Ca(CuO2)2 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Cu(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of corner and edge-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-47°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and three equivalent Cu(1) atoms to form distorted OCa2Cu3 trigonal bipyramids that share corners with four equivalent O(3)Ca2Cu4 octahedra, corners with five equivalent O(2)Ca2Cu2 tetrahedra, corners with two equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with three equivalent O(3)Ca2Cu4 octahedra,  an edgeedge with one O(2)Ca2Cu2 tetrahedra, and edges with five equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-44°. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Cu(1) atoms to form distorted OCa2Cu2 tetrahedra that share corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with ten equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with four equivalent O(3)Ca2Cu4 octahedra, and edges with two equivalent O(1)Ca2Cu3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Ca(1) and four equivalent Cu(1) atoms to form OCa2Cu4 octahedra that share corners with two equivalent O(3)Ca2Cu4 octahedra, corners with eight equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with two equivalent O(3)Ca2Cu4 octahedra, edges with four equivalent O(2)Ca2Cu2 tetrahedra, and edges with six equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 47°.
Ca(CuO2)2 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Both Ca(1)-O(2) bond lengths are 2.27 Å. Both Ca(1)-O(3) bond lengths are 2.60 Å. All Ca(1)-O(1) bond lengths are 2.41 Å. Cu(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of corner and edge-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-47°. The Cu(1)-O(2) bond length is 1.87 Å. Both Cu(1)-O(3) bond lengths are 2.17 Å. There is one shorter (1.89 Å) and two longer (2.09 Å) Cu(1)-O(1) bond lengths. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and three equivalent Cu(1) atoms to form distorted OCa2Cu3 trigonal bipyramids that share corners with four equivalent O(3)Ca2Cu4 octahedra, corners with five equivalent O(2)Ca2Cu2 tetrahedra, corners with two equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with three equivalent O(3)Ca2Cu4 octahedra,  an edgeedge with one O(2)Ca2Cu2 tetrahedra, and edges with five equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-44°. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Cu(1) atoms to form distorted OCa2Cu2 tetrahedra that share corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with ten equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with four equivalent O(3)Ca2Cu4 octahedra, and edges with two equivalent O(1)Ca2Cu3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Ca(1) and four equivalent Cu(1) atoms to form OCa2Cu4 octahedra that share corners with two equivalent O(3)Ca2Cu4 octahedra, corners with eight equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with two equivalent O(3)Ca2Cu4 octahedra, edges with four equivalent O(2)Ca2Cu2 tetrahedra, and edges with six equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 47°.