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 0000470
_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
_cell_angle_beta 104.4
_cell_angle_gamma 90
_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   0.17300   0.23800   0.10320   0.02077
B1   0.34120   0.17160   0.44140   0.01355
B2   0.40280   0.39870   0.49590   0.01444
B3   0.47780   0.19940   0.48280   0.01418
O-h1   0.54940   0.15750   0.49640   0.02052
O-h2   0.30110   0.16060   0.21500   0.01634
O-h3   0.30580   0.10160   0.59290   0.01710
O-h4   0.39860   0.53520   0.51640   0.02039
O5   0.47010   0.34010   0.48120   0.01874
O6   0.34370   0.31960   0.49900   0.01900
O7   0.41940   0.11770   0.48000   0.01596
H1   0.56100   0.05900   0.50500   0.03800
H2   0.30300   0.06500   0.17100   0.03800
H3   0.25200   0.13000   0.56000   0.03800
H4   0.44700   0.58100   0.51700   0.03800
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 0.02090 -0.00004 0.00224 0.00061
B2 0.01535 0.01465 0.01355 0.00092 0.00394 0.00226
B3 0.01270 0.01703 0.01543 -0.00257 0.00605 -0.00217
O-h1 0.01199 0.01377 0.03619 0.00203 0.00647 0.00310
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 0.00080 0.00193 -0.00186
O7 0.01175 0.01180 0.02642 0.00189 0.00678 0.00545