data_1001541
_chemical_name_systematic          'Potassium niobium silicophosphate *'
_chemical_formula_structural       'K4 Nb8 (Si P4 O34)'
_chemical_formula_sum              'K4 Nb8 O34 P4 Si'
_publ_section_title
;
A niobium silicophosphate belonging to the niobium phosphate
bronzeseries: K~4~Nb~8~P~4~SiO~34~
;
loop_
_publ_author_name
  'Leclaire, A'
  'Borel, M M'
  'Chardon, J'
  'Grandin, A'
  'Raveau, B'
_journal_name_full                 'Acta Crystallographica C (39,1983-)'
_journal_coden_ASTM                ACSCEE
_journal_volume                    48
_journal_year                      1992
_journal_page_first                1744
_journal_page_last                 1747
_cell_length_a                     10.6050(9)
_cell_length_b                     10.6050(9)
_cell_length_c                     6.4099(5)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       720.9
_cell_formula_units_Z              1
_symmetry_space_group_name_H-M     'P -4 m 2'
_symmetry_Int_Tables_number        115
_symmetry_cell_setting             tetragonal
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-y,x,-z'
  '-x,-y,z'
  'y,-x,-z'
  '-x,y,z'
  'y,x,-z'
  'x,-y,z'
  '-y,-x,-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Nb5+   5.000
  Si4+   4.000
  P5+    5.000
  K1+    1.000
  O2-   -2.000
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 k 0.5 0.1847(1) 0.2035(1) 1.  0 d
  Nb2   Nb5+   4 h 0.17750(5) 0.17750(5) 0. 1.  0 d
  Si1   Si4+   1 b 0.5 0.5 0. 1.  0 d
  P1    P5+    4 i 0.2397(1) 0.2397(1) 0.5 1.  0 d
  K1    K1+    1 d 0. 0. 0.5 1.  0 d
  K2    K1+    2 g 0. 0.5 0.2923(8) 1.  0 d
  K3    K1+    1 c 0.5 0.5 0.5 1.  0 d
  O1    O2-    2 g 0.5 0. 0.261(2) 1.  0 d
  O2    O2-    8 l 0.3638(4) 0.1747(5) 0.0215(8) 1.  0 d
  O3    O2-    8 l 0.3790(4) 0.2154(5) 0.4530(7) 1.  0 d
  O4    O2-    4 k 0.5 0.3819(7) 0.145(1) 1.  0 d
  O5    O2-    4 j 0.1756(8) 0. 0.032(1) 1.  0 d
  O6    O2-    8 l 0.1586(4) 0.1982(4) 0.3115(6) 1.  0 d
_refine_ls_R_factor_all            0.03