MgVCr3S8 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one S(4) and three equivalent S(2) atoms to form MgS4 tetrahedra that share corners with three equivalent V(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 61-63°. V(1) is bonded to three equivalent S(2) and three equivalent S(3) atoms to form distorted VS6 octahedra that share corners with three equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. Cr(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with three equivalent Mg(1)S4 tetrahedra, edges with two equivalent V(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to three equivalent Cr(1) atoms. In the second S site, S(2) is bonded to one Mg(1), one V(1), and two equivalent Cr(1) atoms to form SMgVCr2 tetrahedra that share  a cornercorner with one S(4)MgCr3 tetrahedra, corners with two equivalent S(2)MgVCr2 tetrahedra,  an edgeedge with one S(4)MgCr3 tetrahedra, and edges with two equivalent S(2)MgVCr2 tetrahedra. In the third S site, S(3) is bonded in a distorted T-shaped geometry to one V(1) and two equivalent Cr(1) atoms. In the fourth S site, S(4) is bonded to one Mg(1) and three equivalent Cr(1) atoms to form a mixture of distorted edge and corner-sharing SMgCr3 tetrahedra.
MgVCr3S8 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one S(4) and three equivalent S(2) atoms to form MgS4 tetrahedra that share corners with three equivalent V(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 61-63°. The Mg(1)-S(4) bond length is 2.37 Å. All Mg(1)-S(2) bond lengths are 2.41 Å. V(1) is bonded to three equivalent S(2) and three equivalent S(3) atoms to form distorted VS6 octahedra that share corners with three equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. All V(1)-S(2) bond lengths are 2.57 Å. All V(1)-S(3) bond lengths are 2.25 Å. Cr(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with three equivalent Mg(1)S4 tetrahedra, edges with two equivalent V(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. The Cr(1)-S(1) bond length is 2.37 Å. The Cr(1)-S(4) bond length is 2.43 Å. Both Cr(1)-S(2) bond lengths are 2.41 Å. Both Cr(1)-S(3) bond lengths are 2.40 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to three equivalent Cr(1) atoms. In the second S site, S(2) is bonded to one Mg(1), one V(1), and two equivalent Cr(1) atoms to form SMgVCr2 tetrahedra that share  a cornercorner with one S(4)MgCr3 tetrahedra, corners with two equivalent S(2)MgVCr2 tetrahedra,  an edgeedge with one S(4)MgCr3 tetrahedra, and edges with two equivalent S(2)MgVCr2 tetrahedra. In the third S site, S(3) is bonded in a distorted T-shaped geometry to one V(1) and two equivalent Cr(1) atoms. In the fourth S site, S(4) is bonded to one Mg(1) and three equivalent Cr(1) atoms to form a mixture of distorted edge and corner-sharing SMgCr3 tetrahedra.