data_global _chemical_name_mineral 'Corundum' loop_ _publ_author_name 'Lutterotti L' 'Scardi P' _journal_name_full 'Journal of Applied Crystallography' _journal_volume 23 _journal_year 1990 _journal_page_first 246 _journal_page_last 252 _publ_section_title ; Simultaneous structure and size-strain refinement by the Rietveld method _cod_database_code 1000032 ; _database_code_amcsd 0012859 _chemical_formula_sum 'Al2 O3' _cell_length_a 4.76050 _cell_length_b 4.76050 _cell_length_c 12.9956 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 255.054 _exptl_crystal_density_diffrn 3.983 _symmetry_space_group_name_H-M 'R -3 c' loop_ _space_group_symop_operation_xyz 'x,y,z' '2/3+x,1/3+y,1/3+z' '1/3+x,2/3+y,2/3+z' 'x,x-y,1/2+z' '2/3+x,1/3+x-y,5/6+z' '1/3+x,2/3+x-y,1/6+z' 'y,x,1/2-z' '2/3+y,1/3+x,5/6-z' '1/3+y,2/3+x,1/6-z' '-x+y,y,1/2+z' '2/3-x+y,1/3+y,5/6+z' '1/3-x+y,2/3+y,1/6+z' '-x,-x+y,1/2-z' '2/3-x,1/3-x+y,5/6-z' '1/3-x,2/3-x+y,1/6-z' '-y,-x,1/2+z' '2/3-y,1/3-x,5/6+z' '1/3-y,2/3-x,1/6+z' 'x-y,-y,1/2-z' '2/3+x-y,1/3-y,5/6-z' '1/3+x-y,2/3-y,1/6-z' 'y,-x+y,-z' '2/3+y,1/3-x+y,1/3-z' '1/3+y,2/3-x+y,2/3-z' '-x+y,-x,z' '2/3-x+y,1/3-x,1/3+z' '1/3-x+y,2/3-x,2/3+z' '-x,-y,-z' '2/3-x,1/3-y,1/3-z' '1/3-x,2/3-y,2/3-z' '-y,x-y,z' '2/3-y,1/3+x-y,1/3+z' '1/3-y,2/3+x-y,2/3+z' 'x-y,x,-z' '2/3+x-y,1/3+x,1/3-z' '1/3+x-y,2/3+x,2/3-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Al 0.00000 0.00000 0.35216 O 0.30668 0.00000 0.25000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Al 0.00220 0.00220 0.00120 0.00110 0.00000 0.00000 O 0.00210 0.00340 0.00190 0.00170 0.00035 0.00070