Materials Data on Ba2SrTi3O9 by Materials Project

Abstract

Ba2SrTi3O9 crystallizes in the orthorhombic Cmm2 space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with five equivalent SrO12 cuboctahedra, corners with seven equivalent BaO12 cuboctahedra, faces with two equivalent SrO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight TiO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.81–2.95 Å. Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with two equivalent SrO12 cuboctahedra, corners with ten equivalent BaO12 cuboctahedra, faces with two equivalent SrO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight TiO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.75–2.93 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 six TiO6 octahedra, faces with two equivalent SrO12 cuboctahedra, and faces with six equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Ti–O bond distances ranging from 1.85–2.25 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, faces with four equivalent BaO12 cuboctahedra, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are a spread of Ti–O bond distances ranging from 1.84–2.25 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to three equivalent Ba2+, one Sr2+, and two equivalent Ti4+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent Sr2+, and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, two equivalent Sr2+, and two Ti4+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Ti4+ atoms.