data_global _amcsd_formula_title 'Mg2SiO4' 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 Model I ; _database_code_amcsd 280 _chemical_compound_source 'hypothetical' _chemical_formula_sum 'Si Mg2 O4' _cell_length_a 10.11 _cell_length_b 5.77 _cell_length_c 4.7 _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume 274.173 _exptl_crystal_density_diffrn 3.408 _symmetry_space_group_name_H-M 'P 1 2/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,-y,z' '-x,y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Si1 0.842 0.5 0.8752 Si2 0.3226 0.0 0.8824 Mg1 0.5 0.5 0.0 Mg2 0.0 0.0 0.5 Mg3 0.0 0.5 0.5 Mg4 0.5 0.0 0.5 Mg5 0.2482 0.2527 0.499 O1 0.3154 0.5 0.2105 O2 0.1642 0.5 0.7757 O3 0.8305 0.0 0.2334 O4 0.333 0.0 0.2309 O5 0.0851 0.2601 0.2287 O6 0.5932 0.2281 0.221