DOI: 10.17188/1308370
title: Materials Data on Li2Fe4OF8 by Materials Project

description: Li2Fe4OF8 is beta indium sulfide-derived structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to two O2- and four F1- atoms to form distorted LiO2F4 octahedra that share corners with four FeF6 octahedra, corners with two equivalent FeF5 trigonal bipyramids, corners with three FeO2F2 trigonal pyramids, and edges with three FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 15–60°. There are one shorter (2.01 Å) and one longer (2.11 Å) Li–O bond lengths. There are a spread of Li–F bond distances ranging from 2.05–2.62 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share corners with four FeO2F4 octahedra, corners with two FeO2F2 trigonal pyramids, edges with three FeF6 octahedra, and an edgeedge with one FeF5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 46–59°. There are a spread of Li–F bond distances ranging from 2.04–2.23 Å. In the third Li1+ site, Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share corners with four FeOF5 octahedra, a cornercorner with one FeF5 trigonal bipyramid, corners with three FeO2F2 trigonal pyramids, and edges with three FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 13–58°. There are a spread of Li–F bond distances ranging from 2.07–2.19 Å. In the fourth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Li–F bond distances ranging from 1.91–2.45 Å. There are eight inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to two O2- and four F1- atoms to form distorted FeO2F4 octahedra that share corners with two equivalent LiF6 octahedra, corners with two FeF6 octahedra, a cornercorner with one FeF5 trigonal bipyramid, corners with three FeO2F2 trigonal pyramids, edges with two LiO2F4 octahedra, and edges with two FeF6 octahedra. The corner-sharing octahedra tilt angles range from 46–60°. There are one shorter (2.01 Å) and one longer (2.08 Å) Fe–O bond lengths. There are a spread of Fe–F bond distances ranging from 2.10–2.42 Å. In the second Fe2+ site, Fe2+ is bonded to two O2- and two F1- atoms to form distorted FeO2F2 trigonal pyramids that share corners with four LiO2F4 octahedra, corners with five FeO2F4 octahedra, and an edgeedge with one FeOF3 trigonal pyramid. The corner-sharing octahedra tilt angles range from 53–67°. There is one shorter (1.89 Å) and one longer (1.96 Å) Fe–O bond length. There are one shorter (2.12 Å) and one longer (2.19 Å) Fe–F bond lengths. In the third Fe2+ site, Fe2+ is bonded to one O2- and five F1- atoms to form FeOF5 octahedra that share a cornercorner with one FeF6 octahedra, corners with two LiF6 octahedra, a cornercorner with one FeF5 trigonal bipyramid, a cornercorner with one FeO2F2 trigonal pyramid, edges with two equivalent LiO2F4 octahedra, edges with two FeO2F4 octahedra, and a faceface with one FeF6 octahedra. The corner-sharing octahedra tilt angles range from 13–49°. The Fe–O bond length is 1.97 Å. There are a spread of Fe–F bond distances ranging from 2.09–2.35 Å. In the fourth Fe2+ site, Fe2+ is bonded to five F1- atoms to form distorted FeF5 trigonal bipyramids that share corners with three LiO2F4 octahedra, corners with three FeO2F4 octahedra, a cornercorner with one FeOF3 trigonal pyramid, an edgeedge with one LiF6 octahedra, and edges with two FeF6 octahedra. The corner-sharing octahedra tilt angles range from 46–68°. There are a spread of Fe–F bond distances ranging from 1.91–2.14 Å. In the fifth Fe2+ site, Fe2+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with two LiO2F4 octahedra, corners with three FeO2F4 octahedra, a cornercorner with one FeF5 trigonal bipyramid, corners with two FeO2F2 trigonal pyramids, an edgeedge with one FeF6 octahedra, and edges with two equivalent LiF6 octahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Fe–F bond distances ranging from 2.01–2.19 Å. In the sixth Fe2+ site, Fe2+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share corners with two FeO2F4 octahedra, corners with four LiO2F4 octahedra, a cornercorner with one FeO2F2 trigonal pyramid, an edgeedge with one LiF6 octahedra, an edgeedge with one FeF6 octahedra, an edgeedge with one FeF5 trigonal bipyramid, and a faceface with one FeOF5 octahedra. The corner-sharing octahedra tilt angles range from 44–60°. There are a spread of Fe–F bond distances ranging from 2.00–2.28 Å. In the seventh Fe2+ site, Fe2+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with two LiO2F4 octahedra, corners