Materials Data on Ba3YIr2O9 by Materials Project
Ba3YIr2O9 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are three 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 BaO12 cuboctahedra, faces with three equivalent YO6 octahedra, and faces with five IrO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.98–3.12 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent IrO6 octahedra, faces with seven BaO12 cuboctahedra, faces with three equivalent YO6 octahedra, and faces with four IrO6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are a spread of Ba–O bond distances ranging from 2.85–3.37 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent YO6 octahedra, faces with seven BaO12 cuboctahedra, a faceface with one YO6 octahedra, and faces with six IrO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Ba–O bond distances ranging from 2.73–3.20 Å. Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent IrO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one IrO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are three shorter (2.17 Å) and three longer (2.30 Å) Y–O bond lengths. There are two inequivalent Ir+4.50+ sites. In the first Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with three equivalent YO6 octahedra, corners with three equivalent IrO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are three shorter (1.97 Å) and three longer (2.04 Å) Ir–O bond lengths. In the second Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent IrO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one YO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.00 Å) and three longer (2.06 Å) Ir–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Y3+, and one Ir+4.50+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two Ir+4.50+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+, one Y3+, and one Ir+4.50+ atom.