data_global _chemical_name_mineral 'Serandite' loop_ _publ_author_name 'Williams E R' 'Weller M T' _journal_name_full 'American Mineralogist' _journal_volume 99 _journal_year 2014 _journal_page_first 1755 _journal_page_last 1760 _publ_section_title ; A variable-temperature neutron diffraction study of serandite: A Mn-silicate framework with a very strong, two-proton site, hydrogen bond Note: T = 4 K ; _database_code_amcsd 0020402 _chemical_compound_source 'Mont St. Hilaire, Quebec, Canada' _chemical_formula_sum 'Mn1.944 Ca.056 Na Si3 O9 H' _cell_length_a 7.6844 _cell_length_b 6.8913 _cell_length_c 6.73493 _cell_angle_alpha 90.4576 _cell_angle_beta 94.0805 _cell_angle_gamma 102.7770 _cell_volume 346.835 _exptl_crystal_density_diffrn 3.460 _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 _atom_site_U_iso_or_equiv Mn1 0.85330 0.58960 0.13940 1.00000 0.00250 Mn2 0.85110 0.08630 0.13100 0.94400 0.01050 Ca2 0.85110 0.08630 0.13100 0.05600 0.01050 Na1 0.55980 0.25140 0.35820 1.00000 0.01000 Si1 0.21520 0.41060 0.34570 1.00000 0.00020 Si2 0.20680 0.94420 0.34610 1.00000 0.00020 Si3 0.45360 0.73850 0.14420 1.00000 0.00020 O1 0.66570 0.79560 0.10890 1.00000 0.00450 O2 0.32040 0.70610 0.93950 1.00000 0.00450 O3 0.17840 0.49700 0.55550 1.00000 0.00450 O4 0.15960 0.84190 0.55930 1.00000 0.00450 O5 0.06280 0.39420 0.16670 1.00000 0.00450 O6 0.05310 0.89220 0.17270 1.00000 0.00450 O7 0.40820 0.53440 0.27570 1.00000 0.00450 O8 0.39780 0.91020 0.28710 1.00000 0.00450 O9 0.25820 0.18860 0.39260 1.00000 0.00450 H16 0.14860 0.63500 0.55440 0.78000 0.01970 H17 0.14100 0.71200 0.49800 0.22000 0.01970