data_global _chemical_name_mineral 'Trona' loop_ _publ_author_name 'Choi C S' 'Mighell A D' _journal_name_full 'Acta Crystallographica, Section B' _journal_volume 38 _journal_year 1982 _journal_page_first 2874 _journal_page_last 2876 _publ_section_title ; Neutron diffraction study of sodium sesquicarbonate dihydrate Note: H3 disordered model, this is the prefered model ; _database_code_amcsd 0009779 _chemical_formula_sum 'Na3 C2 O8 H5' _cell_length_a 20.36 _cell_length_b 3.48 _cell_length_c 10.29 _cell_angle_alpha 90 _cell_angle_beta 106.48 _cell_angle_gamma 90 _cell_volume 699.124 _exptl_crystal_density_diffrn 2.147 _symmetry_space_group_name_H-M 'C 1 2/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' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-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 Na1 0.00000 0.74786 0.25000 1.00000 ? Na2 0.15059 0.16359 0.42612 1.00000 ? C 0.09303 0.26524 0.10317 1.00000 ? O1 0.15103 0.39845 0.10200 1.00000 ? O2 0.05433 0.12980 0.98823 1.00000 ? O3 0.07258 0.25364 0.20797 1.00000 ? O4 0.21207 0.66563 0.35376 1.00000 ? H1 0.19149 0.59393 0.25966 1.00000 ? H2 0.25913 0.73060 0.36351 1.00000 ? H3 0.00480 0.01210 0.00060 0.50000 0.02584 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 Na1 0.01854 0.01276 0.01322 0.00000 0.00703 0.00000 Na2 0.02433 0.01724 0.01356 -0.00289 0.00586 -0.00247 C 0.01101 0.01086 0.00582 0.00100 0.00234 0.00056 O1 0.01487 0.02307 0.01174 -0.00203 0.00488 0.00237 O2 0.01583 0.02326 0.00671 -0.00286 0.00264 -0.00291 O3 0.01641 0.01547 0.00769 -0.00162 0.00595 -0.00104 O4 0.02201 0.02348 0.01470 -0.00737 0.00771 -0.00480 H1 0.03418 0.03515 0.02358 -0.00434 0.00732 -0.00160 H2 0.02819 0.03896 0.03127 -0.00520 0.00800 -0.00064