Materials Data on Li2Fe3F8 by Materials Project

Abstract

Li2Fe3F8 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with nine FeF6 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Li–F bond distances ranging from 1.89–1.99 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with six equivalent LiF4 tetrahedra and edges with four FeF6 octahedra. There are a spread of Fe–F bond distances ranging from 2.04–2.23 Å. In the second Fe2+ site, Fe2+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with six equivalent LiF4 tetrahedra and edges with four equivalent FeF6 octahedra. There are four shorter (2.10 Å) and two longer (2.12 Å) Fe–F bond lengths. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two Fe2+ atoms. In the second F1- site, F1- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Fe2+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two equivalent Fe2+ atoms.