Materials Data on K5ThF9 by Materials Project

Abstract

K5ThF9 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. 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 2.64–3.22 Å. In the second 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 2.66–3.27 Å. In the third K1+ site, K1+ is bonded to seven F1- atoms to form distorted corner-sharing KF7 pentagonal bipyramids. There are a spread of K–F bond distances ranging from 2.62–3.06 Å. Th4+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Th–F bond distances ranging from 2.32–2.44 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded to six K1+ atoms to form FK6 octahedra that share corners with two equivalent FK6 octahedra, corners with two equivalent FK4Th square pyramids, an edgeedge with one FK4Th square pyramid, and faces with two equivalent FK5Th octahedra. The corner-sharing octahedral tilt angles are 40°. In the second F1- site, F1- is bonded to four K1+ and one Th4+ atom to form distorted FK4Th square pyramids that share corners with four FK6 octahedra, an edgeedge with one FK6 octahedra, and a faceface with one FK5Th octahedra. The corner-sharing octahedra tilt angles range from 38–47°. In the third F1- site, F1- is bonded in a 5-coordinate geometry to four K1+ and one Th4+ atom. In the fourth F1- site, F1- is bonded in a 5-coordinate geometry to four K1+ and one Th4+ atom. In the fifth F1- site, F1- is bonded to five K1+ and one Th4+ atom to form distorted FK5Th octahedra that share corners with two equivalent FK4Th square pyramids, faces with two equivalent FK6 octahedra, and a faceface with one FK4Th square pyramid. In the sixth F1- site, F1- is bonded in a 5-coordinate geometry to four K1+ and one Th4+ atom. In the seventh F1- site, F1- is bonded in a 5-coordinate geometry to four K1+ and one Th4+ atom.