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.35, annealed at T = 700 C for t = 600 min ; _database_code_amcsd 0003970 _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 9.7132 _cell_length_b 8.9469 _cell_length_c 5.2500 _cell_angle_alpha 90 _cell_angle_beta 108.484 _cell_angle_gamma 90 _cell_volume 432.704 _exptl_crystal_density_diffrn 3.556 _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 0.25525 0.01663 0.22767 0.17500 ? FeM2A 0.25525 0.01663 0.22767 0.60510 ? CaM2A 0.25525 0.01663 0.22767 0.05990 ? MnM2A 0.25525 0.01663 0.22767 0.02550 ? NaM2A 0.25525 0.01663 0.22767 0.00300 ? CaM2B 0.25429 0.04810 0.25041 0.13140 0.01270 MgM1 0.25043 0.65458 0.23173 0.74350 ? Fe2+M1 0.25043 0.65458 0.23173 0.22830 ? Fe3+M1 0.25043 0.65458 0.23173 0.01480 ? TiM1 0.25043 0.65458 0.23173 0.01010 ? MnM1 0.25043 0.65458 0.23173 0.00330 ? SiA 0.04276 0.34055 0.27654 1.00000 ? SiB 0.54941 0.83740 0.23861 0.98400 ? AlB 0.54941 0.83740 0.23861 0.01600 ? O1A 0.86775 0.33830 0.16891 1.00000 ? O2A 0.12157 0.49940 0.33197 1.00000 ? O3A 0.10425 0.26129 0.57686 1.00000 ? O1B 0.37381 0.83674 0.13500 1.00000 ? O2B 0.62868 0.98753 0.37275 1.00000 ? O3B 0.60471 0.70902 0.48120 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 0.00979 0.01091 0.00672 0.00038 0.00063 0.00197 FeM2A 0.00979 0.01091 0.00672 0.00038 0.00063 0.00197 CaM2A 0.00979 0.01091 0.00672 0.00038 0.00063 0.00197 MnM2A 0.00979 0.01091 0.00672 0.00038 0.00063 0.00197 NaM2A 0.00979 0.01091 0.00672 0.00038 0.00063 0.00197 MgM1 0.00759 0.00670 0.00756 0.00004 0.00250 0.00030 Fe2+M1 0.00759 0.00670 0.00756 0.00004 0.00250 0.00030 Fe3+M1 0.00759 0.00670 0.00756 0.00004 0.00250 0.00030 TiM1 0.00759 0.00670 0.00756 0.00004 0.00250 0.00030 MnM1 0.00759 0.00670 0.00756 0.00004 0.00250 0.00030 SiA 0.00586 0.00627 0.01006 -0.00057 0.00326 -0.00072 SiB 0.00616 0.00628 0.00772 -0.00111 0.00256 -0.00098 AlB 0.00616 0.00628 0.00772 -0.00111 0.00256 -0.00098 O1A 0.00614 0.00950 0.00986 0.00013 0.00248 -0.00019 O2A 0.01247 0.00845 0.01355 -0.00328 0.00604 -0.00139 O3A 0.00774 0.02272 0.02122 0.00051 0.00402 0.01373 O1B 0.00692 0.00937 0.01009 0.00035 0.00289 0.00006 O2B 0.01422 0.01126 0.02145 -0.00574 0.00983 -0.00760 O3B 0.00753 0.01938 0.01324 0.00066 0.00324 0.00755