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 = 0.984 GPa ; _database_code_amcsd 0005005 _chemical_compound_source 'Parana, Brazil' _chemical_formula_sum 'Fe1.008 Mg.871 Ca.121 (Si1.98 Al.02) O6' _cell_length_a 9.701 _cell_length_b 8.887 _cell_length_c 5.226 _cell_angle_alpha 90 _cell_angle_beta 108.38 _cell_angle_gamma 90 _cell_volume 427.564 _exptl_crystal_density_diffrn 3.642 _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 0.25200 0.65600 0.23280 0.25300 0.01150 MgA 0.25200 0.65600 0.23280 0.74700 0.01150 FeB 0.25590 0.02060 0.22800 0.75500 0.01400 MgB 0.25590 0.02060 0.22800 0.12400 0.01400 CaB 0.24800 0.01600 0.28100 0.12100 0.03000 SiA 0.04280 0.34110 0.27470 0.99000 0.01060 AlA 0.04280 0.34110 0.27470 0.01000 0.01060 SiB 0.54890 0.83700 0.23750 0.99000 0.00880 AlB 0.54890 0.83700 0.23750 0.01000 0.00880 O1A 0.87000 0.34090 0.17000 1.00000 0.01000 O1B 0.37200 0.83750 0.13200 1.00000 0.01000 O2A 0.12300 0.49990 0.33300 1.00000 0.00900 O2B 0.62700 0.98900 0.36800 1.00000 0.01900 O3A 0.10500 0.26000 0.57600 1.00000 0.02100 O3B 0.60600 0.71100 0.47800 1.00000 0.01700