Ca(Cu2O3)2 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second Cu site, Cu(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-50°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Cu(2) and four equivalent Cu(1) atoms to form OCu6 octahedra that share corners with four equivalent O(3)CaCu5 octahedra, corners with two equivalent O(4)Ca2Cu2 tetrahedra, edges with two equivalent O(1)Cu6 octahedra, and edges with six equivalent O(3)CaCu5 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Cu(1), and two equivalent Cu(2) atoms. In the third O site, O(3) is bonded to one Ca(1), two equivalent Cu(2), and three equivalent Cu(1) atoms to form distorted OCaCu5 octahedra that share  a cornercorner with one O(3)CaCu5 octahedra, corners with two equivalent O(1)Cu6 octahedra, edges with three equivalent O(1)Cu6 octahedra, edges with four equivalent O(3)CaCu5 octahedra, and edges with two equivalent O(4)Ca2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 2-51°. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Cu(2) atoms to form distorted OCa2Cu2 tetrahedra that share corners with two equivalent O(1)Cu6 octahedra, corners with two equivalent O(4)Ca2Cu2 tetrahedra, and edges with four equivalent O(3)CaCu5 octahedra. The corner-sharing octahedra are not tilted.
Ca(Cu2O3)2 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Both Ca(1)-O(3) bond lengths are 2.80 Å. Both Ca(1)-O(4) bond lengths are 2.26 Å. All Ca(1)-O(2) bond lengths are 2.42 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. The Cu(1)-O(2) bond length is 1.87 Å. Both Cu(1)-O(1) bond lengths are 2.15 Å. There is one shorter (1.93 Å) and two longer (2.18 Å) Cu(1)-O(3) bond lengths. In the second Cu site, Cu(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-50°. The Cu(2)-O(1) bond length is 2.14 Å. The Cu(2)-O(4) bond length is 1.93 Å. Both Cu(2)-O(2) bond lengths are 2.06 Å. Both Cu(2)-O(3) bond lengths are 2.15 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Cu(2) and four equivalent Cu(1) atoms to form OCu6 octahedra that share corners with four equivalent O(3)CaCu5 octahedra, corners with two equivalent O(4)Ca2Cu2 tetrahedra, edges with two equivalent O(1)Cu6 octahedra, and edges with six equivalent O(3)CaCu5 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Cu(1), and two equivalent Cu(2) atoms. In the third O site, O(3) is bonded to one Ca(1), two equivalent Cu(2), and three equivalent Cu(1) atoms to form distorted OCaCu5 octahedra that share  a cornercorner with one O(3)CaCu5 octahedra, corners with two equivalent O(1)Cu6 octahedra, edges with three equivalent O(1)Cu6 octahedra, edges with four equivalent O(3)CaCu5 octahedra, and edges with two equivalent O(4)Ca2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 2-51°. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Cu(2) atoms to form distorted OCa2Cu2 tetrahedra that share corners with two equivalent O(1)Cu6 octahedra, corners with two equivalent O(4)Ca2Cu2 tetrahedra, and edges with four equivalent O(3)CaCu5 octahedra. The corner-sharing octahedra are not tilted.