Materials Data on Ba3CuRu2O9 by Materials Project
Ba3CuRu2O9 crystallizes in the orthorhombic Cmcm 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 distorted BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, faces with three equivalent CuO6 octahedra, and faces with four equivalent RuO6 octahedra. The corner-sharing octahedra tilt angles range from 7–9°. There are a spread of Ba–O bond distances ranging from 2.84–3.24 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 equivalent BaO12 cuboctahedra, faces with two equivalent CuO6 octahedra, and faces with six equivalent RuO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.85–3.06 Å. Ru5+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent CuO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedra tilt angles range from 3–12°. There are a spread of Ru–O bond distances ranging from 1.90–2.10 Å. Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with six equivalent RuO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–12°. There are four shorter (2.03 Å) and two longer (2.35 Å) Cu–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+, one Ru5+, and one Cu2+ atom. In the second O2- site, O2- is bonded to four Ba2+ and two equivalent Ru5+ atoms to form distorted corner-sharing OBa4Ru2 octahedra. The corner-sharing octahedral tilt angles are 6°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two equivalent Ru5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+, one Ru5+, and one Cu2+ atom.