data_global _amcsd_formula_title 'SrO*2(Al2O3)' loop_ _publ_author_name 'Boyko E R' 'Wisnyi L G' _journal_name_full 'Acta Crystallographica' _journal_volume 11 _journal_year 1958 _journal_page_first 444 _journal_page_last 445 _publ_section_title ; The optical properties and structures of CaO*2Al2O3 and SrO*2Al2O3 ; _database_code_amcsd 0009209 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Sr Al4 O7' _cell_length_a 13.04 _cell_length_b 9.01 _cell_length_c 5.55 _cell_angle_alpha 90 _cell_angle_beta 106.502 _cell_angle_gamma 90 _cell_volume 625.213 _exptl_crystal_density_diffrn 3.267 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Sr 0.00000 0.81000 0.25000 Al1 0.16900 0.08600 0.29500 Al2 0.12200 0.44100 0.25700 O1 0.00000 0.52600 0.25000 O2 0.11700 0.04800 0.54400 O3 0.12700 0.26000 0.17500 O4 0.18800 0.44700 0.59800