Materials Data on KNaSnF6 by Materials Project

Abstract

NaKSnF6 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.76–2.87 Å. Na1+ is bonded to six F1- atoms to form NaF6 octahedra that share corners with four equivalent SnF6 octahedra and an edgeedge with one SnF6 octahedra. The corner-sharing octahedra tilt angles range from 33–45°. There are a spread of Na–F bond distances ranging from 2.24–2.55 Å. Sn4+ is bonded to six F1- atoms to form SnF6 octahedra that share corners with four equivalent NaF6 octahedra and an edgeedge with one NaF6 octahedra. The corner-sharing octahedra tilt angles range from 33–45°. There are a spread of Sn–F bond distances ranging from 2.00–2.03 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and one Sn4+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and one Sn4+ atom. In the third F1- site, F1- is bonded in a distorted rectangular see-saw-like geometry to two equivalent K1+, one Na1+, and one Sn4+ atom. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and one Sn4+ atom. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to one K1+, one Na1+, and one Sn4+ atom. In the sixth F1- site, F1- is bonded to two equivalent K1+, one Na1+, and one Sn4+ atom to form distorted corner-sharing FK2NaSn tetrahedra.