data_global _chemical_name_mineral 'Forsterite' loop_ _publ_author_name 'Brown G E' 'Prewitt C T' _journal_name_full 'American Mineralogist' _journal_volume 58 _journal_year 1973 _journal_page_first 577 _journal_page_last 587 _publ_section_title ; High-temperature crystal chemistry of hortonolite sample #12052 T = 375 C Note: variety hortonolite ; _database_code_amcsd 326 _chemical_formula_sum 'Si Mg1.38 Fe.61 Ca.01 O4' _cell_length_a 4.795 _cell_length_b 10.337 _cell_length_c 6.045 _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume 299.626 _exptl_crystal_density_diffrn 3.549 _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 Si 0.4279 0.0952 0.25 1.0 Mg1 0.0 0.0 0.0 0.677 Fe1 0.0 0.0 0.0 0.323 Mg2 0.9886 0.2788 0.25 0.703 Fe2 0.9886 0.2788 0.25 0.287 Ca2 0.9886 0.2788 0.25 0.01 O1 0.7654 0.0919 0.25 1.0 O2 0.2177 0.4496 0.25 1.0 O3 0.2816 0.1636 0.0348 1.0 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Si 0.00606 0.0065 0.00926 0.00025 0.0 0.0 Mg1 0.00978 0.01353 0.00981 -0.00025 -0.00147 -0.00317 Fe1 0.00978 0.01353 0.00981 -0.00025 -0.00147 -0.00317 Mg2 0.01305 0.00704 0.01111 0.00025 0.0 0.0 Fe2 0.01305 0.00704 0.01111 0.00025 0.0 0.0 Ca2 0.01305 0.00704 0.01111 0.00025 0.0 0.0 O1 0.00559 0.01462 0.01185 0.00151 0.0 0.0 O2 0.01293 0.0065 0.01296 -0.00075 0.0 0.0 O3 0.01188 0.01299 0.01185 0.0005 -0.00073 0.00348