data_global _chemical_name_mineral 'Pigeonite' loop_ _publ_author_name 'Alvaro M' 'Nestola F' 'Ballaran T B' 'Camara F' 'Domeneghetti M C' 'Tazzoli V' _journal_name_full 'American Mineralogist' _journal_volume 95 _journal_year 2010 _journal_page_first 300 _journal_page_last 311 _publ_section_title ; High-pressure phase transition of a natural pigeonite Note: P = 1.794 GPa ; _database_code_amcsd 0005006 _chemical_compound_source 'Parana, Brazil' _chemical_formula_sum 'Fe1.008 Mg.871 Ca.121 (Si1.98 Al.02) O6' _cell_length_a 9.659 _cell_length_b 8.877 _cell_length_c 5.218 _cell_angle_alpha 90 _cell_angle_beta 108.09 _cell_angle_gamma 90 _cell_volume 425.291 _exptl_crystal_density_diffrn 3.662 _symmetry_space_group_name_H-M 'P 1 21/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,1/2+z' '-x,1/2+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 _atom_site_U_iso_or_equiv FeA 0.25130 0.65590 0.23050 0.25300 0.01080 MgA 0.25130 0.65590 0.23050 0.74700 0.01080 FeB 0.25640 0.02050 0.22720 0.75500 0.01340 MgB 0.25640 0.02050 0.22720 0.12400 0.01340 CaB 0.25000 0.03300 0.27900 0.12100 0.03000 SiA 0.04260 0.34160 0.27360 0.99000 0.00970 AlA 0.04260 0.34160 0.27360 0.01000 0.00970 SiB 0.54920 0.83820 0.23600 0.99000 0.00850 AlB 0.54920 0.83820 0.23600 0.01000 0.00850 O1A 0.86800 0.33800 0.16900 1.00000 0.00900 O1B 0.37300 0.83850 0.13300 1.00000 0.01000 O2A 0.12300 0.50020 0.33300 1.00000 0.01300 O2B 0.62700 0.98940 0.37000 1.00000 0.01500 O3A 0.10200 0.26000 0.57200 1.00000 0.02400 O3B 0.60500 0.70900 0.47500 1.00000 0.02000