CuAl2O4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra, edges with two equivalent Cu(1)O6 octahedra, and edges with four equivalent Al(2)O6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form AlO4 tetrahedra that share corners with six equivalent Cu(1)O6 octahedra and corners with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. In the second Al site, Al(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra, edges with two equivalent Al(2)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Cu(1), one Al(1), and one Al(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Cu(1), one Al(1), and two equivalent Al(2) atoms.
CuAl2O4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra, edges with two equivalent Cu(1)O6 octahedra, and edges with four equivalent Al(2)O6 octahedra. Both Cu(1)-O(2) bond lengths are 2.27 Å. All Cu(1)-O(1) bond lengths are 1.98 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form AlO4 tetrahedra that share corners with six equivalent Cu(1)O6 octahedra and corners with six equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. Both Al(1)-O(1) bond lengths are 1.82 Å. Both Al(1)-O(2) bond lengths are 1.81 Å. In the second Al site, Al(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra, edges with two equivalent Al(2)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. Both Al(2)-O(1) bond lengths are 1.96 Å. All Al(2)-O(2) bond lengths are 1.94 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Cu(1), one Al(1), and one Al(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Cu(1), one Al(1), and two equivalent Al(2) atoms.