Ba2CeHfO6 crystallizes in the cubic Pn-3 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to twelve equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ce(1)O6 octahedra, and faces with four equivalent Hf(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to twelve equivalent O(1) atoms to form distorted BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, corners with eight equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ce(1)O6 octahedra, and faces with four equivalent Hf(1)O6 octahedra. Ce(1) is bonded to six equivalent O(1) atoms to form CeO6 octahedra that share corners with six equivalent Hf(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 13°. Hf(1) is bonded to six equivalent O(1) atoms to form HfO6 octahedra that share corners with six equivalent Ce(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 13°. O(1) is bonded in a 2-coordinate geometry to one Ba(1), three equivalent Ba(2), one Ce(1), and one Hf(1) atom.
Ba2CeHfO6 crystallizes in the cubic Pn-3 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to twelve equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ce(1)O6 octahedra, and faces with four equivalent Hf(1)O6 octahedra. All Ba(1)-O(1) bond lengths are 3.06 Å. In the second Ba site, Ba(2) is bonded to twelve equivalent O(1) atoms to form distorted BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, corners with eight equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ce(1)O6 octahedra, and faces with four equivalent Hf(1)O6 octahedra. There are a spread of Ba(2)-O(1) bond distances ranging from 2.82-3.31 Å. Ce(1) is bonded to six equivalent O(1) atoms to form CeO6 octahedra that share corners with six equivalent Hf(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 13°. All Ce(1)-O(1) bond lengths are 2.26 Å. Hf(1) is bonded to six equivalent O(1) atoms to form HfO6 octahedra that share corners with six equivalent Ce(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 13°. All Hf(1)-O(1) bond lengths are 2.10 Å. O(1) is bonded in a 2-coordinate geometry to one Ba(1), three equivalent Ba(2), one Ce(1), and one Hf(1) atom.