Materials Data on KEr2F7 by Materials Project

Abstract

KEr2F7 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 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.59–3.25 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 2.72–3.29 Å. There are three inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Er–F bond distances ranging from 2.22–2.38 Å. In the second Er3+ site, Er3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Er–F bond distances ranging from 2.19–2.69 Å. In the third Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Er–F bond distances ranging from 2.14–2.43 Å. There are ten inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to one K1+ and two Er3+ atoms. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to two Er3+ atoms. In the third F1- site, F1- is bonded in a 4-coordinate geometry to one K1+ and three Er3+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to two K1+ and two Er3+ atoms. In the fifth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two K1+ and two Er3+ atoms. In the sixth F1- site, F1- is bonded in a distorted tetrahedral geometry to one K1+ and three Er3+ atoms. In the seventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to three Er3+ atoms. In the eighth F1- site, F1- is bonded in a 3-coordinate geometry to one K1+ and three Er3+ atoms. In the ninth F1- site, F1- is bonded in a 4-coordinate geometry to two K1+ and two equivalent Er3+ atoms. In the tenth F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+ and two Er3+ atoms.