with two FeF6 octahedra, a cornercorner with one FeOF3 trigonal pyramid, edges with two equivalent LiF6 octahedra, edges with two FeO2F4 octahedra, and an edgeedge with one FeF5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 15–52°. There are a spread of Fe–F bond distances ranging from 2.04–2.21 Å. In the eighth Fe2+ site, Fe2+ is bonded to one O2- and three F1- atoms to form FeOF3 trigonal pyramids that share corners with three FeO2F4 octahedra, corners with four LiO2F4 octahedra, a cornercorner with one FeF5 trigonal bipyramid, and an edgeedge with one FeO2F2 trigonal pyramid. The corner-sharing octahedra tilt angles range from 56–70°. The Fe–O bond length is 1.90 Å. There are a spread of Fe–F bond distances ranging from 1.96–2.14 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Li1+ and three Fe2+ atoms to form OLiFe3 tetrahedra that share a cornercorner with one OLiFe3 tetrahedra, a cornercorner with one FLi2Fe2 tetrahedra, corners with five FLi2Fe2 trigonal pyramids, and an edgeedge with one OLiFe3 tetrahedra. In the second O2- site, O2- is bonded to one Li1+ and three Fe2+ atoms to form distorted OLiFe3 tetrahedra that share a cornercorner with one OLiFe3 tetrahedra, corners with two FLiFe3 tetrahedra, corners with three FLiFe3 trigonal pyramids, an edgeedge with one OLiFe3 tetrahedra, and an edgeedge with one FLi2Fe2 tetrahedra. There are sixteen inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two Fe2+ atoms. In the second F1- site, F1- is bonded in a distorted see-saw-like geometry to two Li1+ and two Fe2+ atoms. In the third F1- site, F1- is bonded in a trigonal planar geometry to two Li1+ and one Fe2+ atom. In the fourth F1- site, F1- is bonded in a 4-coordinate geometry to one Li1+ and three Fe2+ atoms. In the fifth F1- site, F1- is bonded to two Li1+ and two Fe2+ atoms to form distorted FLi2Fe2 trigonal pyramids that share a cornercorner with one OLiFe3 tetrahedra, corners with three FLiFe3 tetrahedra, corners with two FLiFe3 trigonal pyramids, and edges with two FLiFe3 trigonal pyramids. In the sixth F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form distorted FLiFe3 trigonal pyramids that share a cornercorner with one FLiFe3 tetrahedra, corners with three OLiFe3 tetrahedra, corners with two FLiFe3 trigonal pyramids, and edges with two FLi2Fe2 trigonal pyramids. In the seventh F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form distorted FLiFe3 tetrahedra that share a cornercorner with one OLiFe3 tetrahedra, corners with two FLi2Fe2 tetrahedra, corners with five FLi2Fe2 trigonal pyramids, and an edgeedge with one FLiFe3 trigonal pyramid. In the eighth F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form distorted FLiFe3 trigonal pyramids that share corners with two OLiFe3 tetrahedra, corners with three FLiFe3 tetrahedra, corners with three FLiFe3 trigonal pyramids, and an edgeedge with one FLi2Fe2 trigonal pyramid. In the ninth F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form distorted FLiFe3 trigonal pyramids that share corners with four FLiFe3 tetrahedra, corners with two FLi2Fe2 trigonal pyramids, and edges with two FLiFe3 trigonal pyramids. In the tenth F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form distorted FLiFe3 trigonal pyramids that share a cornercorner with one FLi2Fe2 tetrahedra, corners with two OLiFe3 tetrahedra, corners with three FLi2Fe2 trigonal pyramids, an edgeedge with one FLiFe3 tetrahedra, and an edgeedge with one FLiFe3 trigonal pyramid. In the eleventh F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+ and two Fe2+ atoms. In the twelfth F1- site, F1- is bonded in a trigonal planar geometry to one Li1+ and two Fe2+ atoms. In the thirteenth F1- site, F1- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Fe2+ atoms. In the fourteenth F1- site, F1- is bonded to two Li1+ and two Fe2+ atoms to form distorted FLi2Fe2 tetrahedra that share a cornercorner with one OLiFe3 tetrahedra, corners with two FLiFe3 tetrahedra, corners with three FLi2Fe2 trigonal pyramids, an edgeedge with one OLiFe3 tetrahedra, and an edgeedge with one FLi2Fe2 tetrahedra. In the fifteenth F1- site, F1- is bonded to two Li1+ and two Fe2+ atoms to form FLi2Fe2 tetrahedra that share a cornercorner with one OLiFe3 tetrahedra, corners with two FLiFe3 tetrahedra, corners with four FLi2Fe2 trigonal pyramids, and an edgeedge with one FLi2Fe2 tetrahedra. In the sixteenth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom.