CaCu2(As2O7)2 crystallizes in the monoclinic P2_1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(3), one O(5), one O(6), and one O(9) atom. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(12), one O(14), one O(2), and one O(3) atom to form distorted CuO5 trigonal bipyramids that share  a cornercorner with one As(4)O4 tetrahedra, corners with two equivalent As(1)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. In the second Cu site, Cu(2) is bonded to one O(1), one O(11), one O(13), one O(4), and one O(9) atom to form distorted CuO5 square pyramids that share  a cornercorner with one As(3)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and corners with two equivalent As(4)O4 tetrahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded to one O(12), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one As(4)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. In the second As site, As(2) is bonded to one O(11), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(2)O5 square pyramids and  a cornercorner with one As(3)O4 tetrahedra. In the third As site, As(3) is bonded to one O(1), one O(10), one O(14), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Cu(2)O5 square pyramid,  a cornercorner with one As(2)O4 tetrahedra, and corners with two equivalent Cu(1)O5 trigonal bipyramids. In the fourth As site, As(4) is bonded to one O(13), one O(2), one O(7), and one O(9) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(2)O5 square pyramids,  a cornercorner with one As(1)O4 tetrahedra, and  a cornercorner with one Cu(1)O5 trigonal bipyramid. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(2), and one As(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Cu(1) and one As(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(2) and one As(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ca(1) and one As(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(1) and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one As(1) and one As(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one As(2) and one As(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Ca(1), one Cu(2), and one As(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one As(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(1) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one As(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one As(3) atom.
CaCu2(As2O7)2 crystallizes in the monoclinic P2_1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(3), one O(5), one O(6), and one O(9) atom. The Ca(1)-O(1) bond length is 2.49 Å. The Ca(1)-O(11) bond length is 2.59 Å. The Ca(1)-O(13) bond length is 2.40 Å. The Ca(1)-O(14) bond length is 2.51 Å. The Ca(1)-O(3) bond length is 2.61 Å. The Ca(1)-O(5) bond length is 2.42 Å. The Ca(1)-O(6) bond length is 2.27 Å. The Ca(1)-O(9) bond length is 2.97 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(12), one O(14), one O(2), and one O(3) atom to form distorted CuO5 trigonal bipyramids that share  a cornercorner with one As(4)O4 tetrahedra, corners with two equivalent As(1)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. The Cu(1)-O(10) bond length is 1.83 Å. The Cu(1)-O(12) bond length is 1.88 Å. The Cu(1)-O(14) bond length is 2.44 Å. The Cu(1)-O(2) bond length is 1.87 Å. The Cu(1)-O(3) bond length is 1.93 Å. In the second Cu site, Cu(2) is bonded to one O(1), one O(11), one O(13), one O(4), and one O(9) atom to form distorted CuO5 square pyramids that share  a cornercorner with one As(3)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and corners with two equivalent As(4)O4 tetrahedra. The Cu(2)-O(1) bond length is 1.85 Å. The Cu(2)-O(11) bond length is 1.92 Å. The Cu(2)-O(13) bond length is 2.43 Å. The Cu(2)-O(4) bond length is 1.89 Å. The Cu(2)-O(9) bond length is 1.84 Å. There are four inequivalent As sites. In the first As site, As(1) is bonded to one O(12), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one As(4)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The As(1)-O(12) bond length is 1.72 Å. The As(1)-O(3) bond length is 1.75 Å. The As(1)-O(5) bond length is 1.66 Å. The As(1)-O(7) bond length is 1.80 Å. In the second As site, As(2) is bonded to one O(11), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(2)O5 square pyramids and  a cornercorner with one As(3)O4 tetrahedra. The As(2)-O(11) bond length is 1.73 Å. The As(2)-O(4) bond length is 1.72 Å. The As(2)-O(6) bond length is 1.65 Å. The As(2)-O(8) bond length is 1.81 Å. In the third As site, As(3) is bonded to one O(1), one O(10), one O(14), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Cu(2)O5 square pyramid,  a cornercorner with one As(2)O4 tetrahedra, and corners with two equivalent Cu(1)O5 trigonal bipyramids. The As(3)-O(1) bond length is 1.75 Å. The As(3)-O(10) bond length is 1.72 Å. The As(3)-O(14) bond length is 1.67 Å. The As(3)-O(8) bond length is 1.77 Å. In the fourth As site, As(4) is bonded to one O(13), one O(2), one O(7), and one O(9) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(2)O5 square pyramids,  a cornercorner with one As(1)O4 tetrahedra, and  a cornercorner with one Cu(1)O5 trigonal bipyramid. The As(4)-O(13) bond length is 1.67 Å. The As(4)-O(2) bond length is 1.72 Å. The As(4)-O(7) bond length is 1.79 Å. The As(4)-O(9) bond length is 1.75 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(2), and one As(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Cu(1) and one As(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(2) and one As(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ca(1) and one As(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(1) and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one As(1) and one As(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one As(2) and one As(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Ca(1), one Cu(2), and one As(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one As(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(1) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one As(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one As(3) atom.