Cu7AlO12 crystallizes in the cubic Im-3 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to six equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Cu(1)O6 octahedra and faces with two equivalent Al(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 43°. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(1) atoms. Al(1) is bonded to twelve equivalent O(1) atoms to form AlO12 cuboctahedra that share faces with eight equivalent Cu(1)O6 octahedra. O(1) is bonded in a 3-coordinate geometry to one Cu(2), two equivalent Cu(1), and one Al(1) atom.
Cu7AlO12 crystallizes in the cubic Im-3 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to six equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Cu(1)O6 octahedra and faces with two equivalent Al(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 43°. All Cu(1)-O(1) bond lengths are 1.94 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(1) atoms. All Cu(2)-O(1) bond lengths are 1.89 Å. Al(1) is bonded to twelve equivalent O(1) atoms to form AlO12 cuboctahedra that share faces with eight equivalent Cu(1)O6 octahedra. All Al(1)-O(1) bond lengths are 2.48 Å. O(1) is bonded in a 3-coordinate geometry to one Cu(2), two equivalent Cu(1), and one Al(1) atom.