data_global _chemical_name_mineral 'Aegirine' loop_ _publ_author_name 'McCarthy A C' 'Downs R T' 'Thompson R M' 'Redhammer G J' _journal_name_full 'American Mineralogist' _journal_volume 93 _journal_year 2008 _journal_page_first 1829 _journal_page_last 1837 _publ_section_title ; In situ high-pressure single-crystal X-ray study of aegirine, NaFe3+Si2O6, and the role of M1 size in clinopyroxene compressibility Note: Pressure = 7.3 GPa ; _database_code_amcsd 0004763 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Na Fe Si2 O6' _cell_length_a 9.4711 _cell_length_b 8.6068 _cell_length_c 5.1915 _cell_angle_alpha 90 _cell_angle_beta 106.633 _cell_angle_gamma 90 _cell_volume 405.482 _exptl_crystal_density_diffrn 3.784 _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 Na 0.00000 0.30440 0.25000 0.01381 Fe 0.00000 0.90140 0.25000 0.00811 Si 0.29110 0.09170 0.23650 0.00747 O1 0.11460 0.08210 0.14160 0.00811 O2 0.35740 0.26070 0.31350 0.01051 O3 0.35490 0.01560 0.00580 0.00988