MgCo2(AsS)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to two equivalent As(2), one S(1), and two equivalent S(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one As(2), two equivalent As(1), one S(1), and two equivalent S(2) atoms to form CoAs3S3 octahedra that share corners with two equivalent As(1)Co3S tetrahedra and edges with two equivalent Co(1)As3S3 octahedra. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one As(1), two equivalent As(2), and two equivalent S(1) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one Co(2), two equivalent Co(1), and one S(2) atom to form AsCo3S tetrahedra that share corners with two equivalent Co(1)As3S3 octahedra and corners with two equivalent As(1)Co3S tetrahedra. The corner-sharing octahedral tilt angles are 70°. In the second As site, As(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Co(1), and two equivalent Co(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), and two equivalent Co(2) atoms. In the second S site, S(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), two equivalent Co(1), and one As(1) atom.
MgCo2(AsS)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to two equivalent As(2), one S(1), and two equivalent S(2) atoms. There is one shorter (2.57 Å) and one longer (2.68 Å) Mg(1)-As(2) bond length. The Mg(1)-S(1) bond length is 2.43 Å. Both Mg(1)-S(2) bond lengths are 2.60 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one As(2), two equivalent As(1), one S(1), and two equivalent S(2) atoms to form CoAs3S3 octahedra that share corners with two equivalent As(1)Co3S tetrahedra and edges with two equivalent Co(1)As3S3 octahedra. The Co(1)-As(2) bond length is 2.37 Å. Both Co(1)-As(1) bond lengths are 2.39 Å. The Co(1)-S(1) bond length is 2.20 Å. Both Co(1)-S(2) bond lengths are 2.30 Å. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one As(1), two equivalent As(2), and two equivalent S(1) atoms. The Co(2)-As(1) bond length is 2.40 Å. Both Co(2)-As(2) bond lengths are 2.44 Å. Both Co(2)-S(1) bond lengths are 2.23 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to one Co(2), two equivalent Co(1), and one S(2) atom to form AsCo3S tetrahedra that share corners with two equivalent Co(1)As3S3 octahedra and corners with two equivalent As(1)Co3S tetrahedra. The corner-sharing octahedral tilt angles are 70°. The As(1)-S(2) bond length is 2.57 Å. In the second As site, As(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Co(1), and two equivalent Co(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), and two equivalent Co(2) atoms. In the second S site, S(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), two equivalent Co(1), and one As(1) atom.