DOI: 10.17188/1271645
title: Materials Data on La4Ti9(Si2O15)2 by Materials Project

description: La4Ti9(Si2O15)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.48–2.76 Å. In the second La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.47–2.68 Å. There are four inequivalent Ti+3.56+ sites. In the first Ti+3.56+ site, Ti+3.56+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 46–49°. There are a spread of Ti–O bond distances ranging from 1.92–2.16 Å. In the second Ti+3.56+ site, Ti+3.56+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of Ti–O bond distances ranging from 1.86–2.28 Å. In the third Ti+3.56+ site, Ti+3.56+ 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 46–48°. There are a spread of Ti–O bond distances ranging from 1.87–2.26 Å. In the fourth Ti+3.56+ site, Ti+3.56+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six SiO4 tetrahedra. There are two shorter (1.94 Å) and four longer (2.13 Å) Ti–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three TiO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–54°. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent TiO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two La3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two La3+, one Ti+3.56+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one La3+ and three Ti+3.56+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti+3.56+ atoms. In the sixth O2- site, O2- is bonded in a distorted see-saw-like geometry to two La3+ and two Ti+3.56+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two La3+, one Ti+3.56+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one La3+ and three Ti+3.56+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti+3.56+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti+3.56+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti+3.56+ atoms.