CdSeO4 crystallizes in the orthorhombic Pnma space group. Cd(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CdO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Cd(1)O6 octahedra. Se(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SeO4 tetrahedra that share corners with six equivalent Cd(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-57°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Cd(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cd(1) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cd(1) and one Se(1) atom.
CdSeO4 crystallizes in the orthorhombic Pnma space group. Cd(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CdO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Cd(1)O6 octahedra. Both Cd(1)-O(1) bond lengths are 2.29 Å. Both Cd(1)-O(2) bond lengths are 2.23 Å. Both Cd(1)-O(3) bond lengths are 2.41 Å. Se(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SeO4 tetrahedra that share corners with six equivalent Cd(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-57°. The Se(1)-O(1) bond length is 1.67 Å. The Se(1)-O(3) bond length is 1.67 Å. Both Se(1)-O(2) bond lengths are 1.64 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Cd(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cd(1) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cd(1) and one Se(1) atom.