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 II ; _database_code_amcsd 0000281 _chemical_compound_source 'hypothetical' _chemical_formula_sum 'Si Mg2 O4' _cell_length_a 10.05 _cell_length_b 5.75 _cell_length_c 4.87 _cell_angle_alpha 90 _cell_angle_beta 90.0 _cell_angle_gamma 90 _cell_volume 281.425 _exptl_crystal_density_diffrn 3.321 _symmetry_space_group_name_H-M 'C 1 2/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,z' '1/2+x,1/2-y,z' '-x,y,-z' '1/2-x,1/2+y,-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 Si 0.33300 0.00000 0.89870 Mg1 0.00000 0.00000 0.00000 Mg2 0.50000 0.00000 0.50000 Mg3 0.25000 0.25000 0.50000 O1 0.81940 0.00000 0.22200 O2 0.33410 0.00000 0.23530 O3 0.09080 0.27030 0.22530