Materials Data on Ba4Sb2O9 by Materials Project

Abstract

Ba4Sb2O9 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to nine O2- atoms. There are three shorter (2.86 Å) and six longer (3.07 Å) Ba–O bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ba–O bond lengths are 2.61 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra and faces with six equivalent SbO6 octahedra. There are six shorter (2.99 Å) and six longer (3.06 Å) Ba–O bond lengths. Sb5+ is bonded to six O2- atoms to form distorted SbO6 octahedra that share faces with three equivalent BaO12 cuboctahedra and a faceface with one SbO6 octahedra. There are three shorter (1.94 Å) and three longer (2.15 Å) Sb–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+ and one Sb5+ atom. In the second O2- site, O2- is bonded to four Ba2+ and two equivalent Sb5+ atoms to form a mixture of distorted corner and face-sharing OBa4Sb2 octahedra. The corner-sharing octahedra tilt angles range from 8–60°.