data_global _chemical_name_mineral 'Bementite' loop_ _publ_author_name 'Heinrich A R' 'Eggleton R A' 'Guggenheim S' _journal_name_full 'American Mineralogist' _journal_volume 79 _journal_year 1994 _journal_page_first 91 _journal_page_last 106 _publ_section_title ; Structure and polytypism of bementite, a modulated layer silicate ; _database_code_amcsd 0001635 _chemical_formula_sum 'Si6 Mn6.682 O23' _cell_length_a 14.838 _cell_length_b 17.584 _cell_length_c 14.700 _cell_angle_alpha 90 _cell_angle_beta 95.54 _cell_angle_gamma 90 _cell_volume 3817.483 _exptl_crystal_density_diffrn 3.144 _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 Si1 0.92100 0.46700 0.19900 1.00000 0.00760 Si2 0.71900 0.45100 0.20800 1.00000 0.00760 Si3 0.55600 0.56400 0.18400 1.00000 0.00760 Si4 0.99000 0.62600 0.17000 1.00000 0.00760 Si5 0.84500 0.74400 0.14900 1.00000 0.00760 Si6 0.64000 0.73000 0.16400 1.00000 0.00760 Si7 0.49400 0.84300 0.16000 1.00000 0.00760 Si8 0.56800 0.99900 0.18900 1.00000 0.00760 Si9 0.76800 0.01700 0.20400 1.00000 0.00760 Si10 0.29900 0.80700 0.17300 1.00000 0.00760 Si11 0.18400 0.66300 0.17700 1.00000 0.00760 Si12 0.93000 0.90600 0.17600 1.00000 0.00760 Mn1 0.00000 0.00000 0.00000 0.95000 0.01013 Mn2 0.22400 0.02500 -0.00800 0.79000 0.01013 Mn3 0.43400 0.06900 0.02300 0.96000 0.01013 Mn4 0.64300 0.12300 0.02200 0.96000 0.01013 Mn5 0.85400 0.13900 0.02800 0.98000 0.01013 Mn6 0.08100 0.17600 0.04500 0.85000 0.01013 Mn7 0.28400 0.22500 0.07200 1.00000 0.01013 Mn8 0.49300 0.25500 0.03500 0.88000 0.01013 Mn9 0.72300 0.29300 0.03800 1.00000 0.01013 Mn10 0.94100 0.31600 0.04200 1.00000 0.01013 Mn11 0.13900 0.35500 0.04100 1.00000 0.01013 Mn12 0.35900 0.39700 0.00200 0.99000 0.01013 Mn13 0.58000 0.42900 0.02100 1.00000 0.01013 Mn14 0.79700 0.45000 0.00100 1.00000 0.01013 Mn15 0.00000 0.00000 0.50000 0.96000 0.01013 O1 0.82000 0.49000 0.21000 1.00000 0.01520 O2 0.99000 0.54000 0.21000 1.00000 0.01520 O3 0.96000 0.41000 0.28000 1.00000 0.01520 O4 0.64000 0.51000 0.23000 1.00000 0.01520 O5 0.46000 0.56000 0.23000 1.00000 0.01520 O6 0.59000 0.65000 0.20000 1.00000 0.01520 O7 0.75000 0.74000 0.19000 1.00000 0.01520 O8 0.90000 0.67000 0.20000 1.00000 0.01520 O9 0.90000 0.82000 0.19000 1.00000 0.01520 O10 0.86000 0.96000 0.22000 1.00000 0.01520 O11 0.67000 0.97000 0.22000 1.00000 0.01520 O12 0.49000 0.93000 0.19000 1.00000 0.01520 O13 0.58000 0.80000 0.20000 1.00000 0.01520 O14 0.41000 0.80000 0.19000 1.00000 0.01520 O15 0.24000 0.74000 0.21000 1.00000 0.01520 O16 0.08000 0.67000 0.21000 1.00000 0.01520 O17 0.77000 0.09000 0.28000 1.00000 0.01520 O18 0.73000 0.39000 0.29000 1.00000 0.01520 O19 0.92000 0.92000 0.07000 1.00000 0.01520 O20 0.69000 0.88000 0.00000 1.00000 0.01520 O21 0.49000 0.85000 0.05000 1.00000 0.01520 O22 0.28000 0.81000 0.06000 1.00000 0.01520 O23 0.05000 0.79000 0.01000 1.00000 0.01520 O24 0.83000 0.75000 0.04000 1.00000 0.01520 O25 0.63000 0.73000 0.05000 1.00000 0.01520 O26 0.41000 0.68000 0.03000 1.00000 0.01520 O27 0.18000 0.65000 0.07000 1.00000 0.01520 O28 0.98000 0.62000 0.06000 1.00000 0.01520 O29 0.77000 0.57000 0.04000 1.00000 0.01520 O30 0.54000 0.54000 0.08000 1.00000 0.01520 O31 0.33000 0.51000 0.07000 1.00000 0.01520 O32 0.12000 0.47000 0.08000 1.00000 0.01520 O33 0.92000 0.43000 0.09000 1.00000 0.01520 O34 0.70000 0.41000 0.11000 1.00000 0.01520 O35 0.48000 0.37000 0.08000 1.00000 0.01520 O36 0.28000 0.34000 0.11000 1.00000 0.01520 O37 0.06000 0.29000 0.13000 1.00000 0.01520 O38 0.84000 0.24000 0.08000 1.00000 0.01520 O39 0.63000 0.22000 0.10000 1.00000 0.01520 O40 0.41000 0.17000 0.09000 1.00000 0.01520 O41 0.21000 0.12000 0.10000 1.00000 0.01520 O42 0.98000 0.10000 0.07000 1.00000 0.01520 O43 0.76000 0.06000 0.10000 1.00000 0.01520 O44 0.56000 0.03000 0.09000 1.00000 0.01520 O45 0.35000 0.98000 0.07000 1.00000 0.01520 O46 0.13000 0.96000 0.06000 1.00000 0.01520