Co3C2(SeO5)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form corner-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 52-66°. In the second Co site, Co(2) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 52-66°. C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. Se(1) is bonded in a trigonal non-coplanar geometry to one O(2) and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Co(2) and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Co(2) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one Se(1) atom.
Co3C2(SeO5)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form corner-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 52-66°. Both Co(1)-O(3) bond lengths are 2.30 Å. All Co(1)-O(4) bond lengths are 2.07 Å. In the second Co site, Co(2) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 52-66°. The Co(2)-O(1) bond length is 2.12 Å. The Co(2)-O(3) bond length is 2.18 Å. There is one shorter (2.13 Å) and one longer (2.15 Å) Co(2)-O(2) bond length. Both Co(2)-O(4) bond lengths are 2.08 Å. C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(3) bond length is 1.28 Å. Se(1) is bonded in a trigonal non-coplanar geometry to one O(2) and two equivalent O(4) atoms. The Se(1)-O(2) bond length is 1.72 Å. Both Se(1)-O(4) bond lengths are 1.75 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Co(2) and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Co(2) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one Se(1) atom.