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 = 1000 min ; _database_code_amcsd 0003971 _chemical_compound_source 'Parana, Brazil' _chemical_formula_sum 'Mg.917 Fe.85 Ca.191 Mn.029 Na.003 Ti.01 Si1.984 Al.016 O6' _cell_length_a 9.7096 _cell_length_b 8.9421 _cell_length_c 5.2464 _cell_angle_alpha 90 _cell_angle_beta 108.476 _cell_angle_gamma 90 _cell_volume 432.036 _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 0.25525 0.01654 0.22771 0.17690 ? FeM2A 0.25525 0.01654 0.22771 0.60350 ? CaM2A 0.25525 0.01654 0.22771 0.06160 ? MnM2A 0.25525 0.01654 0.22771 0.02560 ? NaM2A 0.25525 0.01654 0.22771 0.00300 ? CaM2B 0.25428 0.04830 0.24847 0.12940 0.01122 MgM1 0.25041 0.65460 0.23175 0.74020 ? Fe2+M1 0.25041 0.65460 0.23175 0.23140 ? Fe3+M1 0.25041 0.65460 0.23175 0.01500 ? TiM1 0.25041 0.65460 0.23175 0.01000 ? MnM1 0.25041 0.65460 0.23175 0.00340 ? SiA 0.04280 0.34055 0.27651 1.00000 ? SiB 0.54942 0.83741 0.23858 0.98400 ? AlB 0.54942 0.83741 0.23858 0.01600 ? O1A 0.86765 0.33830 0.16885 1.00000 ? O2A 0.12160 0.49962 0.33206 1.00000 ? O3A 0.10417 0.26143 0.57672 1.00000 ? O1B 0.37364 0.83671 0.13496 1.00000 ? O2B 0.62875 0.98765 0.37278 1.00000 ? O3B 0.60470 0.70906 0.48102 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 0.00988 0.01086 0.00673 0.00039 0.00066 0.00183 FeM2A 0.00988 0.01086 0.00673 0.00039 0.00066 0.00183 CaM2A 0.00988 0.01086 0.00673 0.00039 0.00066 0.00183 MnM2A 0.00988 0.01086 0.00673 0.00039 0.00066 0.00183 NaM2A 0.00988 0.01086 0.00673 0.00039 0.00066 0.00183 MgM1 0.00775 0.00686 0.00758 0.00009 0.00248 0.00031 Fe2+M1 0.00775 0.00686 0.00758 0.00009 0.00248 0.00031 Fe3+M1 0.00775 0.00686 0.00758 0.00009 0.00248 0.00031 TiM1 0.00775 0.00686 0.00758 0.00009 0.00248 0.00031 MnM1 0.00775 0.00686 0.00758 0.00009 0.00248 0.00031 SiA 0.00573 0.00648 0.00995 -0.00055 0.00333 -0.00062 SiB 0.00618 0.00632 0.00758 -0.00113 0.00268 -0.00097 AlB 0.00618 0.00632 0.00758 -0.00113 0.00268 -0.00097 O1A 0.00603 0.00938 0.00944 0.00033 0.00246 0.00006 O2A 0.01263 0.00838 0.01307 -0.00316 0.00616 -0.00132 O3A 0.00864 0.02331 0.02083 0.00054 0.00421 0.01424 O1B 0.00674 0.00975 0.00993 0.00055 0.00303 -0.00011 O2B 0.01438 0.01153 0.02146 -0.00604 0.01029 -0.00773 O3B 0.00773 0.01972 0.01324 0.00058 0.00366 0.00770