Materials Data on Li3Fe2F7 by Materials Project

Abstract

Li3Fe2F7 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four F1- atoms. There are a spread of Li–F bond distances ranging from 1.82–2.13 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share corners with two equivalent FeF6 octahedra and edges with four equivalent FeF6 octahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of Li–F bond distances ranging from 1.98–2.29 Å. Fe2+ is bonded to six F1- atoms to form FeF6 octahedra that share a cornercorner with one LiF6 octahedra, corners with three equivalent FeF6 octahedra, an edgeedge with one FeF6 octahedra, and edges with two equivalent LiF6 octahedra. The corner-sharing octahedra tilt angles range from 46–61°. There are a spread of Fe–F bond distances ranging from 1.97–2.26 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded to two Li1+ and two equivalent Fe2+ atoms to form a mixture of distorted edge and corner-sharing FLi2Fe2 trigonal pyramids. In the second F1- site, F1- is bonded to two Li1+ and two equivalent Fe2+ atoms to form a mixture of distorted edge and corner-sharing FLi2Fe2 trigonal pyramids. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom. In the fourth F1- site, F1- is bonded to two equivalent Li1+ and two equivalent Fe2+ atoms to form corner-sharing FLi2Fe2 tetrahedra.