Materials Data on Li2FeF5 by Materials Project

Abstract

Li2FeF5 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five F1- atoms to form distorted LiF5 square pyramids that share corners with four equivalent FeF7 pentagonal bipyramids, corners with two equivalent LiF5 square pyramids, an edgeedge with one FeF7 pentagonal bipyramid, and edges with three equivalent LiF5 square pyramids. There are a spread of Li–F bond distances ranging from 1.96–2.22 Å. In the second Li1+ site, Li1+ is bonded to five F1- atoms to form distorted LiF5 square pyramids that share corners with four equivalent FeF7 pentagonal bipyramids, corners with two equivalent LiF5 square pyramids, an edgeedge with one FeF7 pentagonal bipyramid, and edges with three equivalent LiF5 square pyramids. There are a spread of Li–F bond distances ranging from 1.96–2.22 Å. Fe3+ is bonded to seven F1- atoms to form distorted FeF7 pentagonal bipyramids that share corners with eight LiF5 square pyramids, edges with two equivalent FeF7 pentagonal bipyramids, and edges with two LiF5 square pyramids. There are a spread of Fe–F bond distances ranging from 1.93–2.14 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded to four Li1+ and one Fe3+ atom to form distorted edge-sharing FLi4Fe trigonal bipyramids. In the second F1- site, F1- is bonded in a distorted 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 equivalent Fe3+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent Fe3+ atoms. In the fifth F1- site, F1- is bonded in a trigonal planar geometry to two Li1+ and one Fe3+ atom.