Materials Data on Al5O8 by Materials Project

Abstract

Al5O8 is beta indium sulfide-like structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. there are two inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with three equivalent AlO4 tetrahedra and edges with six equivalent AlO6 octahedra. There is three shorter (1.87 Å) and three longer (1.96 Å) Al–O bond length. In the second Al site, Al is bonded to four equivalent O atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedral tilt angles are 58°. All Al–O bond lengths are 1.84 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted T-shaped geometry to three equivalent Al atoms. In the second O site, O is bonded to four Al atoms to form a mixture of distorted corner and edge-sharing OAl4 trigonal pyramids.