MgCrAlS4 is Spinel-derived structured and crystallizes in the orthorhombic Imma space group. Mg(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form MgS4 tetrahedra that share corners with six equivalent Cr(1)S6 octahedra and corners with six equivalent Al(1)S6 octahedra. The corner-sharing octahedral tilt angles are 59°. Cr(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form CrS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Cr(1)S6 octahedra, and edges with four equivalent Al(1)S6 octahedra. Al(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form AlS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Al(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), two equivalent Cr(1), and one Al(1) atom to form distorted SMgAlCr2 trigonal pyramids that share corners with six equivalent S(2)MgAl2Cr trigonal pyramids, corners with six equivalent S(1)MgAlCr2 trigonal pyramids,  an edgeedge with one S(1)MgAlCr2 trigonal pyramid, and edges with two equivalent S(2)MgAl2Cr trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1), one Cr(1), and two equivalent Al(1) atoms to form distorted SMgAl2Cr trigonal pyramids that share corners with six equivalent S(2)MgAl2Cr trigonal pyramids, corners with six equivalent S(1)MgAlCr2 trigonal pyramids,  an edgeedge with one S(2)MgAl2Cr trigonal pyramid, and edges with two equivalent S(1)MgAlCr2 trigonal pyramids.
MgCrAlS4 is Spinel-derived structured and crystallizes in the orthorhombic Imma space group. Mg(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form MgS4 tetrahedra that share corners with six equivalent Cr(1)S6 octahedra and corners with six equivalent Al(1)S6 octahedra. The corner-sharing octahedral tilt angles are 59°. Both Mg(1)-S(1) bond lengths are 2.45 Å. Both Mg(1)-S(2) bond lengths are 2.43 Å. Cr(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form CrS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Cr(1)S6 octahedra, and edges with four equivalent Al(1)S6 octahedra. Both Cr(1)-S(2) bond lengths are 2.44 Å. All Cr(1)-S(1) bond lengths are 2.43 Å. Al(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form AlS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Al(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Both Al(1)-S(1) bond lengths are 2.43 Å. All Al(1)-S(2) 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), two equivalent Cr(1), and one Al(1) atom to form distorted SMgAlCr2 trigonal pyramids that share corners with six equivalent S(2)MgAl2Cr trigonal pyramids, corners with six equivalent S(1)MgAlCr2 trigonal pyramids,  an edgeedge with one S(1)MgAlCr2 trigonal pyramid, and edges with two equivalent S(2)MgAl2Cr trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1), one Cr(1), and two equivalent Al(1) atoms to form distorted SMgAl2Cr trigonal pyramids that share corners with six equivalent S(2)MgAl2Cr trigonal pyramids, corners with six equivalent S(1)MgAlCr2 trigonal pyramids,  an edgeedge with one S(2)MgAl2Cr trigonal pyramid, and edges with two equivalent S(1)MgAlCr2 trigonal pyramids.