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 = 240 min ; _database_code_amcsd 0003981 _chemical_compound_source 'Parana, Brazil' _chemical_formula_sum 'Mg.918 Fe.849 Ca.191 Mn.029 Na.003 Ti.01 Si1.984 Al.016 O6' _cell_length_a 9.7086 _cell_length_b 8.9421 _cell_length_c 5.2473 _cell_angle_alpha 90 _cell_angle_beta 108.503 _cell_angle_gamma 90 _cell_volume 431.997 _exptl_crystal_density_diffrn 3.562 _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 0.25530 0.01689 0.22790 0.15370 ? FeM2A 0.25530 0.01689 0.22790 0.62670 ? CaM2A 0.25530 0.01689 0.22790 0.07740 ? MnM2A 0.25530 0.01689 0.22790 0.02580 ? NaM2A 0.25530 0.01689 0.22790 0.00300 ? CaM2B 0.25425 0.05020 0.25025 0.11330 0.01170 MgM1 0.25046 0.65463 0.23161 0.76470 ? Fe2+M1 0.25046 0.65463 0.23161 0.20740 ? Fe3+M1 0.25046 0.65463 0.23161 0.01480 ? TiM1 0.25046 0.65463 0.23161 0.01010 ? MnM1 0.25046 0.65463 0.23161 0.00290 ? SiA 0.04272 0.34054 0.27665 1.00000 ? SiB 0.54943 0.83746 0.23844 0.98400 ? AlB 0.54943 0.83746 0.23844 0.01600 ? O1A 0.86755 0.33812 0.16867 1.00000 ? O2A 0.12164 0.49937 0.33195 1.00000 ? O3A 0.10408 0.26163 0.57760 1.00000 ? O1B 0.37362 0.83660 0.13463 1.00000 ? O2B 0.62899 0.98747 0.37285 1.00000 ? O3B 0.60487 0.70902 0.48072 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 0.00972 0.01136 0.00692 0.00038 0.00072 0.00174 FeM2A 0.00972 0.01136 0.00692 0.00038 0.00072 0.00174 CaM2A 0.00972 0.01136 0.00692 0.00038 0.00072 0.00174 MnM2A 0.00972 0.01136 0.00692 0.00038 0.00072 0.00174 NaM2A 0.00972 0.01136 0.00692 0.00038 0.00072 0.00174 MgM1 0.00768 0.00719 0.00784 0.00010 0.00262 0.00033 Fe2+M1 0.00768 0.00719 0.00784 0.00010 0.00262 0.00033 Fe3+M1 0.00768 0.00719 0.00784 0.00010 0.00262 0.00033 TiM1 0.00768 0.00719 0.00784 0.00010 0.00262 0.00033 MnM1 0.00768 0.00719 0.00784 0.00010 0.00262 0.00033 SiA 0.00584 0.00663 0.00977 -0.00051 0.00341 -0.00065 SiB 0.00617 0.00656 0.00776 -0.00099 0.00281 -0.00088 AlB 0.00617 0.00656 0.00776 -0.00099 0.00281 -0.00088 O1A 0.00652 0.00971 0.00969 0.00032 0.00282 -0.00024 O2A 0.01215 0.00885 0.01353 -0.00317 0.00626 -0.00141 O3A 0.00871 0.02294 0.02006 0.00070 0.00424 0.01373 O1B 0.00666 0.01031 0.00973 0.00046 0.00313 -0.00013 O2B 0.01398 0.01177 0.02125 -0.00593 0.00984 -0.00715 O3B 0.00749 0.02053 0.01312 0.00066 0.00315 0.00783