data_global _chemical_name_mineral 'Ameghinite' loop_ _publ_author_name 'Dal Negro A' 'Pozas J M M' 'Ungaretti L' _journal_name_full 'American Mineralogist' _journal_volume 60 _journal_year 1975 _journal_page_first 879 _journal_page_last 883 _publ_section_title ; The crystal structure of ameghinite ; _database_code_amcsd 470 _chemical_formula_sum 'Na B3 O7 H4' _cell_length_a 18.428 _cell_length_b 9.882 _cell_length_c 6.326 _cell_angle_alpha 90.0 _cell_angle_beta 104.4 _cell_angle_gamma 90.0 _cell_volume 1115.807 _exptl_crystal_density_diffrn 2.041 _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_U_iso_or_equiv Na 0.173 0.238 0.1032 0.02077 B1 0.3412 0.1716 0.4414 0.01355 B2 0.4028 0.3987 0.4959 0.01444 B3 0.4778 0.1994 0.4828 0.01418 O-h1 0.5494 0.1575 0.4964 0.02052 O-h2 0.3011 0.1606 0.215 0.01634 O-h3 0.3058 0.1016 0.5929 0.0171 O-h4 0.3986 0.5352 0.5164 0.02039 O5 0.4701 0.3401 0.4812 0.01874 O6 0.3437 0.3196 0.499 0.019 O7 0.4194 0.1177 0.48 0.01596 H1 0.561 0.059 0.505 0.038 H2 0.303 0.065 0.171 0.038 H3 0.252 0.13 0.56 0.038 H4 0.447 0.581 0.517 0.038 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 0.01801 0.02444 0.02413 0.00493 0.00896 0.00115 B1 0.00865 0.00965 0.0209 -4e-05 0.00224 0.00061 B2 0.01535 0.01465 0.01355 0.00092 0.00394 0.00226 B3 0.0127 0.01703 0.01543 -0.00257 0.00605 -0.00217 O-h1 0.01199 0.01377 0.03619 0.00203 0.00647 0.0031 O-h2 0.01401 0.01721 0.01655 -0.00158 0.00298 0.00167 O-h3 0.01453 0.01543 0.01976 -0.00337 0.00243 0.00078 O-h4 0.01514 0.01321 0.03645 0.00345 0.01005 0.00982 O5 0.01104 0.01134 0.03093 0.00066 0.00255 0.00396 O6 0.01154 0.01156 0.03057 0.0008 0.00193 -0.00186 O7 0.01175 0.0118 0.02642 0.00189 0.00678 0.00545