Materials Data on Fe4O3F5 by Materials Project

Abstract

Fe4O3F5 is zeta iron carbide-derived structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are three inequivalent Fe+2.75+ sites. In the first Fe+2.75+ site, Fe+2.75+ is bonded to two equivalent O2- and four equivalent F1- atoms to form FeO2F4 octahedra that share corners with eight equivalent FeO3F3 octahedra and edges with two equivalent FeOF5 octahedra. The corner-sharing octahedra tilt angles range from 45–51°. Both Fe–O bond lengths are 1.94 Å. All Fe–F bond lengths are 2.04 Å. In the second Fe+2.75+ site, Fe+2.75+ is bonded to one O2- and five F1- atoms to form FeOF5 octahedra that share corners with eight equivalent FeO3F3 octahedra and edges with two equivalent FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 48–57°. The Fe–O bond length is 1.97 Å. There are one shorter (2.05 Å) and four longer (2.15 Å) Fe–F bond lengths. In the third Fe+2.75+ site, Fe+2.75+ is bonded to three O2- and three F1- atoms to form FeO3F3 octahedra that share corners with eight FeO2F4 octahedra and edges with two equivalent FeO3F3 octahedra. The corner-sharing octahedra tilt angles range from 45–57°. There are a spread of Fe–O bond distances ranging from 1.93–1.99 Å. There are two shorter (2.10 Å) and one longer (2.17 Å) Fe–F bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Fe+2.75+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Fe+2.75+ atoms. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to three Fe+2.75+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to three Fe+2.75+ atoms.