Materials Data on Al5Se8 by Materials Project
Al5Se8 crystallizes in the cubic F-43m space group. The structure is three-dimensional. there are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six Se+1.88- atoms to form AlSe6 octahedra that share corners with three equivalent AlSe4 tetrahedra and edges with six equivalent AlSe6 octahedra. There are three shorter (2.51 Å) and three longer (2.66 Å) Al–Se bond lengths. In the second Al3+ site, Al3+ is bonded to four equivalent Se+1.88- atoms to form corner-sharing AlSe4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. All Al–Se bond lengths are 2.45 Å. There are two inequivalent Se+1.88- sites. In the first Se+1.88- site, Se+1.88- is bonded to four Al3+ atoms to form a mixture of distorted edge and corner-sharing SeAl4 tetrahedra. In the second Se+1.88- site, Se+1.88- is bonded in a distorted T-shaped geometry to three equivalent Al3+ atoms.