Cd2SO6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(5) atoms to form distorted CdO6 octahedra that share corners with two equivalent Cd(2)O6 pentagonal pyramids, corners with three equivalent S(1)O4 tetrahedra,  an edgeedge with one Cd(1)O6 octahedra, and edges with two equivalent Cd(2)O6 pentagonal pyramids. In the second Cd site, Cd(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(6) atoms to form distorted CdO6 pentagonal pyramids that share corners with two equivalent Cd(1)O6 octahedra, corners with three equivalent S(1)O4 tetrahedra, edges with two equivalent Cd(1)O6 octahedra, and  an edgeedge with one Cd(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 51-54°. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with three equivalent Cd(1)O6 octahedra and corners with three equivalent Cd(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 46-51°. There are six inequivalent O sites. In the first O site, O(6) is bonded in a trigonal non-coplanar geometry to one Cd(1) and two equivalent Cd(2) atoms. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Cd(1), one Cd(2), and one S(1) atom. In the third O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cd(2) and one S(1) atom. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cd(1), one Cd(2), and one S(1) atom. In the fifth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cd(1) and one S(1) atom. In the sixth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Cd(2) and two equivalent Cd(1) atoms.
Cd2SO6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(5) atoms to form distorted CdO6 octahedra that share corners with two equivalent Cd(2)O6 pentagonal pyramids, corners with three equivalent S(1)O4 tetrahedra,  an edgeedge with one Cd(1)O6 octahedra, and edges with two equivalent Cd(2)O6 pentagonal pyramids. The Cd(1)-O(1) bond length is 2.42 Å. The Cd(1)-O(3) bond length is 2.45 Å. The Cd(1)-O(4) bond length is 2.38 Å. The Cd(1)-O(6) bond length is 2.21 Å. There is one shorter (2.23 Å) and one longer (2.28 Å) Cd(1)-O(5) bond length. In the second Cd site, Cd(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(6) atoms to form distorted CdO6 pentagonal pyramids that share corners with two equivalent Cd(1)O6 octahedra, corners with three equivalent S(1)O4 tetrahedra, edges with two equivalent Cd(1)O6 octahedra, and  an edgeedge with one Cd(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 51-54°. The Cd(2)-O(1) bond length is 2.46 Å. The Cd(2)-O(2) bond length is 2.36 Å. The Cd(2)-O(3) bond length is 2.44 Å. The Cd(2)-O(5) bond length is 2.22 Å. There is one shorter (2.25 Å) and one longer (2.27 Å) Cd(2)-O(6) bond length. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with three equivalent Cd(1)O6 octahedra and corners with three equivalent Cd(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 46-51°. The S(1)-O(1) bond length is 1.50 Å. The S(1)-O(2) bond length is 1.48 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.49 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a trigonal non-coplanar geometry to one Cd(1) and two equivalent Cd(2) atoms. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Cd(1), one Cd(2), and one S(1) atom. In the third O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cd(2) and one S(1) atom. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cd(1), one Cd(2), and one S(1) atom. In the fifth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cd(1) and one S(1) atom. In the sixth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Cd(2) and two equivalent Cd(1) atoms.