Mg2MoCr3S8 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 Mo(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-61°. Mo(1) is bonded to six equivalent S(2) atoms to form MoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. 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 Mo(1)S6 octahedra, and edges with four 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 three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgCr2Mo trigonal pyramids, and edges with three equivalent S(2)MgCr2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1), one Mo(1), and two equivalent Cr(1) atoms to form distorted SMgCr2Mo trigonal pyramids that share corners with three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgCr2Mo trigonal pyramids,  an edgeedge with one S(1)MgCr3 trigonal pyramid, and edges with two equivalent S(2)MgCr2Mo trigonal pyramids.
Mg2MoCr3S8 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 Mo(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-61°. The Mg(1)-S(1) bond length is 2.48 Å. All Mg(1)-S(2) bond lengths are 2.45 Å. Mo(1) is bonded to six equivalent S(2) atoms to form MoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. All Mo(1)-S(2) bond lengths are 2.50 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 Mo(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Both Cr(1)-S(1) bond lengths are 2.44 Å. All Cr(1)-S(2) bond lengths are 2.43 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 three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgCr2Mo trigonal pyramids, and edges with three equivalent S(2)MgCr2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1), one Mo(1), and two equivalent Cr(1) atoms to form distorted SMgCr2Mo trigonal pyramids that share corners with three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgCr2Mo trigonal pyramids,  an edgeedge with one S(1)MgCr3 trigonal pyramid, and edges with two equivalent S(2)MgCr2Mo trigonal pyramids.