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 = 500 C ; _database_code_amcsd 365 _chemical_formula_sum 'Si2 Mg.635 Fe1.332 Ca.032 O6' _cell_length_a 18.429 _cell_length_b 9.028 _cell_length_c 5.26 _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume 875.143 _exptl_crystal_density_diffrn 3.693 _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 Sia 0.2719 0.3392 0.0572 1.0 Sib 0.4745 0.3362 0.7874 1.0 Mg1 0.3752 0.6532 0.8841 0.576 Fe1 0.3752 0.6532 0.8841 0.423 Fe2 0.3772 0.485 0.3777 0.909 Mg2 0.3772 0.485 0.3777 0.059 Ca2 0.3772 0.485 0.3777 0.032 O1a 0.1841 0.3377 0.0522 1.0 O2a 0.312 0.4952 0.0684 1.0 O3a 0.3019 0.2374 -0.1778 1.0 O1b 0.5627 0.3384 0.7859 1.0 O2b 0.4345 0.4831 0.7031 1.0 O3b 0.4481 0.2112 0.5757 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 Sia 0.01273 0.01891 0.01919 -0.00059 0.00123 -0.00079 Sib 0.01721 0.01726 0.01587 0.00042 0.00059 0.00031 Mg1 0.01635 0.02226 0.01662 -0.00101 -0.00187 -0.00053 Fe1 0.01635 0.02226 0.01662 -0.00101 -0.00187 -0.00053 Fe2 0.02546 0.02808 0.02188 -0.00177 -0.008 0.00077 Mg2 0.02546 0.02808 0.02188 -0.00177 -0.008 0.00077 Ca2 0.02546 0.02808 0.02188 -0.00177 -0.008 0.00077 O1a 0.01462 0.02151 0.01238 0.00084 -0.00098 -0.00115 O2a 0.02564 0.01998 0.02499 0.00725 -0.0001 -0.00859 O3a 0.01617 0.0417 0.02572 -0.01197 -0.00044 0.00621 O1b 0.02288 0.02275 0.01341 -0.00084 -0.00398 -0.00075 O2b 0.02306 0.02126 0.01682 -0.00143 0.00486 -0.00383 O3b 0.0117 0.03658 0.02728 -0.00228 -0.0027 -0.00897