ZnAl2S4 crystallizes in the monoclinic Pm space group. Zn(1) is bonded to one S(1), one S(4), and two equivalent S(3) atoms to form ZnS4 tetrahedra that share corners with two equivalent Zn(1)S4 tetrahedra, corners with four equivalent Al(1)S4 tetrahedra, and corners with four equivalent Al(2)S4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one S(2), one S(3), and two equivalent S(4) atoms to form AlS4 tetrahedra that share corners with two equivalent Al(1)S4 tetrahedra, corners with two equivalent Al(2)S4 tetrahedra, and corners with four equivalent Zn(1)S4 tetrahedra. In the second Al site, Al(2) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form AlS4 tetrahedra that share corners with two equivalent Al(1)S4 tetrahedra, corners with two equivalent Al(2)S4 tetrahedra, and corners with four equivalent Zn(1)S4 tetrahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one Zn(1) and two equivalent Al(2) atoms. In the second S site, S(2) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. In the third S site, S(3) is bonded to two equivalent Zn(1), one Al(1), and one Al(2) atom to form corner-sharing SAl2Zn2 tetrahedra. In the fourth S site, S(4) is bonded in a trigonal non-coplanar geometry to one Zn(1) and two equivalent Al(1) atoms.
ZnAl2S4 crystallizes in the monoclinic Pm space group. Zn(1) is bonded to one S(1), one S(4), and two equivalent S(3) atoms to form ZnS4 tetrahedra that share corners with two equivalent Zn(1)S4 tetrahedra, corners with four equivalent Al(1)S4 tetrahedra, and corners with four equivalent Al(2)S4 tetrahedra. The Zn(1)-S(1) bond length is 2.34 Å. The Zn(1)-S(4) bond length is 2.35 Å. Both Zn(1)-S(3) bond lengths are 2.40 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one S(2), one S(3), and two equivalent S(4) atoms to form AlS4 tetrahedra that share corners with two equivalent Al(1)S4 tetrahedra, corners with two equivalent Al(2)S4 tetrahedra, and corners with four equivalent Zn(1)S4 tetrahedra. The Al(1)-S(2) bond length is 2.19 Å. The Al(1)-S(3) bond length is 2.37 Å. Both Al(1)-S(4) bond lengths are 2.31 Å. In the second Al site, Al(2) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form AlS4 tetrahedra that share corners with two equivalent Al(1)S4 tetrahedra, corners with two equivalent Al(2)S4 tetrahedra, and corners with four equivalent Zn(1)S4 tetrahedra. The Al(2)-S(2) bond length is 2.18 Å. The Al(2)-S(3) bond length is 2.39 Å. Both Al(2)-S(1) bond lengths are 2.30 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one Zn(1) and two equivalent Al(2) atoms. In the second S site, S(2) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. In the third S site, S(3) is bonded to two equivalent Zn(1), one Al(1), and one Al(2) atom to form corner-sharing SAl2Zn2 tetrahedra. In the fourth S site, S(4) is bonded in a trigonal non-coplanar geometry to one Zn(1) and two equivalent Al(1) atoms.