data_Al2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.85
_cell_length_b   4.85
_cell_length_c   9.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al2O3
_chemical_formula_sum   'Al8 O12'
_cell_volume   184.82
_cell_formula_units_Z   4
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  0.0  0.8  0.75  1.0
  Al  Al1  1  0.0  0.8  0.27  1.0
  Al  Al2  1  0.0  0.0  0.0  1.0
  Al  Al3  1  0.0  0.0  0.54  1.0
  Al  Al4  1  0.0  0.8  0.88  1.0
  Al  Al5  1  0.42  0.4  0.34  1.0
  Al  Al6  1  0.42  0.4  0.81  1.0
  Al  Al7  1  0.42  0.4  0.21  1.0
  O  O8  1  0.51  0.84  0.02  1.0
  O  O9  1  0.13  0.71  0.56  1.0
  O  O10  1  0.29  0.49  0.53  1.0
  O  O11  1  0.91  0.36  0.07  1.0
  O  O12  1  0.71  0.49  0.02  1.0
  O  O13  1  0.94  0.36  0.56  1.0
  O  O14  1  0.22  0.06  0.53  1.0
  O  O15  1  0.64  0.13  0.07  1.0
  O  O16  1  0.49  0.84  0.53  1.0
  O  O17  1  0.72  0.71  0.07  1.0
  O  O18  1  0.78  0.06  0.02  1.0
  O  O19  1  0.2  0.13  0.56  1.0

data_Al2O3
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.85
_cell_length_b   4.85
_cell_length_c   9.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al2O3
_chemical_formula_sum   'Al8 O12'
_cell_volume   184.82
_cell_formula_units_Z   4
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  0.0  0.0  0.0  1.0
  Al  Al1  1  0.0  0.0  0.54  1.0
  Al  Al2  1  0.0  0.8  0.27  1.0
  Al  Al3  1  0.0  0.8  0.75  1.0
  Al  Al4  1  0.0  0.8  0.88  1.0
  Al  Al5  1  0.42  0.4  0.21  1.0
  Al  Al6  1  0.42  0.4  0.34  1.0
  Al  Al7  1  0.42  0.4  0.81  1.0
  O  O8  1  0.13  0.71  0.56  1.0
  O  O9  1  0.2  0.13  0.56  1.0
  O  O10  1  0.22  0.06  0.53  1.0
  O  O11  1  0.29  0.49  0.53  1.0
  O  O12  1  0.49  0.84  0.53  1.0
  O  O13  1  0.51  0.84  0.02  1.0
  O  O14  1  0.64  0.13  0.07  1.0
  O  O15  1  0.71  0.49  0.02  1.0
  O  O16  1  0.72  0.71  0.07  1.0
  O  O17  1  0.78  0.06  0.02  1.0
  O  O18  1  0.91  0.36  0.07  1.0
  O  O19  1  0.94  0.36  0.56  1.0

Al Al Al Al Al Al Al Al O O O O O O O O O O O O
Al Al Al Al Al Al Al Al O O O O O O O O O O O O 0 4 o o o 0 6 o + o 0 6 - o o 1 17 - o o 1 12 - o o 1 7 - o o 1 7 o + o 1 5 - o o 1 5 o + o 1 2 o + o 1 3 o + o 1 11 - o o 1 9 o o o 1 19 o + o 1 14 o + o 2 17 - - o 2 18 - o o 2 4 o - - 2 6 o o - 3 14 o o o 3 19 o o o 3 9 o - o 4 6 o + o 4 6 - o o 5 7 o o o 6 19 o o o 6 14 o o o 6 10 o o o 6 8 o o + 6 17 o o + 6 12 o o + 8 15 o + o 8 18 o + o 9 13 - o o 9 14 o + o 9 10 o o o 9 16 o o o 10 13 - o o 10 19 o o o 10 16 o o o 11 15 o o o 11 18 o o o 12 17 o o o 14 19 o o o 15 18 o o o 
Al2O3 crystallizes in the triclinic P1 space group. There are eight inequivalent Al sites. In the first Al site, Al(1) is bonded in a 1-coordinate geometry to one Al(5) and one O(2) atom. The Al(1)-Al(5) bond length is 1.20 Å. The Al(1)-O(2) bond length is 1.95 Å. In the second Al site, Al(2) is bonded in a single-bond geometry to one O(10) atom. The Al(2)-O(10) bond length is 2.20 Å. In the third Al site, Al(3) is bonded in a 2-coordinate geometry