Ba3CoIr2O9 is (Cubic) Perovskite-derived structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent O(1) and nine equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(2)O12 cuboctahedra, corners with six equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ir(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Co(1)O6 octahedra, and faces with four equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Co(1)O6 octahedra, and faces with six equivalent Ir(1)O6 octahedra. Ir(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form IrO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Co(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 2°. Co(1) is bonded to six equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Ir(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ir(1) atoms to form a mixture of distorted corner and face-sharing OBa4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 6-60°. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Ir(1), and one Co(1) atom.
Ba3CoIr2O9 is (Cubic) Perovskite-derived structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent O(1) and nine equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(2)O12 cuboctahedra, corners with six equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ir(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Co(1)O6 octahedra, and faces with four equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 10°. All Ba(1)-O(1) bond lengths are 2.98 Å. There are six shorter (2.93 Å) and three longer (2.96 Å) Ba(1)-O(2) bond lengths. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Co(1)O6 octahedra, and faces with six equivalent Ir(1)O6 octahedra. All Ba(2)-O(1) bond lengths are 2.93 Å. All Ba(2)-O(2) bond lengths are 2.98 Å. Ir(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form IrO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Co(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Ir(1)-O(1) bond lengths are 2.07 Å. All Ir(1)-O(2) bond lengths are 1.97 Å. Co(1) is bonded to six equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Ir(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. All Co(1)-O(2) bond lengths are 2.09 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ir(1) atoms to form a mixture of distorted corner and face-sharing OBa4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 6-60°. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Ir(1), and one Co(1) atom.