Materials Data on Ba3Sr4O7 by Materials Project

Abstract

Ba3Sr4O7 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six O2- atoms to form BaO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four BaO6 octahedra, edges with three BaO6 octahedra, and edges with nine SrO6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Ba–O bond distances ranging from 2.69–2.81 Å. In the second Ba2+ site, Ba2+ is bonded to six O2- atoms to form BaO6 octahedra that share corners with six BaO6 octahedra, edges with four BaO6 octahedra, and edges with eight equivalent SrO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.70 Å) and four longer (2.74 Å) Ba–O bond lengths. There are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent BaO6 octahedra, corners with four SrO6 octahedra, edges with five equivalent BaO6 octahedra, and edges with seven SrO6 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. There are a spread of Sr–O bond distances ranging from 2.53–2.76 Å. In the second Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with six SrO6 octahedra, edges with four SrO6 octahedra, and edges with eight BaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are two shorter (2.64 Å) and four longer (2.70 Å) Sr–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ba2+ and four Sr2+ atoms to form a mixture of corner and edge-sharing OBa2Sr4 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the second O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent Sr2+ atoms to form a mixture of corner and edge-sharing OBa2Sr4 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent Sr2+ atoms to form a mixture of corner and edge-sharing OBa2Sr4 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. In the fourth O2- site, O2- is bonded to four Ba2+ and two equivalent Sr2+ atoms to form a mixture of corner and edge-sharing OBa4Sr2 octahedra. The corner-sharing octahedra tilt angles range from 0–2°.