Materials Data on Al2O3 by Materials Project

Abstract

Al2O3 is Corundum-like structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six equivalent O2- atoms to form a mixture of edge and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 43°. All Al–O bond lengths are 1.93 Å. In the second Al3+ site, Al3+ is bonded to six equivalent O2- atoms to form a mixture of corner and face-sharing AlO6 octahedra. The corner-sharing octahedra tilt angles range from 43–53°. All Al–O bond lengths are 1.94 Å. In the third Al3+ site, Al3+ is bonded to six equivalent O2- atoms to form a mixture of distorted edge, corner, and face-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There is three shorter (1.85 Å) and three longer (2.03 Å) Al–O bond length. O2- is bonded to four Al3+ atoms to form a mixture of edge and corner-sharing OAl4 trigonal pyramids.