Cu2Cd(SO4)2 crystallizes in the monoclinic P2_1/c space group. Cu(1) is bonded to one S(1), one O(2), one O(3), and one O(4) atom to form distorted CuSO3 trigonal pyramids that share corners with three equivalent S(1)CuO3 tetrahedra and  an edgeedge with one Cd(1)O6 octahedra. Cd(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted CdO6 octahedra that share corners with four equivalent S(1)CuO3 tetrahedra and edges with two equivalent Cu(1)SO3 trigonal pyramids. S(1) is bonded to one Cu(1), one O(2), one O(3), and one O(4) atom to form distorted SCuO3 tetrahedra that share corners with two equivalent Cd(1)O6 octahedra and corners with three equivalent Cu(1)SO3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 53-58°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Cd(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cu(1) and one S(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Cu(1), one Cd(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Cu(1), one Cd(1), and one S(1) atom.
Cu2Cd(SO4)2 crystallizes in the monoclinic P2_1/c space group. Cu(1) is bonded to one S(1), one O(2), one O(3), and one O(4) atom to form distorted CuSO3 trigonal pyramids that share corners with three equivalent S(1)CuO3 tetrahedra and  an edgeedge with one Cd(1)O6 octahedra. The Cu(1)-S(1) bond length is 2.22 Å. The Cu(1)-O(2) bond length is 1.93 Å. The Cu(1)-O(3) bond length is 2.18 Å. The Cu(1)-O(4) bond length is 1.97 Å. Cd(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted CdO6 octahedra that share corners with four equivalent S(1)CuO3 tetrahedra and edges with two equivalent Cu(1)SO3 trigonal pyramids. Both Cd(1)-O(1) bond lengths are 2.11 Å. Both Cd(1)-O(3) bond lengths are 2.50 Å. Both Cd(1)-O(4) bond lengths are 2.52 Å. S(1) is bonded to one Cu(1), one O(2), one O(3), and one O(4) atom to form distorted SCuO3 tetrahedra that share corners with two equivalent Cd(1)O6 octahedra and corners with three equivalent Cu(1)SO3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 53-58°. The S(1)-O(2) bond length is 1.51 Å. The S(1)-O(3) bond length is 1.51 Å. The S(1)-O(4) bond length is 1.52 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Cd(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cu(1) and one S(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Cu(1), one Cd(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Cu(1), one Cd(1), and one S(1) atom.