Cr4Al(CuO4)3 crystallizes in the cubic Im-3 space group. Cr(1) is bonded to six equivalent O(1) atoms to form CrO6 octahedra that share corners with six equivalent Cr(1)O6 octahedra and faces with two equivalent Al(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. Cu(1) 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 Cr(1)O6 octahedra. O(1) is bonded in a 3-coordinate geometry to two equivalent Cr(1), one Cu(1), and one Al(1) atom.
Cr4Al(CuO4)3 crystallizes in the cubic Im-3 space group. Cr(1) is bonded to six equivalent O(1) atoms to form CrO6 octahedra that share corners with six equivalent Cr(1)O6 octahedra and faces with two equivalent Al(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. All Cr(1)-O(1) bond lengths are 1.98 Å. Cu(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. All Cu(1)-O(1) bond lengths are 1.88 Å. Al(1) is bonded to twelve equivalent O(1) atoms to form AlO12 cuboctahedra that share faces with eight equivalent Cr(1)O6 octahedra. All Al(1)-O(1) bond lengths are 2.53 Å. O(1) is bonded in a 3-coordinate geometry to two equivalent Cr(1), one Cu(1), and one Al(1) atom.