Materials Data on Ba2Sb2O7 by Materials Project
Ba2Sb2O7 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to eight O2- atoms to form BaO8 hexagonal bipyramids that share corners with two equivalent BaO8 hexagonal bipyramids, corners with two equivalent SbO6 octahedra, edges with four equivalent BaO8 hexagonal bipyramids, and edges with six SbO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Ba–O bond distances ranging from 2.55–2.96 Å. In the second Ba2+ site, Ba2+ is bonded to eight O2- atoms to form distorted BaO8 hexagonal bipyramids that share edges with six BaO8 hexagonal bipyramids and edges with six SbO6 octahedra. There are four shorter (2.64 Å) and four longer (3.00 Å) Ba–O bond lengths. There are two inequivalent Sb5+ sites. In the first Sb5+ site, Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with six SbO6 octahedra and edges with six BaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 40–43°. There are four shorter (2.03 Å) and two longer (2.10 Å) Sb–O bond lengths. In the second Sb5+ site, Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent BaO8 hexagonal bipyramids, corners with four equivalent SbO6 octahedra, and edges with six BaO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. There are two shorter (1.93 Å) and four longer (2.10 Å) Sb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+ and two Sb5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+ and two equivalent Sb5+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Sb5+ atom.