Mg2MoAl3S8 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 Al(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-62°. 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 Al(1)S6 octahedra. Al(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form AlS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Mo(1)S6 octahedra, and edges with four equivalent Al(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 Al(1) atoms to form distorted SMgAl2Mo trigonal pyramids that share corners with three equivalent S(2)MgAl3 trigonal pyramids, corners with nine equivalent S(1)MgAl2Mo trigonal pyramids,  an edgeedge with one S(2)MgAl3 trigonal pyramid, and edges with two equivalent S(1)MgAl2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Al(1) atoms to form distorted SMgAl3 trigonal pyramids that share corners with three equivalent S(2)MgAl3 trigonal pyramids, corners with nine equivalent S(1)MgAl2Mo trigonal pyramids, and edges with three equivalent S(1)MgAl2Mo trigonal pyramids.
Mg2MoAl3S8 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 Al(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-62°. The Mg(1)-S(2) bond length is 2.46 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 Al(1)S6 octahedra. All Mo(1)-S(1) bond lengths are 2.50 Å. Al(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form AlS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Mo(1)S6 octahedra, and edges with four equivalent Al(1)S6 octahedra. Both Al(1)-S(2) bond lengths are 2.46 Å. All Al(1)-S(1) bond lengths are 2.44 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 Al(1) atoms to form distorted SMgAl2Mo trigonal pyramids that share corners with three equivalent S(2)MgAl3 trigonal pyramids, corners with nine equivalent S(1)MgAl2Mo trigonal pyramids,  an edgeedge with one S(2)MgAl3 trigonal pyramid, and edges with two equivalent S(1)MgAl2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Al(1) atoms to form distorted SMgAl3 trigonal pyramids that share corners with three equivalent S(2)MgAl3 trigonal pyramids, corners with nine equivalent S(1)MgAl2Mo trigonal pyramids, and edges with three equivalent S(1)MgAl2Mo trigonal pyramids.