CoSbSe crystallizes in the monoclinic P2/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Sb(1) and four equivalent Se(1) atoms to form CoSb2Se4 octahedra that share corners with eight equivalent Co(2)Sb4Se2 octahedra and edges with two equivalent Co(1)Sb2Se4 octahedra. The corner-sharing octahedral tilt angles range from 51-56°. In the second Co site, Co(2) is bonded to four equivalent Sb(1) and two equivalent Se(1) atoms to form CoSb4Se2 octahedra that share corners with eight equivalent Co(1)Sb2Se4 octahedra and edges with two equivalent Co(2)Sb4Se2 octahedra. The corner-sharing octahedral tilt angles range from 51-56°. Sb(1) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Co(2), and one Sb(1) atom. Se(1) is bonded in a distorted trigonal planar geometry to one Co(2) and two equivalent Co(1) atoms.
CoSbSe crystallizes in the monoclinic P2/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Sb(1) and four equivalent Se(1) atoms to form CoSb2Se4 octahedra that share corners with eight equivalent Co(2)Sb4Se2 octahedra and edges with two equivalent Co(1)Sb2Se4 octahedra. The corner-sharing octahedral tilt angles range from 51-56°. Both Co(1)-Sb(1) bond lengths are 2.52 Å. All Co(1)-Se(1) bond lengths are 2.39 Å. In the second Co site, Co(2) is bonded to four equivalent Sb(1) and two equivalent Se(1) atoms to form CoSb4Se2 octahedra that share corners with eight equivalent Co(1)Sb2Se4 octahedra and edges with two equivalent Co(2)Sb4Se2 octahedra. The corner-sharing octahedral tilt angles range from 51-56°. All Co(2)-Sb(1) bond lengths are 2.53 Å. Both Co(2)-Se(1) bond lengths are 2.40 Å. Sb(1) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Co(2), and one Sb(1) atom. The Sb(1)-Sb(1) bond length is 2.80 Å. Se(1) is bonded in a distorted trigonal planar geometry to one Co(2) and two equivalent Co(1) atoms.