data_global _chemical_name_mineral 'Hedenbergite' loop_ _publ_author_name 'Redhammer G J' 'Amthauer G' 'Roth G' 'Tippelt G' 'Lottermoser W' _journal_name_full 'American Mineralogist' _journal_volume 91 _journal_year 2006 _journal_page_first 1271 _journal_page_last 1292 _publ_section_title ; Single crystal X-ray diffraction and temperature dependent 57Fe Mossbauer spectroscopy on the hedenbergite - aegirine (Ca,Na)(Fe2+,Fe3+)Si2O6 solid solution Sample: Ae251, T = 298 K ; _database_code_amcsd 0004200 _chemical_compound_source 'Synthetic' _chemical_formula_sum '(Ca.742 Na.258) Fe Si2 O6' _cell_length_a 9.7938 _cell_length_b 8.9685 _cell_length_c 5.2632 _cell_angle_alpha 90 _cell_angle_beta 105.520 _cell_angle_gamma 90 _cell_volume 445.440 _exptl_crystal_density_diffrn 3.634 _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_occupancy _atom_site_U_iso_or_equiv Ca2 0.00000 0.30130 0.25000 0.74200 0.00930 Na2 0.00000 0.30130 0.25000 0.25800 0.00930 Fe2+1 0.00000 0.90490 0.25000 0.74200 0.00540 Fe3+1 0.00000 0.90490 0.25000 0.25800 0.00540 Si 0.28810 0.09180 0.23280 1.00000 0.00310 O1 0.11740 0.08650 0.14760 1.00000 0.00780 O2 0.36080 0.24960 0.31770 1.00000 0.00900 O3 0.35050 0.01650 0.99870 1.00000 0.00780