data_global _chemical_name_mineral 'Aenigmatite' loop_ _publ_author_name 'Gasparik T' 'Parise J B' 'Reeder R J' 'Young V G' 'Wilford W S' _journal_name_full 'American Mineralogist' _journal_volume 84 _journal_year 1999 _journal_page_first 257 _journal_page_last 266 _publ_section_title ; Composition, stability, and structure of a new member of the aenigmatite group, Na2Mg4+xFe2-2xSi6+xO20, synthesized at 13-14 GPa ; _database_code_amcsd 0002100 _chemical_formula_sum 'Mg2.163 Si3.188 Fe.65 Na O10' _cell_length_a 10.328 _cell_length_b 10.724 _cell_length_c 8.805 _cell_angle_alpha 105.15 _cell_angle_beta 96.85 _cell_angle_gamma 125.47 _cell_volume 719.667 _exptl_crystal_density_diffrn 3.335 _symmetry_space_group_name_H-M 'P -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Mg1 0.00000 0.00000 0.50000 0.68900 Si1 0.00000 0.00000 0.50000 0.06000 Fe1 0.00000 0.00000 0.50000 0.25100 Mg2 0.00000 0.50000 0.00000 0.64600 Si2 0.00000 0.50000 0.00000 0.05600 Fe2 0.00000 0.50000 0.00000 0.29800 Mg3 0.31390 0.84890 0.17800 0.69900 Si3 0.31390 0.84890 0.17800 0.06100 Fe3 0.31390 0.84890 0.17800 0.24000 Mg4 0.76870 0.81910 0.15080 0.72400 Si4 0.76870 0.81910 0.15080 0.06300 Fe4 0.76870 0.81910 0.15080 0.21300 Mg5 0.09490 0.93940 0.05590 0.76500 Si5 0.09490 0.93940 0.05590 0.06600 Fe5 0.09490 0.93940 0.05590 0.16900 Mg6 0.59590 0.94220 0.06460 0.72800 Si6 0.59590 0.94220 0.06460 0.06300 Fe6 0.59590 0.94220 0.06460 0.20900 Mg7 0.99200 0.73500 0.26490 0.74200 Si7 0.99200 0.73500 0.26490 0.06400 Fe7 0.99200 0.73500 0.26490 0.19400 Si1 0.47670 0.23280 0.33200 1.00000 Si2 0.98360 0.23390 0.34510 1.00000 Si3 0.79100 0.34280 0.24020 1.00000 Si4 0.27930 0.33990 0.22540 1.00000 Si5 0.64970 0.94930 0.44360 1.00000 Si6 0.35490 0.56020 0.04580 1.00000 Na1 0.20930 0.63440 0.39110 1.00000 Na2 0.66210 0.61180 0.36980 1.00000 O1 0.35550 0.06500 0.16280 1.00000 O2 0.86000 0.06590 0.17430 1.00000 O3 0.55950 0.96050 0.29150 1.00000 O4 0.02550 0.93570 0.26930 1.00000 O5 0.23140 0.87180 0.39020 1.00000 O6 0.74860 0.88270 0.39010 1.00000 O7 0.49260 0.19550 0.49840 1.00000 O8 0.95560 0.77740 0.48300 1.00000 O9 0.89700 0.32180 0.37010 1.00000 O10 0.40290 0.33630 0.35330 1.00000 O11 0.65880 0.17290 0.06940 1.00000 O12 0.15380 0.16750 0.06170 1.00000 O13 0.52890 0.71040 0.03530 1.00000 O14 0.06050 0.72880 0.06540 1.00000 O15 0.24260 0.61330 0.11250 1.00000 O16 0.75120 0.60990 0.12830 1.00000 O17 0.40340 0.50150 0.18890 1.00000 O18 0.93470 0.51120 0.22430 1.00000 O19 0.16640 0.36960 0.31950 1.00000 O20 0.67380 0.36660 0.33720 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 