Materials Data on Al5CuS8 by Materials Project
CuAl5S8 is Spinel-like structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Cu1+ is bonded to four equivalent S2- atoms to form CuS4 tetrahedra that share corners with twelve equivalent AlS6 octahedra. The corner-sharing octahedral tilt angles are 55°. All Cu–S bond lengths are 2.29 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six S2- atoms to form AlS6 octahedra that share corners with three equivalent CuS4 tetrahedra, corners with three equivalent AlS4 tetrahedra, and edges with six equivalent AlS6 octahedra. There are three shorter (2.36 Å) and three longer (2.50 Å) Al–S bond lengths. In the second Al3+ site, Al3+ is bonded to four equivalent S2- atoms to form corner-sharing AlS4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. All Al–S bond lengths are 2.31 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three equivalent Al3+ atoms. In the second S2- site, S2- is bonded to four Al3+ atoms to form a mixture of distorted corner and edge-sharing SAl4 tetrahedra.