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 0014034
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Na3 Al F6'
_cell_length_a 5.4054
_cell_length_b 5.5934
_cell_length_c 7.7672
_cell_angle_alpha 90
_cell_angle_beta 89.81
_cell_angle_gamma 90
_cell_volume 234.837
_exptl_crystal_density_diffrn      2.969
_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   0.51380   0.55200   0.25180   0.02913
Na1   0.50000   0.00000   0.50000   0.02026
Al1   0.50000   0.00000   0.00000   0.02280
F1   0.22550   0.17650   0.95300   0.02026
F2   0.33530   0.72850   0.93620   0.01773
F3   0.39700   0.95640   0.21820   0.01773