DOI: 10.17188/1298786
title: Materials Data on Li4Ti4Cr(Fe2O9)2 by Materials Project

description: Li4Ti4Cr(Fe2O9)2 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share corners with two equivalent CrO6 octahedra, corners with three equivalent TiO6 octahedra, an edgeedge with one TiO6 octahedra, an edgeedge with one CrO6 octahedra, edges with two equivalent FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 12–77°. There are a spread of Li–O bond distances ranging from 2.12–2.33 Å. In the second Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.18–2.63 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three equivalent LiO5 trigonal bipyramids, edges with four TiO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ti–O bond distances ranging from 1.91–2.10 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent FeO5 square pyramids and edges with four TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.93–2.04 Å. Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent LiO5 trigonal bipyramids, edges with two equivalent CrO6 octahedra, edges with four equivalent FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. There is two shorter (1.92 Å) and four longer (1.98 Å) Cr–O bond length. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five O2- atoms to form FeO5 square pyramids that share corners with two equivalent FeO6 octahedra, corners with four equivalent TiO6 octahedra, and edges with two equivalent FeO5 square pyramids. The corner-sharing octahedra tilt angles range from 48–68°. There are a spread of Fe–O bond distances ranging from 1.96–2.03 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent FeO5 square pyramids, edges with two equivalent CrO6 octahedra, edges with two equivalent FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of Fe–O bond distances ranging from 2.00–2.11 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Li1+, two equivalent Cr4+, and one Fe3+ atom to form OLi2Cr2Fe square pyramids that share corners with two equivalent OLi2Cr2Fe square pyramids, a cornercorner with one OLi2Fe3 trigonal bipyramid, and edges with three equivalent OLi2Cr2Fe square pyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ti4+ and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two Li1+, one Ti4+, and two equivalent Fe3+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Cr4+ and two equivalent Fe3+ atoms. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent Ti4+ atoms. In the seventh O2- site, O2- is bonded to two equivalent Li1+ and three Ti4+ atoms to form distorted OLi2Ti3 trigonal bipyramids that share corners with two equivalent OLi2Fe3 trigonal bipyramids and edges with three OLi2Ti3 trigonal bipyramids. In the eighth O2- site, O2- is bonded to two equivalent Li1+ and three Fe3+ atoms to form distorted OLi2Fe3 trigonal bipyramids that share a cornercorner with one OLi2Cr2Fe square pyramid, corners with two equivalent OLi2Ti3 trigonal bipyramids, and edges with three OLi2Ti3 trigonal bipyramids. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, two equivalent Ti4+, and one Fe3+ atom.