data_global
_chemical_name_mineral 'Cryolite'
loop_
_publ_author_name
'Ross K C'
'Mitchell R H'
'Chakhmouradian A R'
_journal_name_full 'Journal of Solid State Chemistry'
_journal_volume 172 
_journal_year 2003
_journal_page_first 95
_journal_page_last 101
_publ_section_title
;
 The crystal structure of synthetic simmonsite, Na2LiAlF6
;
_database_code_amcsd 0014033
_chemical_compound_source 'natural'
_chemical_formula_sum 'Na3 Al F6'
_cell_length_a 5.4058
_cell_length_b 5.5926
_cell_length_c 7.7699
_cell_angle_alpha 90
_cell_angle_beta 90.195
_cell_angle_gamma 90
_cell_volume 234.902
_exptl_crystal_density_diffrn      2.968
_symmetry_space_group_name_H-M 'P 1 21/n 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-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
Na2   0.51190   0.94890   0.24880   0.03040
Na1   0.00000   0.00000   0.50000   0.01773
Al   0.00000   0.00000   0.00000   0.01140
F1   0.10360   0.04420   0.21960   0.01646
F2   0.72570   0.17410   0.04250   0.02406
F3   0.16930   0.26830  -0.06090   0.02280