DOI: 10.17188/1747327
title: Materials Data on Li4Ti4Fe4CoO18 by Materials Project

description: Li4Ti4Fe4CoO18 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 CoO6 octahedra, corners with three equivalent TiO6 octahedra, an edgeedge with one TiO6 octahedra, an edgeedge with one CoO6 octahedra, edges with two equivalent FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 17–77°. There are a spread of Li–O bond distances ranging from 2.09–2.35 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 2.17–2.67 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 48°. There are a spread of Ti–O bond distances ranging from 1.90–2.10 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 1.96–2.03 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five O2- atoms to form distorted 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 51–68°. There are a spread of Fe–O bond distances ranging from 1.94–2.06 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 FeO6 octahedra, edges with two equivalent CoO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 48°. There are a spread of Fe–O bond distances ranging from 1.93–2.02 Å. Co4+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent LiO5 trigonal bipyramids, edges with two equivalent CoO6 octahedra, edges with four equivalent FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. There is two shorter (1.90 Å) and four longer (1.95 Å) Co–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Li1+, one Fe3+, and two equivalent Co4+ atoms to form a mixture of corner and edge-sharing OLi2FeCo2 square pyramids. In the second O2- site, O2- is bonded in a 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 4-coordinate geometry to two Li1+, one Ti4+, and two equivalent Fe3+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Fe3+ and one Co4+ atom. 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 four equivalent OLiTi2Fe tetrahedra and edges with two equivalent OLi2Ti3 trigonal bipyramids. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Fe3+ atoms. In the ninth O2- site, O2- is bonded to one Li1+, two equivalent Ti4+, and one Fe3+ atom to form distorted OLiTi2Fe tetrahedra that share corners with two equivalent OLiTi2Fe tetrahedra and corners with four equivalent OLi2Ti3 trigonal bipyramids.