyramid, edges with three equivalent FK3Sn tetrahedra, and an edgeedge with one FKSn3 trigonal pyramid. In the eighth F1- site, F1- is bonded to three K1+ and one Sn2+ atom to form distorted FK3Sn tetrahedra that share corners with nine FK3Sn tetrahedra, a cornercorner with one FKSn3 trigonal pyramid, edges with three equivalent FK3Sn tetrahedra, and an edgeedge with one FKSn3 trigonal pyramid. In each KSn2F5 sheet, there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.57–3.22 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of K–F bond distances ranging from 2.57–3.00 Å. In the third K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.71–2.85 Å. There are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded in a rectangular see-saw-like geometry to four F1- atoms. There are a spread of Sn–F bond distances ranging from 1.99–2.40 Å. In the second Sn2+ site, Sn2+ is bonded to five F1- atoms to form distorted corner-sharing SnF5 square pyramids. There are a spread of Sn–F bond distances ranging from 2.13–2.51 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Sn2+ atoms. In the second F1- site, F1- is bonded in a distorted T-shaped geometry to one K1+ and two equivalent Sn2+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to one K1+ and three equivalent Sn2+ atoms. In the fourth F1- site, F1- is bonded to one K1+ and three equivalent Sn2+ atoms to form FKSn3 trigonal pyramids that share corners with three equivalent FKSn3 trigonal pyramids and edges with three equivalent FK3Sn tetrahedra. In the fifth F1- site, F1- is bonded to one K1+ and three equivalent Sn2+ atoms to form FKSn3 trigonal pyramids that share corners with three equivalent FKSn3 trigonal pyramids and edges with three equivalent FK3Sn tetrahedra. In the sixth F1- site, F1- is bonded to three K1+ and one Sn2+ atom to form distorted FK3Sn tetrahedra that share corners with six equivalent FK3Sn tetrahedra and edges with two FKSn3 trigonal pyramids. In the seventh F1- site, F1- is bonded in a 1-coordinate geometry to three K1+ and one Sn2+ atom.