DOI: 10.17188/1731688
title: Materials Data on Ba4Ti6Si4O25 by Materials Project

description: Ba4Ti6Si4O25 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are two inequivalent Ba sites. In the first Ba site, Ba is bonded in a 11-coordinate geometry to eleven O atoms. There are a spread of Ba–O bond distances ranging from 2.65–3.20 Å. In the second Ba site, Ba is bonded in a 11-coordinate geometry to eleven O atoms. There are a spread of Ba–O bond distances ranging from 2.65–3.30 Å. There are four inequivalent Ti sites. In the first Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with two equivalent SiO4 tetrahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Ti–O bond distances ranging from 1.92–2.05 Å. In the second Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with two equivalent SiO4 tetrahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Ti–O bond distances ranging from 1.94–2.05 Å. In the third Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with two TiO6 octahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Ti–O bond distances ranging from 1.83–2.13 Å. In the fourth Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with two TiO6 octahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Ti–O bond distances ranging from 1.83–2.10 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two TiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent TiO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There is two shorter (1.62 Å) and two longer (1.65 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent TiO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There is two shorter (1.62 Å) and two longer (1.65 Å) Si–O bond length. There are thirteen inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent Ba and two Si atoms. In the second O site, O is bonded in a 2-coordinate geometry to two Ba, one Ti, and one Si atom. In the third O site, O is bonded in a distorted bent 120 degrees geometry to two Ba, one Ti, and one Si atom. In the fourth O site, O is bonded in a 4-coordinate geometry to two equivalent Ba and two equivalent Ti atoms. In the fifth O site, O is bonded in a distorted T-shaped geometry to one Ba and two equivalent Ti atoms. In the sixth O site, O is bonded in a distorted trigonal planar geometry to one Ba and three Ti atoms. In the seventh O site, O is bonded in a 2-coordinate geometry to two equivalent Ba, one Ti, and one Si atom. In the eighth O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent Ba and two Si atoms. In the ninth O site, O is bonded in a 2-coordinate geometry to two equivalent Ba, one Ti, and one Si atom. In the tenth O site, O is bonded in a rectangular see-saw-like geometry to four Ba atoms. In the eleventh O site, O is bonded in a distorted T-shaped geometry to one Ba and two equivalent Ti atoms. In the twelfth O site, O is bonded in a distorted trigonal planar geometry to one Ba and three Ti atoms. In the thirteenth O site, O is bonded in a 4-coordinate geometry to two equivalent Ba and two equivalent Ti atoms.