Materials Data on Al5HO8 by Materials Project

Abstract

HAl5O8 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with three equivalent AlO4 tetrahedra, and edges with five AlO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Al–O bond distances ranging from 1.86–1.97 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six equivalent AlO6 octahedra, corners with three equivalent AlO4 tetrahedra, and edges with three equivalent AlO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There is three shorter (1.87 Å) and three longer (2.05 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–62°. There is three shorter (1.81 Å) and one longer (1.83 Å) Al–O bond length. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Al3+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Al3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Al3+ atoms.