Materials Data on LiFeF4 by Materials Project

Abstract

LiFeF4 is zeta iron carbide-derived structured and crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six F1- atoms to form distorted LiF6 octahedra that share corners with four equivalent LiF6 octahedra, corners with four FeF6 octahedra, and edges with two FeF6 octahedra. The corner-sharing octahedra tilt angles range from 48–58°. There are a spread of Li–F bond distances ranging from 2.04–2.30 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form distorted LiF6 octahedra that share corners with four equivalent LiF6 octahedra, corners with four FeF6 octahedra, and edges with two FeF6 octahedra. The corner-sharing octahedra tilt angles range from 47–59°. There are a spread of Li–F bond distances ranging from 2.02–2.39 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with four LiF6 octahedra, edges with two LiF6 octahedra, and edges with two equivalent FeF6 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Fe–F bond distances ranging from 1.90–2.02 Å. In the second Fe3+ site, Fe3+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with four LiF6 octahedra, edges with two LiF6 octahedra, and edges with two equivalent FeF6 octahedra. The corner-sharing octahedra tilt angles range from 47–59°. There are a spread of Fe–F bond distances ranging from 1.88–2.05 Å. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two Fe3+ atoms. In the second F1- site, F1- is bonded in a trigonal planar geometry to two Li1+ and one Fe3+ atom. In the third F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two Fe3+ atoms. In the fourth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe3+ atom. In the fifth F1- site, F1- is bonded in a trigonal planar geometry to two Li1+ and one Fe3+ atom. In the sixth F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two Fe3+ atoms. In the seventh F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe3+ atom. In the eighth F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two Fe3+ atoms.