Materials Data on LiFe2O2F3 by Materials Project

Abstract

LiFe2O2F3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Li1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Li–F bond distances ranging from 1.94–2.40 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five O2- and one F1- atom to form a mixture of distorted corner and edge-sharing FeO5F octahedra. The corner-sharing octahedra tilt angles range from 21–39°. There are a spread of Fe–O bond distances ranging from 1.95–2.12 Å. The Fe–F bond length is 2.38 Å. In the second Fe3+ site, Fe3+ is bonded to two O2- and four F1- atoms to form a mixture of distorted corner and edge-sharing FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 21–33°. There are one shorter (1.93 Å) and one longer (2.11 Å) Fe–O bond lengths. There are a spread of Fe–F bond distances ranging from 1.93–2.01 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to three Fe3+ atoms. In the second O2- site, O2- is bonded to four Fe3+ atoms to form distorted OFe4 trigonal pyramids that share a cornercorner with one FLi3Fe trigonal pyramid, corners with two equivalent OFe4 trigonal pyramids, and edges with two equivalent OFe4 trigonal pyramids. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted T-shaped geometry to two equivalent Li1+ and one Fe3+ atom. In the second F1- site, F1- is bonded to three equivalent Li1+ and one Fe3+ atom to form distorted FLi3Fe trigonal pyramids that share a cornercorner with one OFe4 trigonal pyramid, corners with two equivalent FLi3Fe trigonal pyramids, and edges with two equivalent FLi3Fe trigonal pyramids. In the third F1- site, F1- is bonded in a 4-coordinate geometry to one Li1+ and three Fe3+ atoms.