Al2O3 is Corundum-like structured and crystallizes in the trigonal R-3 space group. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent O(1) atoms to form a mixture of edge and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 43°. In the second Al site, Al(2) is bonded to six equivalent O(1) atoms to form a mixture of face and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. In the third Al site, Al(3) is bonded to six equivalent O(1) atoms to form a mixture of distorted edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 53°. O(1) is bonded to one Al(1), one Al(2), and two equivalent Al(3) atoms to form a mixture of edge and corner-sharing OAl4 trigonal pyramids.
Al2O3 is Corundum-like structured and crystallizes in the trigonal R-3 space group. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent O(1) atoms to form a mixture of edge and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 43°. All Al(1)-O(1) bond lengths are 1.91 Å. In the second Al site, Al(2) is bonded to six equivalent O(1) atoms to form a mixture of face and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. All Al(2)-O(1) bond lengths are 1.92 Å. In the third Al site, Al(3) is bonded to six equivalent O(1) atoms to form a mixture of distorted edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are three shorter (1.83 Å) and three longer (2.00 Å) Al(3)-O(1) bond lengths. O(1) is bonded to one Al(1), one Al(2), and two equivalent Al(3) atoms to form a mixture of edge and corner-sharing OAl4 trigonal pyramids.