data_corundum

_chemical_name_systematic          'Aluminium oxide - $-alpha'
_chemical_name_mineral             'Corundum'
_chemical_formula_structural       'Al2 O3'
_chemical_formula_sum              'Al2 O3'

_publ_section_title                
;
Simultaneous structure and size-strain refinement by the Rietveld method
;
loop_
_publ_author_name                  
  'Lutterotti, L'
  'Scardi, P'
_journal_name_full                 'Journal of Applied Crystallography'
_journal_coden_ASTM                JACGAR
_journal_volume                    23
_journal_year                      1990
_journal_page_first                246
_journal_page_last                 252

_cell_length_a                     4.76050(5)
_cell_length_b                     4.76050(5)
_cell_length_c                     12.9956(2)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  120
_cell_volume                       255.1
_cell_formula_units_Z              6

_symmetry_space_group_name_H-M     'R -3 c H'
_symmetry_Int_Tables_number        167
_symmetry_cell_setting             trigonal

loop_
_symmetry_equiv_pos_as_xyz         
  'x,y,z'
  '-y,x-y,z'
  'y-x,-x,z'
  '-y,-x,1/2+z'
  'x,x-y,1/2+z'
  'y-x,y,1/2+z'
  '-x,-y,-z'
  'y,y-x,-z'
  'x-y,x,-z'
  'y,x,1/2-z'
  '-x,y-x,1/2-z'
  'x-y,-y,1/2-z'
  '1/3+x,2/3+y,2/3+z'
  '2/3+x,1/3+y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-y,2/3-x,1/6+z'
  '2/3-y,1/3-x,5/6+z'
  '1/3+x,2/3+x-y,1/6+z'
  '2/3+x,1/3+x-y,5/6+z'
  '1/3-x+y,2/3+y,1/6+z'
  '2/3-x+y,1/3+y,5/6+z'
  '1/3-x,2/3-y,2/3-z'
  '2/3-x,1/3-y,1/3-z'
  '1/3+y,2/3-x+y,2/3-z'
  '2/3+y,1/3-x+y,1/3-z'
  '1/3+x-y,2/3+x,2/3-z'
  '2/3+x-y,1/3+x,1/3-z'
  '1/3+y,2/3+x,1/6-z'
  '2/3+y,1/3+x,5/6-z'
  '1/3-x,2/3-x+y,1/6-z'
  '2/3-x,1/3-x+y,5/6-z'
  '1/3+x-y,2/3-y,1/6-z'
  '2/3+x-y,1/3-y,5/6-z'

loop_
_atom_type_symbol
_atom_type_oxidation_number
  Al3+   3.000
  O2-   -2.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Al1   Al3+  12 c 0. 0. 0.35216(3) 1.  0 d
  O1    O2-   18 e 0.30668(16) 0. 0.25 1.  0 d

loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_22
_atom_site_aniso_U_23
_atom_site_aniso_U_33
  Al1   0.0022(2) 0.0011 0. 0.0022(2) 0. 0.0012(3)
  O1    0.0021(71) 0.0017 0.00035 0.0034(149) 0.0007(54) 0.0019(3)

_refine_ls_R_factor_all            0.038



data_Al2O382504-ICSD

_chemical_name_systematic          'Aluminium oxide - $-theta'
_chemical_formula_structural       'Al2 O3'
_chemical_formula_sum              'Al2 O3'

_publ_section_title                
;
Structural studies of transition aluminas. Theta alumina
;
loop_
_publ_author_name                  
  'Husson, E'
  'Repelin, Y'
_journal_name_full                 
;
European Journal of Solid State Inorganic Chemistry
;
_journal_coden_ASTM                EJSCE5
_journal_volume                    33
_journal_year                      1996
_journal_page_first                1223
_journal_page_last                 1231

_cell_length_a                     11.795(5)
_cell_length_b                     2.91(1)
_cell_length_c                     5.621(7)
_cell_angle_alpha                  90
_cell_angle_beta                   103.79
_cell_angle_gamma                  90
_cell_volume                       187.4
_cell_formula_units_Z              4

_symmetry_space_group_name_H-M     'C 1 2/m 1'
_symmetry_Int_Tables_number        12
_symmetry_cell_setting             monoclinic

loop_
_symmetry_equiv_pos_as_xyz         
  'x,y,z'
  'x,-y,z'
  '-x,-y,-z'
  '-x,y,-z'
  '1/2+x,1/2+y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2-y,-z'
  '1/2-x,1/2+y,-z'

loop_
_atom_type_symbol
_atom_type_oxidation_number
  O2-   -2.000
  Al3+   3.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  O1    O2-    4 i 0.16268 0. 0.12276 1.  0 d
  O2    O2-    4 i 0.48945 0. 0.26127 1.  0 d
  O3    O2-    4 i 0.82995 0. 0.43863 1.  0 d
  Al1   Al3+   4 i 0.10134 0. 0.7944 1.  0 d
  Al2   Al3+   4 i 0.35235 0. 0.68739 1.  0 d

_refine_ls_R_factor_all            0.06