Materials Data on Li5FeF8 by Materials Project
Li5FeF8 crystallizes in the orthorhombic Cmmm 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 LiF6 octahedra that share corners with six equivalent LiF6 octahedra, edges with two equivalent FeF6 octahedra, and edges with six LiF6 octahedra. The corner-sharing octahedra tilt angles range from 8–14°. There are a spread of Li–F bond distances ranging from 2.00–2.21 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share edges with two equivalent FeF6 octahedra and edges with eight equivalent LiF6 octahedra. There are two shorter (1.96 Å) and four longer (2.04 Å) Li–F bond lengths. Fe3+ is bonded to six F1- atoms to form FeF6 octahedra that share edges with ten LiF6 octahedra. There is four shorter (1.95 Å) and two longer (1.96 Å) Fe–F bond length. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded to five Li1+ atoms to form a mixture of edge and corner-sharing FLi5 square pyramids. In the second F1- site, F1- is bonded to four equivalent Li1+ and one Fe3+ atom to form a mixture of edge and corner-sharing FLi4Fe square pyramids. In the third F1- site, F1- is bonded in a rectangular see-saw-like geometry to three Li1+ and one Fe3+ atom.