Ca2Cu9O13 crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(6) and four equivalent O(7) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles are 9°. In the second Cu site, Cu(2) is bonded to one O(4), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the third Cu site, Cu(3) is bonded to one O(5), two equivalent O(6), and three equivalent O(7) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 2-11°. In the fourth Cu site, Cu(4) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-50°. In the fifth Cu site, Cu(5) is bonded to one O(2), one O(7), two equivalent O(5), and two equivalent O(6) atoms to form a mixture of distorted edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 2-50°. There are seven inequivalent O sites. In the first O site, O(7) is bonded to one Cu(5), two equivalent Cu(1), and three equivalent Cu(3) atoms to form OCu6 octahedra that share corners with two equivalent O(7)Cu6 octahedra, corners with two equivalent O(6)Cu5 square pyramids,  a cornercorner with one O(2)Ca2Cu2 tetrahedra, edges with five equivalent O(7)Cu6 octahedra, and edges with five equivalent O(6)Cu5 square pyramids. The corner-sharing octahedra are not tilted. In the second O site, O(1) is bonded to two equivalent Cu(4) and four equivalent Cu(2) atoms to form OCu6 octahedra that share corners with four equivalent O(3)Cu5 square pyramids, corners with two equivalent O(2)Ca2Cu2 tetrahedra, edges with two equivalent O(1)Cu6 octahedra, edges with six equivalent O(3)Cu5 square pyramids, and edges with four equivalent O(4)Ca2Cu3 trigonal bipyramids. In the third O site, O(2) is bonded to two equivalent Ca(1), one Cu(4), and one Cu(5) atom to form distorted OCa2Cu2 tetrahedra that share  a cornercorner with one O(1)Cu6 octahedra,  a cornercorner with one O(7)Cu6 octahedra, corners with two equivalent O(3)Cu5 square pyramids, corners with two equivalent O(6)Cu5 square pyramids, corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with four equivalent O(4)Ca2Cu3 trigonal bipyramids, and  an edgeedge with one O(4)Ca2Cu3 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(3) is bonded to two equivalent Cu(4) and three equivalent Cu(2) atoms to form distorted OCu5 square pyramids that share corners with two equivalent O(1)Cu6 octahedra, corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with five equivalent O(4)Ca2Cu3 trigonal bipyramids, edges with three equivalent O(1)Cu6 octahedra, edges with four equivalent O(3)Cu5 square pyramids, and  an edgeedge with one O(4)Ca2Cu3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 3°. In the fifth O site, O(4) is bonded to two equivalent Ca(1), one Cu(2), and two equivalent Cu(4) atoms to form distorted OCa2Cu3 trigonal bipyramids that share corners with five equivalent O(3)Cu5 square pyramids, corners with four equivalent O(2)Ca2Cu2 tetrahedra, edges with two equivalent O(1)Cu6 octahedra,  an edgeedge with one O(3)Cu5 square pyramid,  an edgeedge with one O(2)Ca2Cu2 tetrahedra, and edges with two equivalent O(4)Ca2Cu3 trigonal bipyramids. In the sixth O site, O(5) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Cu(3), and two equivalent Cu(5) atoms. In the seventh O site, O(6) is bonded to one Cu(1), two equivalent Cu(3), and two equivalent Cu(5) atoms to form distorted OCu5 square pyramids that share corners with two equivalent O(7)Cu6 octahedra,  a cornercorner with one O(6)Cu5 square pyramid, corners with two equivalent O(2)Ca2Cu2 tetrahedra, edges with five equivalent O(7)Cu6 octahedra, and edges with two equivalent O(6)Cu5 square pyramids. The corner-sharing octahedral tilt angles are 8°.
