data_global _chemical_name_mineral 'Serandite' loop_ _publ_author_name 'Jacobsen S D' 'Smyth J R' 'Swope R J' 'Sheldon R I' _journal_name_full 'American Mineralogist' _journal_volume 85 _journal_year 2000 _journal_page_first 745 _journal_page_last 752 _publ_section_title ; Two proton positions in the very strong hydrogen bond of serandite, NaMn2[Si3O8(OH)] Sample: neutron ; _database_code_amcsd 0002431 _chemical_formula_sum 'Na Mn1.924 Si3 H O9' _cell_length_a 7.7163 _cell_length_b 6.9116 _cell_length_c 6.7368 _cell_angle_alpha 90.465 _cell_angle_beta 94.037 _cell_angle_gamma 102.844 _cell_volume 349.324 _exptl_crystal_density_diffrn 3.403 _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 Na 0.55570 0.25530 0.35290 1.00000 ? Mn1 0.85310 0.59450 0.13490 0.94100 ? Mn2 0.84910 0.08400 0.13290 0.98300 ? Si1 0.21510 0.40170 0.34240 1.00000 ? Si2 0.20590 0.95110 0.35120 1.00000 ? Si3 0.45430 0.73700 0.14280 1.00000 ? H1 0.14820 0.63740 0.54980 0.84200 ? H2 0.15180 0.68720 0.54830 0.15800 0.01500 O1 0.66430 0.79430 0.11380 1.00000 ? O2 0.32260 0.70650 0.94350 1.00000 ? O3 0.17880 0.49260 0.55540 1.00000 ? O4 0.15980 0.84430 0.55720 1.00000 ? O5 0.06140 0.39120 0.16710 1.00000 ? O6 0.05190 0.89120 0.17240 1.00000 ? O7 0.40710 0.53350 0.27720 1.00000 ? O8 0.39720 0.90670 0.28660 1.00000 ? O9 0.25930 0.18880 0.39310 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 Na 0.00800 0.01490 0.01950 0.00000 0.00280 0.00050 Mn1 0.00760 0.00700 0.00910 0.00030 0.00070 0.00020 Mn2 0.00700 0.00690 0.00870 0.00210 0.00110 -0.00020 Si1 0.00460 0.00420 0.00730 0.00120 0.00070 -0.00010 Si2 0.00540 0.00420 0.00530 0.00120 0.00040 0.00050 Si3 0.00400 0.00410 0.00690 0.00100 0.00020 -0.00050 H1 0.02040 0.02170 0.02110 0.00700 0.00370 0.00090 O1 0.00490 0.00750 0.01360 0.00080 0.00300 0.00008 O2 0.00750 0.00870 0.00920 0.00160 -0.00150 -0.00070 O3 0.01050 0.00720 0.00840 0.00350 0.00100 -0.00140 O4 0.01320 0.00560 0.00750 0.00140 0.00240 0.00150 O5 0.00630 0.00990 0.00710 0.00130 -0.00010 0.00100 O6 0.00650 0.00770 0.00890 0.00120 -0.00110 -0.00070 O7 0.00560 0.00720 0.01450 0.00010 0.00050 0.00420 O8 0.00640 0.00830 0.01330 0.00300 0.00050 -0.00410 O9 0.00920 0.00320 0.01380 0.00180 0.00050 -0.00010