MgCo2(SbS)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to two equivalent Co(1), four equivalent Sb(2), one S(2), and two equivalent S(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 7-coordinate geometry to two equivalent Mg(1), one Sb(1), two equivalent Sb(2), and two equivalent S(1) atoms. In the second Co site, Co(2) is bonded to one Sb(2), two equivalent Sb(1), one S(1), and two equivalent S(2) atoms to form CoSb3S3 octahedra that share corners with two equivalent S(2)MgCo2Sb tetrahedra and edges with two equivalent Co(2)Sb3S3 octahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Co(2), and one S(2) atom. In the second Sb site, Sb(2) is bonded in a 8-coordinate geometry to four equivalent Mg(1), one Co(2), two equivalent Co(1), and one S(1) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Co(2), two equivalent Co(1), and one Sb(2) atom. In the second S site, S(2) is bonded to one Mg(1), two equivalent Co(2), and one Sb(1) atom to form SMgCo2Sb tetrahedra that share corners with two equivalent Co(2)Sb3S3 octahedra and corners with two equivalent S(2)MgCo2Sb tetrahedra. The corner-sharing octahedral tilt angles are 68°.
MgCo2(SbS)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to two equivalent Co(1), four equivalent Sb(2), one S(2), and two equivalent S(1) atoms. There is one shorter (2.65 Å) and one longer (2.75 Å) Mg(1)-Co(1) bond length. There are two shorter (3.14 Å) and two longer (3.38 Å) Mg(1)-Sb(2) bond lengths. The Mg(1)-S(2) bond length is 2.55 Å. Both Mg(1)-S(1) bond lengths are 2.66 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 7-coordinate geometry to two equivalent Mg(1), one Sb(1), two equivalent Sb(2), and two equivalent S(1) atoms. The Co(1)-Sb(1) bond length is 2.51 Å. Both Co(1)-Sb(2) bond lengths are 2.50 Å. Both Co(1)-S(1) bond lengths are 2.34 Å. In the second Co site, Co(2) is bonded to one Sb(2), two equivalent Sb(1), one S(1), and two equivalent S(2) atoms to form CoSb3S3 octahedra that share corners with two equivalent S(2)MgCo2Sb tetrahedra and edges with two equivalent Co(2)Sb3S3 octahedra. The Co(2)-Sb(2) bond length is 2.53 Å. Both Co(2)-Sb(1) bond lengths are 2.55 Å. The Co(2)-S(1) bond length is 2.26 Å. Both Co(2)-S(2) bond lengths are 2.29 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Co(2), and one S(2) atom. The Sb(1)-S(2) bond length is 2.63 Å. In the second Sb site, Sb(2) is bonded in a 8-coordinate geometry to four equivalent Mg(1), one Co(2), two equivalent Co(1), and one S(1) atom. The Sb(2)-S(1) bond length is 2.98 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Co(2), two equivalent Co(1), and one Sb(2) atom. In the second S site, S(2) is bonded to one Mg(1), two equivalent Co(2), and one Sb(1) atom to form SMgCo2Sb tetrahedra that share corners with two equivalent Co(2)Sb3S3 octahedra and corners with two equivalent S(2)MgCo2Sb tetrahedra. The corner-sharing octahedral tilt angles are 68°.