Co5(SeO3)4Cl2 crystallizes in the triclinic P-1 space group. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent Cl(1) atoms to form distorted CoCl2O4 octahedra that share corners with two equivalent Co(2)O5 trigonal bipyramids and edges with two equivalent Co(3)ClO5 octahedra. In the second Co site, Co(2) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form distorted CoO5 trigonal bipyramids that share  a cornercorner with one Co(1)Cl2O4 octahedra,  an edgeedge with one Co(3)ClO5 octahedra, and  an edgeedge with one Co(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. In the third Co site, Co(3) is bonded to one O(1), one O(3), one O(5), two equivalent O(6), and one Cl(1) atom to form distorted CoClO5 octahedra that share  an edgeedge with one Co(1)Cl2O4 octahedra,  an edgeedge with one Co(3)ClO5 octahedra, and  an edgeedge with one Co(2)O5 trigonal bipyramid. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(4), and one O(5) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(2), one O(3), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Co(2), one Co(3), and one Se(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Co(1), one Co(2), and one Se(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(2), one Co(3), and one Se(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Co(2) and one Se(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(1), one Co(3), and one Se(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Co(3) and one Se(2) atom. Cl(1) is bonded in an L-shaped geometry to one Co(1) and one Co(3) atom.
Co5(SeO3)4Cl2 crystallizes in the triclinic P-1 space group. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent Cl(1) atoms to form distorted CoCl2O4 octahedra that share corners with two equivalent Co(2)O5 trigonal bipyramids and edges with two equivalent Co(3)ClO5 octahedra. Both Co(1)-O(2) bond lengths are 2.16 Å. Both Co(1)-O(5) bond lengths are 2.04 Å. Both Co(1)-Cl(1) bond lengths are 2.53 Å. In the second Co site, Co(2) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form distorted CoO5 trigonal bipyramids that share  a cornercorner with one Co(1)Cl2O4 octahedra,  an edgeedge with one Co(3)ClO5 octahedra, and  an edgeedge with one Co(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. The Co(2)-O(1) bond length is 2.19 Å. The Co(2)-O(2) bond length is 2.08 Å. The Co(2)-O(3) bond length is 2.02 Å. There is one shorter (2.05 Å) and one longer (2.07 Å) Co(2)-O(4) bond length. In the third Co site, Co(3) is bonded to one O(1), one O(3), one O(5), two equivalent O(6), and one Cl(1) atom to form distorted CoClO5 octahedra that share  an edgeedge with one Co(1)Cl2O4 octahedra,  an edgeedge with one Co(3)ClO5 octahedra, and  an edgeedge with one Co(2)O5 trigonal bipyramid. The Co(3)-O(1) bond length is 2.17 Å. The Co(3)-O(3) bond length is 2.09 Å. The Co(3)-O(5) bond length is 2.15 Å. There is one shorter (2.06 Å) and one longer (2.14 Å) Co(3)-O(6) bond length. The Co(3)-Cl(1) bond length is 2.51 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(4), and one O(5) atom. The Se(1)-O(1) bond length is 1.73 Å. The Se(1)-O(4) bond length is 1.75 Å. The Se(1)-O(5) bond length is 1.73 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(2), one O(3), and one O(6) atom. The Se(2)-O(2) bond length is 1.75 Å. The Se(2)-O(3) bond length is 1.74 Å. The Se(2)-O(6) bond length is 1.73 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Co(2), one Co(3), and one Se(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Co(1), one Co(2), and one Se(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(2), one Co(3), and one Se(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Co(2) and one Se(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(1), one Co(3), and one Se(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Co(3) and one Se(2) atom. Cl(1) is bonded in an L-shaped geometry to one Co(1) and one Co(3) atom.