Mg2MoCo3S8 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 Mo(1)S6 octahedra and corners with nine equivalent Co(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-65°. Mo(1) is bonded to six equivalent S(1) atoms to form MoS6 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 Mo(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 Mo(1), and two equivalent Co(1) atoms to form distorted SMgCo2Mo trigonal pyramids that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgCo2Mo trigonal pyramids,  an edgeedge with one S(2)MgCo3 tetrahedra, and edges with two equivalent S(1)MgCo2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Co(1) atoms to form SMgCo3 tetrahedra that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgCo2Mo trigonal pyramids, and edges with three equivalent S(1)MgCo2Mo trigonal pyramids.
Mg2MoCo3S8 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 Mo(1)S6 octahedra and corners with nine equivalent Co(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-65°. The Mg(1)-S(2) bond length is 2.51 Å. All Mg(1)-S(1) bond lengths are 2.44 Å. Mo(1) is bonded to six equivalent S(1) atoms to form MoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Co(1)S6 octahedra. All Mo(1)-S(1) bond lengths are 2.47 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 Mo(1)S6 octahedra, and edges with four equivalent Co(1)S6 octahedra. Both Co(1)-S(2) bond lengths are 2.32 Å. All Co(1)-S(1) bond lengths are 2.31 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one Mo(1), and two equivalent Co(1) atoms to form distorted SMgCo2Mo trigonal pyramids that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgCo2Mo trigonal pyramids,  an edgeedge with one S(2)MgCo3 tetrahedra, and edges with two equivalent S(1)MgCo2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Co(1) atoms to form SMgCo3 tetrahedra that share corners with three equivalent S(2)MgCo3 tetrahedra, corners with nine equivalent S(1)MgCo2Mo trigonal pyramids, and edges with three equivalent S(1)MgCo2Mo trigonal pyramids.