Ca2Cu9O13 crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. Both Ca(1)-O(2) bond lengths are 2.26 Å. Both Ca(1)-O(4) bond lengths are 2.42 Å. Both Ca(1)-O(5) bond lengths are 2.44 Å. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(6) and four equivalent O(7) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles are 9°. Both Cu(1)-O(6) bond lengths are 1.98 Å. All Cu(1)-O(7) bond lengths are 2.12 Å. In the second Cu site, Cu(2) is bonded to one O(4), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. The Cu(2)-O(4) bond length is 1.88 Å. Both Cu(2)-O(1) bond lengths are 2.14 Å. There is one shorter (1.95 Å) and two longer (2.17 Å) Cu(2)-O(3) bond lengths. In the third Cu site, Cu(3) is bonded to one O(5), two equivalent O(6), and three equivalent O(7) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 2-11°. The Cu(3)-O(5) bond length is 1.89 Å. Both Cu(3)-O(6) bond lengths are 2.19 Å. There is one shorter (1.95 Å) and two longer (2.17 Å) Cu(3)-O(7) bond lengths. In the fourth Cu site, Cu(4) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-50°. The Cu(4)-O(1) bond length is 2.14 Å. The Cu(4)-O(2) bond length is 1.91 Å. Both Cu(4)-O(3) bond lengths are 2.13 Å. Both Cu(4)-O(4) bond lengths are 2.06 Å. In the fifth Cu site, Cu(5) is bonded to one O(2), one O(7), two equivalent O(5), and two equivalent O(6) atoms to form a mixture of distorted edge and corner-sharing CuO6 octahedra. The corner-sharing octahedral tilt angles range from 2-50°. The Cu(5)-O(2) bond length is 1.98 Å. The Cu(5)-O(7) bond length is 2.41 Å. Both Cu(5)-O(5) bond lengths are 2.05 Å. Both Cu(5)-O(6) bond lengths are 2.10 Å. There are seven inequivalent O sites. In the first O site, O(7) is bonded to one Cu(5), two equivalent Cu(1), and three equivalent Cu(3) atoms to form OCu6 octahedra that share corners with two equivalent O(7)Cu6 octahedra, corners with two equivalent O(6)Cu5 square pyramids,  a cornercorner with one O(2)Ca2Cu2 tetrahedra, edges with five equivalent O(7)Cu6 octahedra, and edges with five equivalent O(6)Cu5 square pyramids. The corner-sharing octahedra are not tilted. In the second O site, O(1) is bonded to two equivalent Cu(4) and four equivalent Cu(2) atoms to form OCu6 octahedra that share corners with four equivalent O(3)Cu5 square pyramids, corners with two equivalent O(2)Ca2Cu2 tetrahedra, edges with two equivalent O(1)Cu6 octahedra, edges with six equivalent O(3)Cu5 square pyramids, and edges with four equivalent O(4)Ca2Cu3 trigonal bipyramids. In the third O site, O(2) is bonded to two equivalent Ca(1), one Cu(4), and one Cu(5) atom to form distorted OCa2Cu2 tetrahedra that share  a cornercorner with one O(1)Cu6 octahedra,  a cornercorner with one O(7)Cu6 octahedra, corners with two equivalent O(3)Cu5 square pyramids, corners with two equivalent O(6)Cu5 square pyramids, corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with four equivalent O(4)Ca2Cu3 trigonal bipyramids, and  an edgeedge with one O(4)Ca2Cu3 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(3) is bonded to two equivalent Cu(4) and three equivalent Cu(2) atoms to form distorted OCu5 square pyramids that share corners with two equivalent O(1)Cu6 octahedra, corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with five equivalent O(4)Ca2Cu3 trigonal bipyramids, edges with three equivalent O(1)Cu6 octahedra, edges with four equivalent O(3)Cu5 square pyramids, and  an edgeedge with one O(4)Ca2Cu3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 3°. In the fifth O site, O(4) is bonded to two equivalent Ca(1), one Cu(2), and two equivalent Cu(4) atoms to form distorted OCa2Cu3 trigonal bipyramids that share corners with five equivalent O(3)Cu5 square pyramids, corners with four equivalent O(2)Ca2Cu2 tetrahedra, edges with two equivalent O(1)Cu6 octahedra,  an edgeedge with one O(3)Cu5 square pyramid,  an edgeedge with one O(2)Ca2Cu2 tetrahedra, and edges with two equivalent O(4)Ca2Cu3 trigonal bipyramids. In the sixth O site, O(5) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Cu(3), and two equivalent Cu(5) atoms. In the seventh O site, O(6) is bonded to one Cu(1), two equivalent Cu(3), and two equivalent Cu(5) atoms to form distorted OCu5 square pyramids that share corners with two equivalent O(7)Cu6 octahedra,  a cornercorner with one O(6)Cu5 square pyramid, corners with two equivalent O(2)Ca2Cu2 tetrahedra, edges with five equivalent O(7)Cu6 octahedra, and edges with two equivalent O(6)Cu5 square pyramids. The corner-sharing octahedral tilt angles are 8°.