Materials Data on LiFe2OF3 by Materials Project
LiFe2OF3 is Spinel-derived structured and crystallizes in the tetragonal P4_3 space group. The structure is three-dimensional. Li1+ is bonded to one O2- and five F1- atoms to form LiOF5 octahedra that share corners with six equivalent FeOF3 tetrahedra, edges with two equivalent LiOF5 octahedra, and edges with four equivalent FeO2F4 octahedra. The Li–O bond length is 2.01 Å. There are a spread of Li–F bond distances ranging from 2.06–2.21 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to two equivalent O2- and four F1- atoms to form FeO2F4 octahedra that share corners with six equivalent FeOF3 tetrahedra, edges with two equivalent FeO2F4 octahedra, and edges with four equivalent LiOF5 octahedra. There are one shorter (1.99 Å) and one longer (2.07 Å) Fe–O bond lengths. There are a spread of Fe–F bond distances ranging from 2.15–2.27 Å. In the second Fe2+ site, Fe2+ is bonded to one O2- and three F1- atoms to form FeOF3 tetrahedra that share corners with six equivalent LiOF5 octahedra and corners with six equivalent FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 51–68°. The Fe–O bond length is 1.89 Å. There are a spread of Fe–F bond distances ranging from 2.01–2.13 Å. O2- is bonded to one Li1+ and three Fe2+ atoms to form distorted corner-sharing OLiFe3 tetrahedra. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Fe2+ atoms. In the second F1- site, F1- is bonded in a rectangular see-saw-like geometry to two equivalent Li1+ and two Fe2+ atoms. In the third F1- site, F1- is bonded in a rectangular see-saw-like geometry to two equivalent Li1+ and two Fe2+ atoms.