Mg2Cr3CoS8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(1) and three equivalent S(2) atoms to form MgS4 tetrahedra that share corners with three equivalent Co(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 57-61°. Cr(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CrS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Co(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Co(1) is bonded to six equivalent S(2) atoms to form CoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1) and three equivalent Cr(1) atoms to form distorted SMgCr3 trigonal pyramids that share corners with nine equivalent S(2)MgCr2Co tetrahedra, corners with three equivalent S(1)MgCr3 trigonal pyramids, and edges with three equivalent S(2)MgCr2Co tetrahedra. In the second S site, S(2) is bonded to one Mg(1), two equivalent Cr(1), and one Co(1) atom to form distorted SMgCr2Co tetrahedra that share corners with nine equivalent S(2)MgCr2Co tetrahedra, corners with three equivalent S(1)MgCr3 trigonal pyramids, edges with two equivalent S(2)MgCr2Co tetrahedra, and  an edgeedge with one S(1)MgCr3 trigonal pyramid.
Mg2Cr3CoS8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(1) and three equivalent S(2) atoms to form MgS4 tetrahedra that share corners with three equivalent Co(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 57-61°. The Mg(1)-S(1) bond length is 2.42 Å. All Mg(1)-S(2) bond lengths are 2.46 Å. Cr(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CrS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Co(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Both Cr(1)-S(1) bond lengths are 2.41 Å. All Cr(1)-S(2) bond lengths are 2.42 Å. Co(1) is bonded to six equivalent S(2) atoms to form CoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. All Co(1)-S(2) bond lengths are 2.32 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1) and three equivalent Cr(1) atoms to form distorted SMgCr3 trigonal pyramids that share corners with nine equivalent S(2)MgCr2Co tetrahedra, corners with three equivalent S(1)MgCr3 trigonal pyramids, and edges with three equivalent S(2)MgCr2Co tetrahedra. In the second S site, S(2) is bonded to one Mg(1), two equivalent Cr(1), and one Co(1) atom to form distorted SMgCr2Co tetrahedra that share corners with nine equivalent S(2)MgCr2Co tetrahedra, corners with three equivalent S(1)MgCr3 trigonal pyramids, edges with two equivalent S(2)MgCr2Co tetrahedra, and  an edgeedge with one S(1)MgCr3 trigonal pyramid.