data_global _chemical_name_mineral 'Margarite-2M1' loop_ _publ_author_name 'Guggenheim S' 'Bailey S W' _journal_name_full 'American Mineralogist' _journal_volume 60 _journal_year 1975 _journal_page_first 1023 _journal_page_last 1029 _publ_section_title ; Refinement of the margarite structure in subgroup symmetry ; _database_code_amcsd 0000477 _chemical_formula_sum 'Ca Si2 Al4 H2 O12' _cell_length_a 5.1038 _cell_length_b 8.8287 _cell_length_c 19.148 _cell_angle_alpha 90 _cell_angle_beta 95.46 _cell_angle_gamma 90 _cell_volume 858.893 _exptl_crystal_density_diffrn 3.079 _symmetry_space_group_name_H-M 'C 1 c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+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 Ca 0.00000 0.09320 0.25000 1.00000 0.01292 Si1 0.46470 0.92850 0.14160 0.50000 0.01254 Si2 0.53640 0.07520 0.85490 0.50000 0.00735 Si3 0.45670 0.25720 0.14440 0.50000 0.00773 Si4 0.55000 0.74370 0.85730 0.50000 0.01229 Al1 0.46470 0.92850 0.14160 0.50000 0.01254 Al2 0.53640 0.07520 0.85490 0.50000 0.00735 Al3 0.45670 0.25720 0.14440 0.50000 0.00773 Al4 0.55000 0.74370 0.85730 0.50000 0.01229 Al5 0.74690 0.91870 0.99970 1.00000 0.00925 Al6 0.25100 0.08630 0.99980 1.00000 0.00697 H1 0.39700 0.63700 0.08300 1.00000 0.00988 H2 0.60300 0.36300 0.91700 1.00000 0.00988 O1 0.96000 0.44360 0.05120 1.00000 0.01267 O2 0.04600 0.55850 0.93900 1.00000 0.00633 O3 0.39500 0.25400 0.05680 1.00000 0.01140 O4 0.61900 0.74890 0.94470 1.00000 0.00887 O5 0.36700 0.09740 0.17750 1.00000 0.01393 O6 0.64100 0.91670 0.82260 1.00000 0.00760 O7 0.26600 0.77840 0.16650 1.00000 0.00633 O8 0.71100 0.21400 0.83040 1.00000 0.01393 O9 0.28700 0.39260 0.17850 1.00000 0.00507 O10 0.73700 0.60800 0.82110 1.00000 0.01773 O11 0.44800 0.56930 0.04880 1.00000 0.00507 O12 0.54300 0.44170 0.94680 1.00000 0.01267