The material described by Al2O3 is Corundum-like structured and crystallizes in the orthorhombic Pbca space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of face, corner, and edge-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-61°. In the second Al site, Al(2) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of face, corner, and edge-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-70°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Al(1) and three equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OAl4 tetrahedra. In the second O site, O(2) is bonded to one Al(2) and three equivalent Al(1) atoms to form a mixture of distorted corner and edge-sharing OAl4 trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Al(1) and two equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OAl4 trigonal pyramids. is represented by the CIF file [CIF]
data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.778
_cell_length_b   5.034
_cell_length_c   13.938
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   335.250
_cell_formula_units_Z   8
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  1.000  0.184  0.073  1.0
  Al  Al1  1  0.998  0.747  0.178  1.0
  Al  Al2  1  1.000  0.316  0.573  1.0
  Al  Al3  1  0.998  0.753  0.678  1.0
  Al  Al4  1  0.502  0.247  0.178  1.0
  Al  Al5  1  0.502  0.253  0.678  1.0
  Al  Al6  1  0.500  0.684  0.073  1.0
  Al  Al7  1  0.500  0.816  0.573  1.0
  Al  Al8  1  0.500  0.184  0.427  1.0
  Al  Al9  1  0.500  0.316  0.927  1.0
  Al  Al10  1  0.498  0.747  0.322  1.0
  Al  Al11  1  0.498  0.753  0.822  1.0
  Al  Al12  1  0.000  0.684  0.427  1.0
  Al  Al13  1  0.002  0.247  0.322  1.0
  Al  Al14  1  0.002  0.253  0.822  1.0
  Al  Al15  1  0.000  0.816  0.927  1.0
  O  O16  1  0.143  0.118  0.203  1.0
  O  O17  1  0.143  0.382  0.703  1.0
  O  O18  1  0.153  0.836  0.050  1.0
  O  O19  1  0.153  0.664  0.550  1.0
  O  O20  1  0.198  0.963  0.377  1.0
  O  O21  1  0.198  0.537  0.877  1.0
  O  O22  1  0.302  0.463  0.377  1.0
  O  O23  1  0.302  0.037  0.877  1.0
  O  O24  1  0.347  0.164  0.550  1.0
  O  O25  1  0.347  0.336  0.050  1.0
  O  O26  1  0.357  0.618  0.203  1.0
  O  O27  1  0.357  0.882  0.703  1.0
  O  O28  1  0.643  0.118  0.297  1.0
  O  O29  1  0.643  0.382  0.797  1.0
  O  O30  1  0.653  0.836  0.450  1.0
  O  O31  1  0.653  0.664  0.950  1.0
  O  O32  1  0.698  0.537  0.623  1.0
  O  O33  1  0.698  0.963  0.123  1.0
  O  O34  1  0.802  0.463  0.123  1.0
  O  O35  1  0.802  0.037  0.623  1.0
  O  O36  1  0.847  0.336  0.450  1.0
  O  O37  1  0.847  0.164  0.950  1.0
  O  O38  1  0.857  0.882  0.797  1.0
  O  O39  1  0.857  0.618  0.297  1.0
[/CIF]
.
The material described by Al2O3 is Corundum-like structured and crystallizes in the orthorhombic Pbca space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of face, corner, and edge-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-61°. In the second Al site, Al(2) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of face, corner, and edge-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-70°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Al(1) and three equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OAl4 tetrahedra. In the second O site, O(2) is bonded to one Al(2) and three equivalent Al(1) atoms to form a mixture of distorted corner and edge-sharing OAl4 trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Al(1) and two equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OAl4 trigonal pyramids. is represented by the CIF file [CIF]
data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.778
_cell_length_b   5.034
_cell_length_c   13.938
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   335.250
_cell_formula_units_Z   8
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  1.000  0.184  0.073  1.0
  Al  Al1  1  0.998  0.747  0.178  1.0
  Al  Al2  1  1.000  0.316  0.573  1.0
  Al  Al3  1  0.998  0.753  0.678  1.0
  Al  Al4  1  0.502  0.247  0.178  1.0
  Al  Al5  1  0.502  0.253  0.678  1.0
  Al  Al6  1  0.500  0.684  0.073  1.0
  Al  Al7  1  0.500  0.816  0.573  1.0
  Al  Al8  1  0.500  0.184  0.427  1.0
  Al  Al9  1  0.500  0.316  0.927  1.0
  Al  Al10  1  0.498  0.747  0.322  1.0
  Al  Al11  1  0.498  0.753  0.822  1.0
  Al  Al12  1  0.000  0.684  0.427  1.0
  Al  Al13  1  0.002  0.247  0.322  1.0
  Al  Al14  1  0.002  0.253  0.822  1.0
  Al  Al15  1  0.000  0.816  0.927  1.0
  O  O16  1  0.143  0.118  0.203  1.0
  O  O17  1  0.143  0.382  0.703  1.0
  O  O18  1  0.153  0.836  0.050  1.0
  O  O19  1  0.153  0.664  0.550  1.0
  O  O20  1  0.198  0.963  0.377  1.0
  O  O21  1  0.198  0.537  0.877  1.0
  O  O22  1  0.302  0.463  0.377  1.0
  O  O23  1  0.302  0.037  0.877  1.0
  O  O24  1  0.347  0.164  0.550  1.0
  O  O25  1  0.347  0.336  0.050  1.0
  O  O26  1  0.357  0.618  0.203  1.0
  O  O27  1  0.357  0.882  0.703  1.0
  O  O28  1  0.643  0.118  0.297  1.0
  O  O29  1  0.643  0.382  0.797  1.0
  O  O30  1  0.653  0.836  0.450  1.0
  O  O31  1  0.653  0.664  0.950  1.0
  O  O32  1  0.698  0.537  0.623  1.0
  O  O33  1  0.698  0.963  0.123  1.0
  O  O34  1  0.802  0.463  0.123  1.0
  O  O35  1  0.802  0.037  0.623  1.0
  O  O36  1  0.847  0.336  0.450  1.0
  O  O37  1  0.847  0.164  0.950  1.0
  O  O38  1  0.857  0.882  0.797  1.0
  O  O39  1  0.857  0.618  0.297  1.0
[/CIF]
.