Materials Data on AlCuS2 by Materials Project
CuAlS2 is Ilmenite-like structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with nine equivalent AlS6 octahedra, corners with six equivalent CuS4 tetrahedra, and a faceface with one AlS6 octahedra. The corner-sharing octahedra tilt angles range from 51–61°. There are one shorter (2.26 Å) and three longer (2.36 Å) Cu–S bond lengths. Al3+ is bonded to six S2- atoms to form AlS6 octahedra that share corners with nine equivalent CuS4 tetrahedra, edges with six equivalent AlS6 octahedra, and a faceface with one CuS4 tetrahedra. There are three shorter (2.39 Å) and three longer (2.56 Å) Al–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to one Cu1+ and three equivalent Al3+ atoms to form distorted corner-sharing SAl3Cu tetrahedra. In the second S2- site, S2- is bonded in a 6-coordinate geometry to three equivalent Cu1+ and three equivalent Al3+ atoms.