data_global _chemical_name_mineral 'Tunisite' loop_ _publ_author_name 'Effenberger H' 'Kluger F' 'Pertlik F' 'Zemann J' _journal_name_full 'Tschermaks Mineralogische und Petrographische Mitteilungen' _journal_volume 28 _journal_year 1981 _journal_page_first 65 _journal_page_last 77 _publ_section_title ; Tunisit: kristallstruktur und revision der chemischen formel ; _database_code_amcsd 0015681 _chemical_formula_sum 'Na Ca2 Al4 C4 O20 H8 Cl' _cell_length_a 11.1983 _cell_length_b 11.1983 _cell_length_c 6.5637 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 823.101 _exptl_crystal_density_diffrn 2.512 _symmetry_space_group_name_H-M 'P 4/n m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-y,1/2-x,z' '1/2+y,1/2+x,-z' '1/2+y,-x,-z' '1/2-y,x,z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2+x,1/2+y,-z' '1/2-x,1/2-y,z' 'y,x,z' '-y,-x,-z' '-y,1/2+x,-z' 'y,1/2-x,z' '1/2-x,y,z' '1/2+x,-y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Na 0.25000 0.25000 0.93704 0.03230 Ca 0.00000 0.00000 0.00000 0.03242 Al 0.40479 -0.40479 0.50000 0.00659 C 0.25000 0.51396 0.15653 0.00849 O_c3 0.46093 0.64970 0.75908 0.01140 O_c4 0.25000 0.46534 0.98187 0.01596 O_h1 0.25000 0.90696 0.59918 0.00937 O_h2 0.43878 0.43878 0.60715 0.00975 H1 0.25000 0.93400 0.72000 0.00975 H2 0.39100 0.39100 0.57700 0.02799 Cl 0.25000 0.25000 0.46863 0.03116 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 0.02084 0.02084 0.05487 0.00000 0.00000 0.00000 Ca 0.03678 0.03678 0.02324 0.02948 -0.02249 -0.02249 Al 0.00616 0.00616 0.00746 0.00000 -0.00007 -0.00007 C 0.00800 0.00858 0.00869 0.00000 0.00000 0.00082 O_c3 0.01690 0.00737 0.00980 -0.00089 -0.00313 -0.00034 O_c4 0.01855 0.02160 0.00740 0.00000 0.00000 -0.00529 O_h1 0.00781 0.01404 0.00598 0.00000 0.00000 -0.00153 O_h2 0.00750 0.00750 0.01408 -0.00089 0.00034 0.00034 Cl 0.01277 0.01277 0.06731 0.00000 0.00000 0.00000