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 at T = 24 C Note: variety hortonolite ; _database_code_amcsd 0000325 _chemical_formula_sum 'Si Mg1.38 Fe.61 Ca.01 O4' _cell_length_a 4.785 _cell_length_b 10.298 _cell_length_c 6.028 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 297.035 _exptl_crystal_density_diffrn 3.580 _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 0.42760 0.09520 0.25000 1.00000 Mg1 0.00000 0.00000 0.00000 0.67500 Fe1 0.00000 0.00000 0.00000 0.32500 Mg2 0.98770 0.27830 0.25000 0.70500 Fe2 0.98770 0.27830 0.25000 0.28500 Ca2 0.98770 0.27830 0.25000 0.01000 O1 0.76590 0.09200 0.25000 1.00000 O2 0.21810 0.44930 0.25000 1.00000 O3 0.28090 0.16370 0.03400 1.00000 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 0.00313 0.00269 0.00534 0.00025 0.00000 0.00000 Mg1 0.00418 0.00484 0.00479 0.00000 -0.00058 -0.00126 Fe1 0.00418 0.00484 0.00479 0.00000 -0.00058 -0.00126 Mg2 0.00615 0.00161 0.00515 0.00025 0.00000 0.00000 Fe2 0.00615 0.00161 0.00515 0.00025 0.00000 0.00000 Ca2 0.00615 0.00161 0.00515 0.00025 0.00000 0.00000 O1 0.00418 0.00484 0.00755 0.00025 0.00000 0.00000 O2 0.00661 0.00269 0.00663 0.00050 0.00000 0.00000 O3 0.00626 0.00591 0.00847 0.00075 -0.00015 0.00189