data_global _chemical_name_mineral 'Hedenbergite' loop_ _publ_author_name 'Zhang L' 'Ahsbahs H' 'Hafner S S' 'Kutoglu A' _journal_name_full 'American Mineralogist' _journal_volume 82 _journal_year 1997 _journal_page_first 245 _journal_page_last 258 _publ_section_title ; Single-crystal compression and crystal structure of clinopyroxene up to 10 GPa Sample: at P = 1.1 GPa Note: cell parameters obtained by linear regression ; _database_code_amcsd 0001862 _chemical_formula_sum 'Ca Fe Si2 O6' _cell_length_a 9.810 _cell_length_b 8.985 _cell_length_c 5.224 _cell_angle_alpha 90 _cell_angle_beta 104.58 _cell_angle_gamma 90 _cell_volume 445.630 _exptl_crystal_density_diffrn 3.698 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Ca 0.00000 0.30040 0.25000 0.00861 Fe 0.00000 0.90764 0.25000 0.00595 Si 0.28782 0.09305 0.23216 0.00545 O1 0.11951 0.09068 0.15267 0.00722 O2 0.36247 0.24747 0.32409 0.01115 O3 0.35052 0.02100 0.99087 0.00887