Ba8Ce3(SbO6)4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to one O(2), one O(6), two equivalent O(1), two equivalent O(4), two equivalent O(5), and four equivalent O(3) atoms to form distorted BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ce(2)O6 octahedra, faces with two equivalent Ce(1)O6 octahedra, faces with two equivalent Sb(1)O6 octahedra, and faces with two equivalent Sb(2)O6 octahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form CeO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Ce site, Ce(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CeO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(2), one O(6), and four equivalent O(3) atoms to form SbO6 octahedra that share  a cornercorner with one Ce(2)O6 octahedra, corners with four equivalent Ce(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Ce(1)O6 octahedra, corners with two equivalent Ce(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ce(1), and one Sb(1) atom. In the second O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ce(1), and one Sb(2) atom. In the third O site, O(5) is bonded to four equivalent Ba(1) and one Sb(2) atom to form a mixture of distorted corner and edge-sharing OBa4Sb square pyramids. In the fourth O site, O(6) is bonded to four equivalent Ba(1) and one Sb(1) atom to form distorted edge-sharing OBa4Sb square pyramids. In the fifth O site, O(1) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ce(2), and one Sb(2) atom. In the sixth O site, O(2) is bonded in a linear geometry to four equivalent Ba(1), one Ce(2), and one Sb(1) atom.
Ba8Ce3(SbO6)4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to one O(2), one O(6), two equivalent O(1), two equivalent O(4), two equivalent O(5), and four equivalent O(3) atoms to form distorted BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ce(2)O6 octahedra, faces with two equivalent Ce(1)O6 octahedra, faces with two equivalent Sb(1)O6 octahedra, and faces with two equivalent Sb(2)O6 octahedra. The Ba(1)-O(2) bond length is 3.29 Å. The Ba(1)-O(6) bond length is 2.82 Å. Both Ba(1)-O(1) bond lengths are 3.06 Å. Both Ba(1)-O(4) bond lengths are 3.04 Å. Both Ba(1)-O(5) bond lengths are 2.83 Å. There are two shorter (3.08 Å) and two longer (3.24 Å) Ba(1)-O(3) bond lengths. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form CeO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Ce(1)-O(4) bond lengths are 2.24 Å. All Ce(1)-O(3) bond lengths are 2.24 Å. In the second Ce site, Ce(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CeO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Ce(2)-O(2) bond lengths are 2.22 Å. All Ce(2)-O(1) bond lengths are 2.23 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(2), one O(6), and four equivalent O(3) atoms to form SbO6 octahedra that share  a cornercorner with one Ce(2)O6 octahedra, corners with four equivalent Ce(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. The Sb(1)-O(2) bond length is 1.99 Å. The Sb(1)-O(6) bond length is 1.97 Å. All Sb(1)-O(3) bond lengths are 2.05 Å. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Ce(1)O6 octahedra, corners with two equivalent Ce(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Sb(2)-O(1) bond lengths are 2.05 Å. Both Sb(2)-O(4) bond lengths are 2.06 Å. Both Sb(2)-O(5) bond lengths are 1.95 Å. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ce(1), and one Sb(1) atom. In the second O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ce(1), and one Sb(2) atom. In the third O site, O(5) is bonded to four equivalent Ba(1) and one Sb(2) atom to form a mixture of distorted corner and edge-sharing OBa4Sb square pyramids. In the fourth O site, O(6) is bonded to four equivalent Ba(1) and one Sb(1) atom to form distorted edge-sharing OBa4Sb square pyramids. In the fifth O site, O(1) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ce(2), and one Sb(2) atom. In the sixth O site, O(2) is bonded in a linear geometry to four equivalent Ba(1), one Ce(2), and one Sb(1) atom.