Materials Data on Li2Ti7O15 by Materials Project
Li2Ti7O15 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with eight TiO6 octahedra and corners with two equivalent LiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–70°. There are a spread of Li–O bond distances ranging from 1.86–1.96 Å. There are four inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with three equivalent LiO4 tetrahedra, and edges with four equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Ti–O bond distances ranging from 1.89–2.09 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with three equivalent LiO4 tetrahedra, and edges with four equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Ti–O bond distances ranging from 1.96–2.12 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with six TiO6 octahedra, corners with two equivalent LiO4 tetrahedra, and edges with three equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–53°. There are a spread of Ti–O bond distances ranging from 1.70–2.33 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There is two shorter (1.99 Å) and four longer (2.00 Å) Ti–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti4+ atoms. In the second O2- site, O2- is bonded to one Li1+ and three equivalent Ti4+ atoms to form a mixture of distorted corner and edge-sharing OLiTi3 tetrahedra. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti4+ atoms. In the fourth O2- site, O2- is bonded to one Li1+ and three equivalent Ti4+ atoms to form a mixture of distorted corner and edge-sharing OLiTi3 tetrahedra. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti4+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti4+ atoms. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Li1+ and one Ti4+ atom. In the eighth O2- site, O2- is bonded in a square co-planar geometry to four equivalent Ti4+ atoms.