data_global _chemical_name_mineral 'Wadsleyite' loop_ _publ_author_name 'Baur W H' _journal_name_full 'American Mineralogist' _journal_volume 57 _journal_year 1972 _journal_page_first 709 _journal_page_last 731 _publ_section_title ; Computer-simulated crystal structures of observed and hypothetical Mg2SiO4 Polymorphs of low and high density ; _database_code_amcsd 0000277 _chemical_compound_source 'hypothetical' _chemical_formula_sum 'Si Mg2 O4' _cell_length_a 8.16 _cell_length_b 11.68 _cell_length_c 5.71 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 544.213 _exptl_crystal_density_diffrn 3.434 _symmetry_space_group_name_H-M 'I b m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'x,y,1/2-z' '1/2+x,1/2+y,-z' '-x,-y,1/2+z' '1/2-x,1/2-y,+z' 'x,-y,z' '1/2+x,1/2-y,1/2+z' '-x,y,-z' '1/2-x,1/2+y,1/2-z' '-x,y,1/2+z' '1/2-x,1/2+y,+z' 'x,-y,1/2-z' '1/2+x,1/2-y,-z' '-x,-y,-z' '1/2-x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Si 0.13030 0.12550 0.25000 Mg1 0.22970 0.00000 0.75000 Mg2 0.25000 0.25000 0.75000 Mg3 0.00000 0.37010 0.00000 O1 0.03000 0.00000 0.25000 O2 0.47990 0.00000 0.75000 O3 0.00400 0.23480 0.25000 O4 0.25570 0.37510 0.01680