DOI: 10.17188/1299256
title: Materials Data on Li2CrFe3O8 by Materials Project

description: Li2CrFe3O8 is Spinel-derived structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent CrO6 octahedra and corners with nine FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–63°. There are a spread of Li–O bond distances ranging from 1.97–2.00 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with three equivalent CrO6 octahedra, corners with three FeO6 octahedra, and edges with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 61–64°. There is one shorter (1.80 Å) and three longer (1.95 Å) Li–O bond length. Cr5+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six FeO6 octahedra, corners with three equivalent LiO4 tetrahedra, corners with three equivalent LiO4 trigonal pyramids, and edges with three FeO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Cr–O bond distances ranging from 2.02–2.06 Å. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one CrO6 octahedra, edges with four FeO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.96–2.04 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one CrO6 octahedra, edges with four FeO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.97–2.04 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one CrO6 octahedra, edges with four FeO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.96–2.04 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr5+, and two Fe3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr5+, and two Fe3+ atoms. In the third O2- site, O2- is bonded to one Li1+, one Cr5+, and two Fe3+ atoms to form distorted OLiCrFe2 tetrahedra that share corners with four OLiFe3 tetrahedra, a cornercorner with one OLiFe3 trigonal pyramid, edges with two OLiCrFe2 tetrahedra, and an edgeedge with one OLiFe3 trigonal pyramid. In the fourth O2- site, O2- is bonded to one Li1+ and three Fe3+ atoms to form a mixture of distorted corner and edge-sharing OLiFe3 trigonal pyramids. In the fifth O2- site, O2- is bonded to one Li1+ and three Fe3+ atoms to form distorted OLiFe3 tetrahedra that share corners with six OLiCrFe2 tetrahedra and corners with three equivalent OLiFe3 trigonal pyramids. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr5+, and two Fe3+ atoms. In the seventh O2- site, O2- is bonded to one Li1+, one Cr5+, and two Fe3+ atoms to form distorted OLiCrFe2 tetrahedra that share corners with four OLiCrFe2 tetrahedra, a cornercorner with one OLiFe3 trigonal pyramid, edges with two OLiCrFe2 tetrahedra, and an edgeedge with one OLiFe3 trigonal pyramid. In the eighth O2- site, O2- is bonded to one Li1+, one Cr5+, and two Fe3+ atoms to form distorted OLiCrFe2 tetrahedra that share corners with four OLiCrFe2 tetrahedra, a cornercorner with one OLiFe3 trigonal pyramid, edges with two OLiCrFe2 tetrahedra, and an edgeedge with one OLiFe3 trigonal pyramid.