Materials Data on Cs3Fe2F9 by Materials Project

Abstract

Cs3Fe2F9 crystallizes in the hexagonal P-62c space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to twelve F1- atoms to form distorted CsF12 cuboctahedra that share corners with six equivalent CsF12 cuboctahedra and faces with six equivalent FeF6 octahedra. There are a spread of Cs–F bond distances ranging from 3.12–3.26 Å. In the second Cs1+ site, Cs1+ is bonded in a 12-coordinate geometry to twelve F1- atoms. There are a spread of Cs–F bond distances ranging from 3.19–3.63 Å. Fe3+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share faces with three equivalent CsF12 cuboctahedra and a faceface with one FeF6 octahedra. There is three shorter (1.89 Å) and three longer (2.08 Å) Fe–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted L-shaped geometry to four Cs1+ and two equivalent Fe3+ atoms. In the second F1- site, F1- is bonded in a single-bond geometry to four Cs1+ and one Fe3+ atom.