Materials Data on Ba4Ti12O27 by Materials Project
Ba4Ti12O27 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Ba–O bond distances ranging from 2.81–3.21 Å. In the second Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to eleven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–2.95 Å. In the third Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.73–3.20 Å. There are ten inequivalent Ti+3.83+ sites. In the first Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent TiO6 octahedra and corners with two equivalent TiO5 square pyramids. The corner-sharing octahedral tilt angles are 6°. There are two shorter (2.03 Å) and four longer (2.05 Å) Ti–O bond lengths. In the second Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 16°. There is two shorter (1.97 Å) and four longer (2.00 Å) Ti–O bond length. In the third Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent TiO5 square pyramids, and edges with four TiO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are four shorter (1.99 Å) and two longer (2.01 Å) Ti–O bond lengths. In the fourth Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent TiO5 square pyramids, and edges with three TiO6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are a spread of Ti–O bond distances ranging from 1.92–2.08 Å. In the fifth Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 16–52°. There are a spread of Ti–O bond distances ranging from 1.86–2.17 Å. In the sixth Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, edges with four TiO6 octahedra, and an edgeedge with one TiO5 square pyramid. The corner-sharing octahedral tilt angles are 55°. There are a spread of Ti–O bond distances ranging from 1.94–2.09 Å. In the seventh Ti+3.83+ site, Ti+3.83+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing TiO5 square pyramids. The corner-sharing octahedra tilt angles range from 3–30°. There are a spread of Ti–O bond distances ranging from 1.82–2.04 Å. In the eighth Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 6–47°. There are a spread of Ti–O bond distances ranging from 1.89–2.16 Å. In the ninth Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–O bond distances ranging from 1.89–2.15 Å. In the tenth Ti+3.83+ site, Ti+3.83+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 40–53°. There are a spread of Ti–O bond distances ranging from 1.84–2.18 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted see-saw-like geometry to four Ti+3.83+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti+3.83+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Ti+3.83+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Ti+3.83+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three Ba2+ and two Ti+3.83+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two Ti+3.83+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Ba2+ and three Ti+3.83+ atoms. In the eighth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two Ti+3.83+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Ti+3.83+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+ and two Ti+3.83+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti+3.83+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to three Ba2+ and two Ti+3.83+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Ti+3.83+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+ and two Ti+3.83+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted T-shaped geometry to two Ba2+ and three Ti+3.83+ atoms. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Ti+3.83+ atoms.