data_1010380
_chemical_name_systematic          'Potassium hydrogendifluoride'
_chemical_formula_structural       'K H F2'
_chemical_formula_sum              'H F2 K'
_publ_section_title
;
A Redetermination of the Fluorine - Fluorine Distance in Potassium
Bifluoride
;
loop_
_publ_author_name
  'Helmholz, L'
  'Rogers, M T'
_journal_name_full                 'Journal of the American Chemical Society'
_journal_coden_ASTM                JACSAT
_journal_volume                    61
_journal_year                      1939
_journal_page_first                2590
_journal_page_last                 2592
_cell_length_a                     5.67
_cell_length_b                     5.67
_cell_length_c                     6.81
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       218.9
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'I 4/m c m'
_symmetry_Int_Tables_number        140
_symmetry_cell_setting             tetragonal
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,-y,z'
  'x,-y,1/2+z'
  '-x,y,1/2+z'
  '-y,x,z'
  'y,-x,z'
  'y,x,1/2+z'
  '-y,-x,1/2+z'
  '-x,-y,-z'
  'x,y,-z'
  '-x,y,1/2-z'
  'x,-y,1/2-z'
  'y,-x,-z'
  '-y,x,-z'
  '-y,-x,1/2-z'
  'y,x,1/2-z'
  '1/2+x,1/2+y,1/2+z'
  '1/2-x,1/2-y,1/2+z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,z'
  '1/2-y,1/2+x,1/2+z'
  '1/2+y,1/2-x,1/2+z'
  '1/2+y,1/2+x,z'
  '1/2-y,1/2-x,z'
  '1/2-x,1/2-y,1/2-z'
  '1/2+x,1/2+y,1/2-z'
  '1/2-x,1/2+y,-z'
  '1/2+x,1/2-y,-z'
  '1/2+y,1/2-x,1/2-z'
  '1/2-y,1/2+x,1/2-z'
  '1/2-y,1/2-x,-z'
  '1/2+y,1/2+x,-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  K1+    1.000
  H1+    1.000
  F1-   -1.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  K1    K1+    4 ? -1. -1. -1. 1.  0 dum
  H1    H1+    4 d 0. 0.5 0. 1.  0 d
  F1    F1-    8 h 0.1408(3) 0.6408(3) 0. 1.  0 d