Ba3CeRu2O9 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(2) and nine equivalent O(1) 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 Ru(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ce(1)O6 octahedra, and faces with four equivalent Ru(1)O6 octahedra. The corner-sharing octahedral tilt angles are 13°. 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 Ce(1)O6 octahedra, and faces with six equivalent Ru(1)O6 octahedra. Ce(1) is bonded to six equivalent O(1) atoms to form CeO6 octahedra that share corners with six equivalent Ru(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Ru(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form RuO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ce(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Ru(1)O6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Ce(1), and one Ru(1) atom. In the second O site, O(2) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ru(1) atoms to form a mixture of distorted corner and face-sharing OBa4Ru2 octahedra. The corner-sharing octahedral tilt angles range from 4-60°.
Ba3CeRu2O9 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(2) and nine equivalent O(1) 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 Ru(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ce(1)O6 octahedra, and faces with four equivalent Ru(1)O6 octahedra. The corner-sharing octahedral tilt angles are 13°. All Ba(1)-O(2) bond lengths are 2.91 Å. There are six shorter (2.99 Å) and three longer (3.20 Å) Ba(1)-O(1) 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 Ce(1)O6 octahedra, and faces with six equivalent Ru(1)O6 octahedra. All Ba(2)-O(1) bond lengths are 3.01 Å. All Ba(2)-O(2) bond lengths are 2.99 Å. Ce(1) is bonded to six equivalent O(1) atoms to form CeO6 octahedra that share corners with six equivalent Ru(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. All Ce(1)-O(1) bond lengths are 2.23 Å. Ru(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form RuO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ce(1)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Ru(1)O6 octahedra. The corner-sharing octahedra are not tilted. All Ru(1)-O(1) bond lengths are 2.00 Å. All Ru(1)-O(2) bond lengths are 2.04 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Ce(1), and one Ru(1) atom. In the second O site, O(2) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ru(1) atoms to form a mixture of distorted corner and face-sharing OBa4Ru2 octahedra. The corner-sharing octahedral tilt angles range from 4-60°.