data_1010049
_chemical_name_systematic          'POTASSIUM HEPTAFLUORONIOBATE'
_chemical_formula_structural       'K2 NB F7'
_chemical_formula_sum              'F7 K2 Nb'
_publ_section_title
;
Structures of complex fluorides. Potassium heptafluocolumbate. The
Configuration of the heptafluocolumbate and heptafluortantalate
ions
;
_publ_author_name                  'Hoard, J L'
_journal_name_full                 'Journal of the American Chemical Society'
_journal_coden_ASTM                JACSAT
_journal_volume                    61
_journal_year                      1939
_journal_page_first                1252
_journal_page_last                 1259
_cell_length_a                     5.85
_cell_length_b                     12.67
_cell_length_c                     8.5
_cell_angle_alpha                  90
_cell_angle_beta                   90.(0)
_cell_angle_gamma                  90
_cell_volume                       630.0
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'P 1 21/c 1'
_symmetry_Int_Tables_number        14
_symmetry_cell_setting             monoclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
  'x,1/2-y,1/2+z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Nb5+   5.000
  K1+    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
  Nb1   Nb5+   4 e 0.266 0.128 0.223 1.  0 d
  K1    K1+    4 e 0.236 0.44 0.188 1.  0 d
  K2    K1+    4 e 0.757 0.28 0.445 1.  0 d
  F1    F1-    4 e 0.045 0.245 0.2 1.  0 d
  F2    F1-    4 e 0.455 0.255 0.205 1.  0 d
  F3    F1-    4 e 0.045 0.105 0.4 1.  0 d
  F4    F1-    4 e 0.455 0.11 0.41 1.  0 d
  F5    F1-    4 e 0.225 -0.025 0.215 1.  0 d
  F6    F1-    4 e 0.18 0.11 0.005 1.  0 d
  F7    F1-    4 e 0.55 0.075 0.125 1.  0 d