CuAlS2 crystallizes in the trigonal R3m space group. Cu(1) is bonded in a 5-coordinate geometry to one Al(1), one S(1), and three equivalent S(2) atoms. Al(1) is bonded in a 7-coordinate geometry to one Cu(1), three equivalent S(1), and three equivalent S(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Cu(1) and three equivalent Al(1) atoms to form distorted corner-sharing SAl3Cu tetrahedra. In the second S site, S(2) is bonded in a 6-coordinate geometry to three equivalent Cu(1) and three equivalent Al(1) atoms.
CuAlS2 crystallizes in the trigonal R3m space group. Cu(1) is bonded in a 5-coordinate geometry to one Al(1), one S(1), and three equivalent S(2) atoms. The Cu(1)-Al(1) bond length is 2.59 Å. The Cu(1)-S(1) bond length is 2.26 Å. All Cu(1)-S(2) bond lengths are 2.36 Å. Al(1) is bonded in a 7-coordinate geometry to one Cu(1), three equivalent S(1), and three equivalent S(2) atoms. All Al(1)-S(1) bond lengths are 2.39 Å. All Al(1)-S(2) bond lengths are 2.56 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Cu(1) and three equivalent Al(1) atoms to form distorted corner-sharing SAl3Cu tetrahedra. In the second S site, S(2) is bonded in a 6-coordinate geometry to three equivalent Cu(1) and three equivalent Al(1) atoms.