data_global _chemical_name_mineral 'Chrysoberyl' loop_ _publ_author_name 'Farrell E F' 'Fang J H' 'Newnham R E' _journal_name_full 'American Mineralogist' _journal_volume 48 _journal_year 1963 _journal_page_first 804 _journal_page_last 810 _publ_section_title ; Refinement of the chrysoberyl structure ; _database_code_amcsd 0000124 _chemical_formula_sum 'Al2 Be O4' _cell_length_a 9.404 _cell_length_b 5.476 _cell_length_c 4.427 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 227.974 _exptl_crystal_density_diffrn 3.699 _symmetry_space_group_name_H-M 'P n m a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' '1/2+x,y,1/2-z' '1/2-x,-y,1/2+z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Al1 0.00000 0.00000 0.00000 0.00092 Al2 0.27319 0.25000 -0.00595 0.00130 Be 0.09294 0.25000 0.43347 0.00191 O1 0.09051 0.25000 0.79016 0.00077 O2 0.43343 0.25000 0.24097 0.00286 O3 0.16318 0.01718 0.25850 0.00177