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 = 0.047 GPa ; _database_code_amcsd 0005004 _chemical_compound_source 'Parana, Brazil' _chemical_formula_sum 'Fe1.008 Mg.871 Ca.121 (Si1.98 Al.02) O6' _cell_length_a 9.722 _cell_length_b 8.941 _cell_length_c 5.247 _cell_angle_alpha 90 _cell_angle_beta 108.5 _cell_angle_gamma 90 _cell_volume 432.523 _exptl_crystal_density_diffrn 3.601 _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 0.25140 0.65490 0.23310 0.25300 0.01130 MgA 0.25140 0.65490 0.23310 0.74700 0.01130 FeB 0.25640 0.01880 0.23000 0.75500 0.01420 MgB 0.25640 0.01880 0.23000 0.12400 0.01420 CaB 0.25200 0.02700 0.28300 0.12100 0.03000 SiA 0.04320 0.34010 0.27480 0.99000 0.01000 AlA 0.04320 0.34010 0.27480 0.01000 0.01000 SiB 0.54770 0.83770 0.23850 0.99000 0.00830 AlB 0.54770 0.83770 0.23850 0.01000 0.00830 O1A 0.86900 0.33780 0.17000 1.00000 0.01200 O1B 0.37100 0.83790 0.13300 1.00000 0.00900 O2A 0.12300 0.49870 0.33300 1.00000 0.01100 O2B 0.62800 0.98680 0.36700 1.00000 0.02000 O3A 0.10400 0.26210 0.57400 1.00000 0.02000 O3B 0.60600 0.71280 0.48400 1.00000 0.01800