The material described by Al2O3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form a mixture of corner and edge-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the second Al site, Al(2) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to two equivalent Al(1) and two equivalent Al(2) atoms. In the second O site, O(2) is bonded to two equivalent Al(1) and two equivalent Al(2) atoms to form corner-sharing OAl4 tetrahedra. is represented by the CIF file [CIF]
data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.672
_cell_length_b   4.672
_cell_length_c   7.045
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.746
_symmetry_Int_Tables_number   1
_cell_volume   84.338
_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  0.246  0.754  0.250  1.0
  Al  Al2  1  0.754  0.246  0.750  1.0
  Al  Al3  1  0.000  0.000  0.500  1.0
  O  O4  1  0.633  0.367  0.420  1.0
  O  O5  1  0.893  0.107  0.250  1.0
  O  O6  1  0.367  0.633  0.580  1.0
  O  O7  1  0.367  0.633  0.920  1.0
  O  O8  1  0.107  0.893  0.750  1.0
  O  O9  1  0.633  0.367  0.080  1.0
[/CIF]
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The material described by Al2O3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form a mixture of corner and edge-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the second Al site, Al(2) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to two equivalent Al(1) and two equivalent Al(2) atoms. In the second O site, O(2) is bonded to two equivalent Al(1) and two equivalent Al(2) atoms to form corner-sharing OAl4 tetrahedra. is represented by the CIF file [CIF]
data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.672
_cell_length_b   4.672
_cell_length_c   7.045
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.746
_symmetry_Int_Tables_number   1
_cell_volume   84.338
_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  0.246  0.754  0.250  1.0
  Al  Al2  1  0.754  0.246  0.750  1.0
  Al  Al3  1  0.000  0.000  0.500  1.0
  O  O4  1  0.633  0.367  0.420  1.0
  O  O5  1  0.893  0.107  0.250  1.0
  O  O6  1  0.367  0.633  0.580  1.0
  O  O7  1  0.367  0.633  0.920  1.0
  O  O8  1  0.107  0.893  0.750  1.0
  O  O9  1  0.633  0.367  0.080  1.0
[/CIF]
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