Materials Data on LiFe5(OF2)4 by Materials Project

Abstract

LiFe5(OF2)4 is zeta iron carbide-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share corners with eight equivalent FeO2F4 octahedra and edges with two equivalent FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 44–53°. There are two shorter (2.00 Å) and four longer (2.03 Å) Li–F bond lengths. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to two equivalent O2- and four F1- atoms to form FeO2F4 octahedra that share corners with eight FeO4F2 octahedra, an edgeedge with one LiF6 octahedra, and an edgeedge with one FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 47–51°. Both Fe–O bond lengths are 1.93 Å. There are two shorter (2.00 Å) and two longer (2.09 Å) Fe–F bond lengths. In the second Fe3+ site, Fe3+ is bonded to four equivalent O2- and two equivalent F1- atoms to form a mixture of edge and corner-sharing FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 47–51°. All Fe–O bond lengths are 2.01 Å. Both Fe–F bond lengths are 2.11 Å. In the third Fe3+ site, Fe3+ is bonded to two equivalent O2- and four F1- atoms to form FeO2F4 octahedra that share corners with four equivalent LiF6 octahedra, corners with four equivalent FeO2F4 octahedra, and edges with two FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 44–53°. Both Fe–O bond lengths are 1.93 Å. There are two shorter (2.05 Å) and two longer (2.06 Å) Fe–F bond lengths. O2- is bonded in a distorted trigonal planar geometry to three Fe3+ atoms. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to three Fe3+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two Fe3+ atoms. In the third F1- site, F1- is bonded in a trigonal planar geometry to one Li1+ and two equivalent Fe3+ atoms.