to one Al(5), one O(10), and one O(11) atom. The Al(3)-Al(5) bond length is 1.46 Å. The Al(3)-O(10) bond length is 1.53 Å. The Al(3)-O(11) bond length is 1.26 Å. In the fourth Al site, Al(4) is bonded in a 2-coordinate geometry to one O(12), one O(2), one O(6), one O(7), and one O(9) atom. The Al(4)-O(12) bond length is 0.88 Å. The Al(4)-O(2) bond length is 1.83 Å. The Al(4)-O(6) bond length is 1.91 Å. The Al(4)-O(7) bond length is 0.97 Å. The Al(4)-O(9) bond length is 2.22 Å. In the fifth Al site, Al(5) is bonded in a 3-coordinate geometry to one Al(1), one Al(3), and one O(5) atom. The Al(5)-O(5) bond length is 1.91 Å. In the sixth Al site, Al(6) is bonded in a 3-coordinate geometry to one Al(8), one O(3), and one O(7) atom. The Al(6)-Al(8) bond length is 1.20 Å. The Al(6)-O(3) bond length is 1.95 Å. The Al(6)-O(7) bond length is 2.22 Å. In the seventh Al site, Al(7) is bonded in a single-bond geometry to one O(5) atom. The Al(7)-O(5) bond length is 2.20 Å. In the eighth Al site, Al(8) is bonded in a 4-coordinate geometry to one Al(6), one O(10), one O(5), and one O(8) atom. The Al(8)-O(10) bond length is 1.91 Å. The Al(8)-O(5) bond length is 2.10 Å. The Al(8)-O(8) bond length is 2.39 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one O(10), one O(11), and one O(8) atom. The O(1)-O(10) bond length is 1.50 Å. The O(1)-O(11) bond length is 1.19 Å. The O(1)-O(8) bond length is 1.32 Å. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Al(1), one Al(4), one O(3), one O(6), one O(7), and one O(9) atom. The O(2)-O(3) bond length is 1.62 Å. The O(2)-O(6) bond length is 1.47 Å. The O(2)-O(7) bond length is 1.59 Å. The O(2)-O(9) bond length is 1.54 Å. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Al(6), one O(2), one O(6), and one O(9) atom. The O(3)-O(6) bond length is 1.54 Å. The O(3)-O(9) bond length is 1.47 Å. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one O(11), one O(5), and one O(8) atom. The O(4)-O(11) bond length is 1.32 Å. The O(4)-O(5) bond length is 1.50 Å. The O(4)-O(8) bond length is 1.19 Å. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Al(5), one Al(7), one Al(8), one O(10), one O(4), and one O(8) atom. The O(5)-O(10) bond length is 1.13 Å. The O(5)-O(8) bond length is 1.67 Å. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Al(4), one O(2), and one O(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Al(4), one Al(6), one O(12), and one O(2) atom. The O(7)-O(12) bond length is 0.50 Å. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Al(8), one O(1), one O(11), one O(4), and one O(5) atom. The O(8)-O(11) bond length is 0.99 Å. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Al(4), one O(2), and one O(3) atom. In the tenth O site, O(10) is bonded in a 1-coordinate geometry to one Al(2), one Al(3), one Al(8), one O(1), and one O(5) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Al(3), one O(1), one O(4), and one O(8) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Al(4) and one O(7) atom.