DOI: 10.17188/1305706
title: Materials Data on Li2FeF4 by Materials Project

description: Li2FeF4 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are eight inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with five FeF6 octahedra, corners with three LiF4 tetrahedra, and a cornercorner with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 16–71°. There are a spread of Li–F bond distances ranging from 1.84–1.90 Å. In the second Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with four FeF6 octahedra, corners with two LiF4 tetrahedra, corners with two equivalent LiF4 trigonal pyramids, and an edgeedge with one FeF6 octahedra. The corner-sharing octahedra tilt angles range from 49–65°. There are a spread of Li–F bond distances ranging from 1.84–1.95 Å. In the third Li1+ site, Li1+ is bonded to four F1- atoms to form distorted LiF4 trigonal pyramids that share corners with three FeF6 octahedra, corners with four LiF4 tetrahedra, and edges with two FeF6 octahedra. The corner-sharing octahedra tilt angles range from 52–64°. There are a spread of Li–F bond distances ranging from 1.84–2.00 Å. In the fourth Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with four FeF6 octahedra, corners with three LiF4 tetrahedra, a cornercorner with one LiF4 trigonal pyramid, and an edgeedge with one FeF6 octahedra. The corner-sharing octahedra tilt angles range from 52–83°. There are a spread of Li–F bond distances ranging from 1.84–1.95 Å. In the fifth Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with four FeF6 octahedra, corners with three LiF4 tetrahedra, a cornercorner with one LiF4 trigonal pyramid, and an edgeedge with one FeF6 octahedra. The corner-sharing octahedra tilt angles range from 52–83°. There are a spread of Li–F bond distances ranging from 1.84–1.95 Å. In the sixth Li1+ site, Li1+ is bonded to four F1- atoms to form distorted LiF4 trigonal pyramids that share corners with three FeF6 octahedra, corners with four LiF4 tetrahedra, and edges with two FeF6 octahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Li–F bond distances ranging from 1.84–1.99 Å. In the seventh Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with four FeF6 octahedra, corners with two LiF4 tetrahedra, corners with two equivalent LiF4 trigonal pyramids, and an edgeedge with one FeF6 octahedra. The corner-sharing octahedra tilt angles range from 49–65°. There are a spread of Li–F bond distances ranging from 1.84–1.94 Å. In the eighth Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with five FeF6 octahedra, corners with three LiF4 tetrahedra, and a cornercorner with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 16–71°. There are a spread of Li–F bond distances ranging from 1.84–1.89 Å. There are four inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share corners with four FeF6 octahedra, corners with eight LiF4 tetrahedra, corners with two LiF4 trigonal pyramids, and an edgeedge with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 40–64°. There are a spread of Fe–F bond distances ranging from 2.01–2.42 Å. In the second Fe2+ site, Fe2+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share corners with four FeF6 octahedra, corners with five LiF4 tetrahedra, a cornercorner with one LiF4 trigonal pyramid, edges with two LiF4 tetrahedra, and an edgeedge with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 40–64°. There are a spread of Fe–F bond distances ranging from 1.99–2.46 Å. In the third Fe2+ site, Fe2+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share corners with four FeF6 octahedra, corners with five LiF4 tetrahedra, a cornercorner with one LiF4 trigonal pyramid, edges with two LiF4 tetrahedra, and an edgeedge with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 40–64°. There are a spread of Fe–F bond distances ranging from 1.99–2.45 Å. In the fourth Fe2+ site, Fe2+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share corners with four FeF6 octahedra, corners with eight LiF4 tetrahedra, corners with two LiF4 trigonal pyramids, and an edgeedge with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 40–64°. There are a spread of Fe–F bond distances ranging from 2.01–2.43 Å. There are sixteen inequivalent F1- sites. In the first F1- site, F1- is bonded in a trigonal planar geometry to two Li1+ and one Fe2+ atom. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom. 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 in a distorted trigonal pyramidal geometry to two Li1+ and two Fe2+ atoms. In the fifth F1- site, F1- is bonded in a distorted T-shaped geometry to two Li1+ and one Fe2+ atom. In the sixth F1- site, F1- is bonded in a 4-coordinate geometry to two Li1+ and two Fe2+ atoms. In the seventh F1- site, F1- is bonded in a 4-coordinate geometry to two Li1+ and two Fe2+ atoms. In the eighth F1- site, F1- is bonded in a rectangular see-saw-like geometry to two Li1+ and two Fe2+ atoms. In the ninth F1- site, F1- is bonded in a rectangular see-saw-like geometry to two Li1+ and two Fe2+ atoms. In the tenth F1- site, F1- is bonded in a 4-coordinate geometry to two Li1+ and two Fe2+ atoms. In the eleventh F1- site, F1- is bonded in a 4-coordinate geometry to two Li1+ and two Fe2+ atoms. In the twelfth F1- site, F1- is bonded in a distorted T-shaped geometry to two Li1+ and one Fe2+ atom. In the thirteenth F1- site, F1- is bonded in a distorted trigonal pyramidal geometry to two Li1+ and two Fe2+ atoms. In the fourteenth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom. In the fifteenth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom. In the sixteenth F1- site, F1- is bonded in a trigonal planar geometry to two Li1+ and one Fe2+ atom.