data_global _chemical_name_mineral 'Pigeonite' loop_ _publ_author_name 'Domeneghetti M C' 'Zema M' 'Tazzoli V' _journal_name_full 'American Mineralogist' _journal_volume 90 _journal_year 2005 _journal_page_first 1816 _journal_page_last 1823 _publ_section_title ; Kinetics of Fe2+-Mg order-disorder in P2_1/c pigeonite Sample: N.13, annealed at T = 650 C for t = 3120 min ; _database_code_amcsd 0003985 _chemical_compound_source 'Parana, Brazil' _chemical_formula_sum 'Mg.919 Fe.848 Ca.191 Mn.029 Na.003 Ti.01 Si1.984 Al.016 O6' _cell_length_a 9.7096 _cell_length_b 8.9413 _cell_length_c 5.2470 _cell_angle_alpha 90 _cell_angle_beta 108.499 _cell_angle_gamma 90 _cell_volume 431.989 _exptl_crystal_density_diffrn 3.561 _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 MgM2A 0.25533 0.01689 0.22781 0.16590 ? FeM2A 0.25533 0.01689 0.22781 0.61450 ? CaM2A 0.25533 0.01689 0.22781 0.07980 ? MnM2A 0.25533 0.01689 0.22781 0.02560 ? NaM2A 0.25533 0.01689 0.22781 0.00300 ? CaM2B 0.25447 0.04922 0.24971 0.11110 0.01248 MgM1 0.25045 0.65461 0.23156 0.75340 ? Fe2+M1 0.25045 0.65461 0.23156 0.21860 ? Fe3+M1 0.25045 0.65461 0.23156 0.01480 ? TiM1 0.25045 0.65461 0.23156 0.01010 ? MnM1 0.25045 0.65461 0.23156 0.00310 ? SiA 0.04272 0.34049 0.27670 1.00000 ? SiB 0.54947 0.83739 0.23849 0.98400 ? AlB 0.54947 0.83739 0.23849 0.01600 ? O1A 0.86763 0.33822 0.16891 1.00000 ? O2A 0.12176 0.49932 0.33229 1.00000 ? O3A 0.10416 0.26165 0.57769 1.00000 ? O1B 0.37362 0.83679 0.13453 1.00000 ? O2B 0.62899 0.98746 0.37304 1.00000 ? O3B 0.60495 0.70898 0.48085 1.00000 ? loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 MgM2A 0.01016 0.01151 0.00719 0.00046 0.00069 0.00176 FeM2A 0.01016 0.01151 0.00719 0.00046 0.00069 0.00176 CaM2A 0.01016 0.01151 0.00719 0.00046 0.00069 0.00176 MnM2A 0.01016 0.01151 0.00719 0.00046 0.00069 0.00176 NaM2A 0.01016 0.01151 0.00719 0.00046 0.00069 0.00176 MgM1 0.00818 0.00701 0.00788 0.00011 0.00262 0.00037 Fe2+M1 0.00818 0.00701 0.00788 0.00011 0.00262 0.00037 Fe3+M1 0.00818 0.00701 0.00788 0.00011 0.00262 0.00037 TiM1 0.00818 0.00701 0.00788 0.00011 0.00262 0.00037 MnM1 0.00818 0.00701 0.00788 0.00011 0.00262 0.00037 SiA 0.00632 0.00649 0.01001 -0.00061 0.00365 -0.00066 SiB 0.00655 0.00634 0.00786 -0.00107 0.00281 -0.00085 AlB 0.00655 0.00634 0.00786 -0.00107 0.00281 -0.00085 O1A 0.00727 0.00918 0.00976 0.00025 0.00309 -0.00014 O2A 0.01276 0.00826 0.01378 -0.00348 0.00619 -0.00154 O3A 0.00900 0.02304 0.02050 0.00073 0.00415 0.01422 O1B 0.00704 0.01006 0.00990 0.00054 0.00313 -0.00004 O2B 0.01409 0.01145 0.02132 -0.00584 0.00988 -0.00721 O3B 0.00838 0.01980 0.01339 0.00067 0.00361 0.00748