The crystal structure described by 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. is represented by the CIF file [CIF]
data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.798
_cell_length_b   5.252
_cell_length_c   4.798
_cell_angle_alpha   117.175
_cell_angle_beta   60.000
_cell_angle_gamma   117.175
_symmetry_Int_Tables_number   1
_cell_volume   88.956
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Al  Al0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.500  0.500  1.0
  Al  Al2  1  0.307  0.920  0.307  1.0
  Al  Al3  1  0.693  0.080  0.693  1.0
  O  O4  1  0.280  0.776  0.604  1.0
  O  O5  1  0.396  0.224  0.108  1.0
  O  O6  1  0.108  0.224  0.720  1.0
  O  O7  1  0.892  0.776  0.280  1.0
  O  O8  1  0.604  0.776  0.892  1.0
  O  O9  1  0.720  0.224  0.396  1.0
[/CIF]
.
The crystal structure described by 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. is represented by the CIF file [CIF]
data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.798
_cell_length_b   5.252
_cell_length_c   4.798
_cell_angle_alpha   117.175
_cell_angle_beta   60.000
_cell_angle_gamma   117.175
_symmetry_Int_Tables_number   1
_cell_volume   88.956
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Al  Al0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.500  0.500  1.0
  Al  Al2  1  0.307  0.920  0.307  1.0
  Al  Al3  1  0.693  0.080  0.693  1.0
  O  O4  1  0.280  0.776  0.604  1.0
  O  O5  1  0.396  0.224  0.108  1.0
  O  O6  1  0.108  0.224  0.720  1.0
  O  O7  1  0.892  0.776  0.280  1.0
  O  O8  1  0.604  0.776  0.892  1.0
  O  O9  1  0.720  0.224  0.396  1.0
[/CIF]
.