Materials Data on Li4FeO3F by Materials Project
Li4FeO3F crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form LiO3F tetrahedra that share corners with four equivalent FeO3F tetrahedra, corners with six LiO3F tetrahedra, and edges with three LiO3F tetrahedra. There are a spread of Li–O bond distances ranging from 1.92–1.95 Å. The Li–F bond length is 2.04 Å. In the second Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F tetrahedra that share corners with four equivalent FeO3F tetrahedra, corners with six LiO3F tetrahedra, and edges with three LiO3F tetrahedra. There are a spread of Li–O bond distances ranging from 1.97–2.07 Å. The Li–F bond length is 2.10 Å. Fe3+ is bonded to three O2- and one F1- atom to form FeO3F tetrahedra that share corners with sixteen LiO3F tetrahedra. All Fe–O bond lengths are 1.87 Å. The Fe–F bond length is 2.12 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four Li1+ and one Fe3+ atom to form distorted corner-sharing OLi4Fe trigonal bipyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to four Li1+ and one Fe3+ atom. F1- is bonded in a 5-coordinate geometry to four Li1+ and one Fe3+ atom.