data_global _chemical_name_mineral 'Sodium alum' loop_ _publ_author_name 'Cromer D T' 'Kay M I' 'Larson A C' _journal_name_full 'Acta Crystallographica' _journal_volume 22 _journal_year 1967 _journal_page_first 182 _journal_page_last 187 _publ_section_title ; Refinement of the alum structures. II. X-ray and neutron diffraction of NaAl(SO4)2*12H2O, gamma alum ; _database_code_amcsd 0009306 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Na Al S2 O20 H24' _cell_length_a 12.213 _cell_length_b 12.213 _cell_length_c 12.213 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1821.659 _exptl_crystal_density_diffrn 1.671 _symmetry_space_group_name_H-M 'P a 3' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+z,x,1/2-y' 'z,1/2-x,1/2+y' '1/2-z,1/2+x,y' '-z,-x,-y' '1/2+y,1/2-z,-x' '1/2-y,-z,1/2+x' '-y,1/2+z,1/2-x' 'y,z,x' 'x,1/2-y,1/2+z' '1/2-x,1/2+y,z' '1/2+x,y,1/2-z' '-x,-y,-z' '1/2-z,-x,1/2+y' '-z,1/2+x,1/2-y' '1/2+z,1/2-x,-y' 'z,x,y' '1/2-y,1/2+z,x' '1/2+y,z,1/2-x' 'y,1/2-z,1/2+x' '-y,-z,-x' '-x,1/2+y,1/2-z' '1/2+x,1/2-y,-z' '1/2-x,-y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Na 0.50000 0.50000 0.50000 ? Al 0.00000 0.00000 0.00000 ? S 0.26520 0.26520 0.26520 ? OSl 0.33430 0.33430 0.33430 ? OS2 0.29570 0.27830 0.15080 ? Ow3 0.07670 0.04030 0.31880 ? Ow4 0.13710 0.95960 0.05730 ? H1 0.58500 0.31900 0.37800 0.04306 H2 0.48600 0.30800 0.38300 0.05066 H3 0.55500 0.20200 0.50200 0.04053 H4 0.58800 0.33900 0.11300 0.03040 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 0.03113 0.03113 0.03113 -0.00227 -0.00227 -0.00227 Al 0.02146 0.02146 0.02146 0.00378 0.00378 0.00378 S 0.03000 0.03000 0.03000 0.00332 0.00332 0.00332 OSl 0.05191 0.05191 0.05191 -0.02199 -0.02199 -0.02199 OS2 0.10707 0.05471 0.04043 -0.07458 0.05539 -0.01269 Ow3 0.04677 0.04466 0.03166 -0.02773 0.00363 0.00831 Ow4 0.02554 0.03310 0.03763 0.00582 -0.00733 0.01307