data_Al2O3 _audit_creation_date 102-05-16 _chemical_name_systematic 'Aluminium oxide' _chemical_name_mineral 'Corundum' _chemical_formula_structural 'Al2 O3' _chemical_formula_sum 'Al2 O3' _publ_section_title ; Ruby structure peculiarities derived from X-ray data. Localization of chromium atoms and electron deformation density ; loop_ _publ_author_name 'Tsirelson, V G' 'Antipin, M Y' 'Gerr, R G' 'Ozerov, R P' 'Struchkov, Y T' _journal_name_full ; Physica Status Solidi, Sectio A: Applied Research ; _journal_coden_ASTM PSSABA _journal_volume 87 _journal_year 1985 _journal_page_first 425 _journal_page_last 433 _cell_length_a 4.7606(5) _cell_length_b 4.7606(5) _cell_length_c 12.994(1) _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 255.0 _cell_formula_units_Z 6 _symmetry_space_group_name_H-M 'R -3 c' _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 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- 18 e 0.69365(3) 0. 0.25 1. 0 d Al1 Al3+ 12 c 0. 0. 0.35217(1) 1. 0 d _refine_ls_R_factor_all 0.063