Materials Data on LiFeF4 by Materials Project

Abstract

LiFeF4 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of two LiFeF4 sheets oriented in the (0, 0, 1) direction. Li1+ is bonded to five F1- atoms to form LiF5 square pyramids that share corners with six equivalent FeF6 octahedra and edges with two equivalent LiF5 square pyramids. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Li–F bond distances ranging from 2.02–2.05 Å. Fe3+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with six equivalent LiF5 square pyramids and edges with two equivalent FeF6 octahedra. There are a spread of Fe–F bond distances ranging from 1.91–2.03 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent Li1+ and one Fe3+ atom. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two equivalent Fe3+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent Li1+ and one Fe3+ atom. In the fourth F1- site, F1- is bonded in a water-like geometry to two equivalent Fe3+ atoms.