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 = 5.47 GPa ; _database_code_amcsd 0004762 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Na Fe Si2 O6' _cell_length_a 9.5148 _cell_length_b 8.6568 _cell_length_c 5.2188 _cell_angle_alpha 90 _cell_angle_beta 106.844 _cell_angle_gamma 90 _cell_volume 411.418 _exptl_crystal_density_diffrn 3.729 _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 0.30290 0.25000 0.01406 Fe 0.00000 0.90060 0.25000 0.00735 Si 0.29090 0.09090 0.23660 0.00684 O1 0.11410 0.08010 0.14140 0.00849 O2 0.35730 0.26020 0.30810 0.00975 O3 0.35480 0.01300 0.00940 0.00912