DOI: 10.17188/1740362
title: Materials Data on LiFe7O7F by Materials Project

description: LiFe7O7F crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Li1+ is bonded to two O2- and three equivalent F1- atoms to form LiO2F3 trigonal bipyramids that share corners with two FeO5 trigonal bipyramids, corners with six equivalent LiO2F3 trigonal bipyramids, and edges with six FeO4F trigonal bipyramids. There are one shorter (2.11 Å) and one longer (2.14 Å) Li–O bond lengths. There are two shorter (2.07 Å) and one longer (2.09 Å) Li–F bond lengths. There are seven inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing FeO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.03–2.26 Å. In the second Fe2+ site, Fe2+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share a cornercorner with one LiO2F3 trigonal bipyramid, corners with seven FeO5 trigonal bipyramids, and edges with six FeO4F trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.03–2.27 Å. In the third Fe2+ site, Fe2+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share a cornercorner with one LiO2F3 trigonal bipyramid, corners with seven FeO5 trigonal bipyramids, and edges with six FeO4F trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.04–2.24 Å. In the fourth Fe2+ site, Fe2+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with eight FeO4F trigonal bipyramids and edges with six FeO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.01–2.25 Å. In the fifth Fe2+ site, Fe2+ is bonded to four O2- and one F1- atom to form FeO4F trigonal bipyramids that share corners with eight FeO4F trigonal bipyramids, edges with three equivalent LiO2F3 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.07–2.15 Å. The Fe–F bond length is 2.19 Å. In the sixth Fe2+ site, Fe2+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing FeO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.01–2.27 Å. In the seventh Fe2+ site, Fe2+ is bonded to four O2- and one F1- atom to form FeO4F trigonal bipyramids that share corners with eight FeO4F trigonal bipyramids, edges with three equivalent LiO2F3 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 2.00–2.21 Å. The Fe–F bond length is 2.24 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to one Li1+ and four Fe2+ atoms to form OLiFe4 trigonal bipyramids that share corners with eight OLiFe4 trigonal bipyramids, edges with three equivalent OFe5 trigonal bipyramids, and edges with three equivalent FLi3Fe2 trigonal bipyramids. In the second O2- site, O2- is bonded to five Fe2+ atoms to form OFe5 trigonal bipyramids that share corners with eight OLiFe4 trigonal bipyramids and edges with six OFe5 trigonal bipyramids. In the third O2- site, O2- is bonded to one Li1+ and four Fe2+ atoms to form OLiFe4 trigonal bipyramids that share corners with eight OLiFe4 trigonal bipyramids, edges with three equivalent OFe5 trigonal bipyramids, and edges with three equivalent FLi3Fe2 trigonal bipyramids. In the fourth O2- site, O2- is bonded to five Fe2+ atoms to form a mixture of edge and corner-sharing OFe5 trigonal bipyramids. In the fifth O2- site, O2- is bonded to five Fe2+ atoms to form a mixture of edge and corner-sharing OFe5 trigonal bipyramids. In the sixth O2- site, O2- is bonded to five Fe2+ atoms to form OFe5 trigonal bipyramids that share a cornercorner with one FLi3Fe2 trigonal bipyramid, corners with seven OFe5 trigonal bipyramids, and edges with six OLiFe4 trigonal bipyramids. In the seventh O2- site, O2- is bonded to five Fe2+ atoms to form OFe5 trigonal bipyramids that share a cornercorner with one FLi3Fe2 trigonal bipyramid, corners with seven OFe5 trigonal bipyramids, and edges with six OLiFe4 trigonal bipyramids. F1- is bonded to three equivalent Li1+ and two Fe2+ atoms to form FLi3Fe2 trigonal bipyramids that share corners with two OFe5 trigonal bipyramids, corners with six equivalent FLi3Fe2 trigonal bipyramids, and edges with six OLiFe4 trigonal bipyramids.