data_global _chemical_name_mineral 'Ferrosilite' loop_ _publ_author_name 'Smyth J R' _journal_name_full 'American Mineralogist' _journal_volume 58 _journal_year 1973 _journal_page_first 636 _journal_page_last 648 _publ_section_title ; An orthopyroxene structure up to 850 C T = 850 C ; _database_code_amcsd 0000367 _chemical_formula_sum 'Mg1.318 Fe.65 Ca.032 Si2 O6' _cell_length_a 18.546 _cell_length_b 9.081 _cell_length_c 5.298 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 892.269 _exptl_crystal_density_diffrn 3.302 _symmetry_space_group_name_H-M 'P b c a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,1/2+z' '-x,1/2+y,1/2-z' '1/2-x,1/2+y,z' '1/2+x,1/2-y,-z' '1/2+x,y,1/2-z' '1/2-x,-y,1/2+z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv Mg1 0.37460 0.65140 0.89190 0.49300 ? Fe1 0.37460 0.65140 0.89190 0.50700 ? Fe2 0.37670 0.48560 0.39050 0.14300 ? Mg2 0.37670 0.48560 0.39050 0.82500 ? Ca2 0.37670 0.48560 0.39050 0.03200 ? Sia 0.27200 0.33890 0.06440 1.00000 ? Sib 0.47500 0.33720 0.77840 1.00000 ? O1a 0.18410 0.33740 0.05500 1.00000 0.05281 O2a 0.31260 0.49500 0.07730 1.00000 0.03964 O3a 0.29870 0.23940 -0.17240 1.00000 0.03939 O1b 0.56210 0.34100 0.77460 1.00000 ? O2b 0.43480 0.48440 0.71330 1.00000 0.03901 O3b 0.45040 0.22280 0.55290 1.00000 0.04420 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 Mg1 0.00767 0.03848 0.02614 -0.00264 -0.00418 0.00141 Fe1 0.00767 0.03848 0.02614 -0.00264 -0.00418 0.00141 Fe2 0.02893 0.05172 0.03302 -0.00205 -0.01249 0.00405 Mg2 0.02893 0.05172 0.03302 -0.00205 -0.01249 0.00405 Ca2 0.02893 0.05172 0.03302 -0.00205 -0.01249 0.00405 Sia 0.01655 0.03534 0.01917 0.00085 -0.00299 -0.00058 Sib 0.01324 0.03467 0.02248 0.00555 -0.00005 0.00202 O1b 0.05245 0.06480 0.03295 0.01237 -0.01931 0.00417