data_global _chemical_name_mineral 'Forsterite' loop_ _publ_author_name 'Bragg W' 'Brown G' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 63 _journal_year 1926 _journal_page_first 538 _journal_page_last 556 _publ_section_title ; Die Struktur des Olivins. _cod_database_code 1010497 ; _database_code_amcsd 0017413 _chemical_formula_sum '(Mg1.8 Fe.2) Si O4' _cell_length_a 4.755 _cell_length_b 10.21 _cell_length_c 5.985 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 290.563 _exptl_crystal_density_diffrn 3.360 _symmetry_space_group_name_H-M 'P b n m' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,y,1/2-z' '-x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+y,1/2-z' '1/2-x,1/2+y,z' '1/2+x,1/2-y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Mg1 0.00000 0.00000 0.00000 0.90000 Fe1 0.00000 0.00000 0.00000 0.10000 Mg2 0.00000 0.28000 0.25000 0.90000 Fe2 0.00000 0.28000 0.25000 0.10000 Si1 0.40000 0.10000 0.25000 1.00000 O1 -0.25000 0.08000 0.25000 1.00000 O2 0.25000 0.42000 0.25000 1.00000 O3 0.25000 0.17000 0.00000 1.00000