Materials Data on Ba3BeIr2O9 by Materials Project

Abstract

Ba3BeIr2O9 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six equivalent BaO12 cuboctahedra, faces with two equivalent BeO6 octahedra, and faces with six equivalent IrO6 octahedra. All Ba–O bond lengths are 2.83 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with three equivalent BeO6 octahedra, and faces with five equivalent IrO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.81–2.85 Å. Be2+ is bonded to six equivalent O2- atoms to form BeO6 octahedra that share corners with six equivalent IrO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. All Be–O bond lengths are 1.99 Å. Ir5+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with three equivalent BeO6 octahedra, corners with three equivalent IrO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are three shorter (1.99 Å) and three longer (2.04 Å) Ir–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Be2+, and one Ir5+ atom. In the second O2- site, O2- is bonded to four Ba2+ and two equivalent Ir5+ atoms to form a mixture of distorted face and corner-sharing OBa4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 0–60°.