Mg2MnCo3S8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(2) and three equivalent S(1) atoms to form MgS4 tetrahedra that share corners with three equivalent Mn(1)S6 octahedra and corners with nine equivalent Co(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-62°. Mn(1) is bonded to six equivalent S(1) atoms to form MnS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Co(1)S6 octahedra. Co(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form CoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Mn(1)S6 octahedra, and edges with four equivalent Co(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one Mn(1), and two equivalent Co(1) atoms to form distorted SMgMnCo2 tetrahedra that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgMnCo2 tetrahedra,  an edgeedge with one S(2)MgCo3 tetrahedra, and edges with two equivalent S(1)MgMnCo2 tetrahedra. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Co(1) atoms to form distorted SMgCo3 tetrahedra that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgMnCo2 tetrahedra, and edges with three equivalent S(1)MgMnCo2 tetrahedra.
Mg2MnCo3S8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(2) and three equivalent S(1) atoms to form MgS4 tetrahedra that share corners with three equivalent Mn(1)S6 octahedra and corners with nine equivalent Co(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-62°. The Mg(1)-S(2) bond length is 2.45 Å. All Mg(1)-S(1) bond lengths are 2.44 Å. Mn(1) is bonded to six equivalent S(1) atoms to form MnS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Co(1)S6 octahedra. All Mn(1)-S(1) bond lengths are 2.34 Å. Co(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form CoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Mn(1)S6 octahedra, and edges with four equivalent Co(1)S6 octahedra. Both Co(1)-S(2) bond lengths are 2.30 Å. All Co(1)-S(1) bond lengths are 2.29 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one Mn(1), and two equivalent Co(1) atoms to form distorted SMgMnCo2 tetrahedra that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgMnCo2 tetrahedra,  an edgeedge with one S(2)MgCo3 tetrahedra, and edges with two equivalent S(1)MgMnCo2 tetrahedra. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Co(1) atoms to form distorted SMgCo3 tetrahedra that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgMnCo2 tetrahedra, and edges with three equivalent S(1)MgMnCo2 tetrahedra.