CoSeO5 crystallizes in the monoclinic P2_1/c space group. Co(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form distorted edge-sharing CoO6 octahedra. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Co(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Co(1) and one Se(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Co(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Co(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Co(1) atom.
CoSeO5 crystallizes in the monoclinic P2_1/c space group. Co(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form distorted edge-sharing CoO6 octahedra. The Co(1)-O(1) bond length is 2.05 Å. The Co(1)-O(3) bond length is 1.90 Å. The Co(1)-O(4) bond length is 1.70 Å. The Co(1)-O(5) bond length is 1.67 Å. There is one shorter (1.98 Å) and one longer (2.40 Å) Co(1)-O(2) bond length. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. The Se(1)-O(1) bond length is 1.72 Å. The Se(1)-O(2) bond length is 1.77 Å. The Se(1)-O(3) bond length is 1.75 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Co(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Co(1) and one Se(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Co(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Co(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Co(1) atom.