Mg1 0.01200 0.00900 0.01500 0.00800 -0.00300 -0.00100 Si1 0.01200 0.00900 0.01500 0.00800 -0.00300 -0.00100 Fe1 0.01200 0.00900 0.01500 0.00800 -0.00300 -0.00100 Mg2 0.01000 0.01300 0.01400 0.00500 0.00400 0.00000 Si2 0.01000 0.01300 0.01400 0.00500 0.00400 0.00000 Fe2 0.01000 0.01300 0.01400 0.00500 0.00400 0.00000 Mg3 0.01200 0.01100 0.01000 0.00800 0.00500 0.00500 Si3 0.01200 0.01100 0.01000 0.00800 0.00500 0.00500 Fe3 0.01200 0.01100 0.01000 0.00800 0.00500 0.00500 Mg4 0.00800 0.00800 0.00700 0.00500 0.00200 0.00200 Si4 0.00800 0.00800 0.00700 0.00500 0.00200 0.00200 Fe4 0.00800 0.00800 0.00700 0.00500 0.00200 0.00200 Mg5 0.00900 0.01500 0.01300 0.00700 0.00600 0.00700 Si5 0.00900 0.01500 0.01300 0.00700 0.00600 0.00700 Fe5 0.00900 0.01500 0.01300 0.00700 0.00600 0.00700 Mg6 0.00900 0.01100 0.00700 0.00600 0.00500 0.00500 Si6 0.00900 0.01100 0.00700 0.00600 0.00500 0.00500 Fe6 0.00900 0.01100 0.00700 0.00600 0.00500 0.00500 Mg7 0.00700 0.00700 0.00800 0.00500 0.00000 0.00000 Si7 0.00700 0.00700 0.00800 0.00500 0.00000 0.00000 Fe7 0.00700 0.00700 0.00800 0.00500 0.00000 0.00000 Si1 0.00800 0.01000 0.00400 0.00600 0.00300 0.00400 Si2 0.00900 0.01100 0.00800 0.00700 0.00400 0.00600 Si3 0.00700 0.01100 0.00300 0.00600 0.00300 0.00300 Si4 0.00700 0.00800 0.00400 0.00500 0.00300 0.00300 Si5 0.00800 0.00600 0.00800 0.00400 0.00300 0.00400 Si6 0.00800 0.00500 0.00700 0.00400 0.00200 0.00200 Na1 0.01300 0.01100 0.01400 0.00600 0.00100 0.00500 Na2 0.01100 0.01400 0.02000 0.00800 0.00600 0.01000 O1 0.00700 0.00900 0.01000 0.00500 0.00600 0.00700 O2 0.00700 0.01100 0.01600 0.00700 0.00400 0.00700 O3 0.00600 0.01200 0.00800 0.00500 0.00000 0.00400 O4 0.02400 0.03000 0.01000 0.02000 0.00000 0.00300 O5 0.01000 0.00400 0.00600 0.00600 0.00200 0.00100 O6 0.01000 0.00500 0.01100 0.00500 0.00300 0.00400 O7 0.00700 0.01300 0.00900 0.00600 0.00500 0.00500 O8 0.01100 0.01400 0.01700 0.00500 -0.00200 0.00900 O9 0.01300 0.01400 0.01200 0.01000 0.00400 0.00100 O10 0.00900 0.00900 0.00700 0.00600 0.00500 0.00300 O11 0.01100 0.00500 0.00500 0.00400 0.00100 -0.00200 O12 0.01100 0.00500 0.00600 0.00300 0.00000 -0.00200 O13 0.01300 0.00600 0.00700 0.00600 0.00400 0.00100 O14 0.00600 0.01100 0.02500 0.00700 0.00100 0.00400 O15 0.00800 0.01000 0.00700 0.00700 -0.00100 0.00000 O16 0.01300 0.00700 0.01400 0.00300 0.00400 -0.00200 O17 0.00800 0.00500 0.00900 0.00300 0.00400 0.00200 O18 0.00700 0.01800 0.01100 0.00700 0.00300 0.01000 O19 0.00700 0.00400 0.01300 0.00200 0.00500 0.00300 O20 0.00500 0.00700 0.00500 0.00200 0.00300 0.00000