data_1001449
_chemical_name_systematic          'Tetrapotassium octaniobium pentaphosphate'
_chemical_formula_structural       'K4 Nb8 (P5 O34)'
_chemical_formula_sum              'K4 Nb8 O34 P5'
_publ_section_title
;
The niobium phosphate bronze K~5-x~Nb~8~P~5~O~34~, a new tunnel
structure, first member of the series (K~3~Nb~6~P~4~O~26~)~n~ .
KNb~2~PO~8~
;
loop_
_publ_author_name
  'Benabbas, A'
  'Borel, M M'
  'Grandin, A'
  'Leclaire, A'
  'Raveau, B'
_journal_name_full                 'Journal of Solid State Chemistry'
_journal_coden_ASTM                JSSCBI
_journal_volume                    87
_journal_year                      1990
_journal_page_first                360
_journal_page_last                 365
_cell_length_a                     13.904(6)
_cell_length_b                     6.453(3)
_cell_length_c                     20.64(1)
_cell_angle_alpha                  90
_cell_angle_beta                   125.05(1)
_cell_angle_gamma                  90
_cell_volume                       1516.0
_cell_formula_units_Z              2
_symmetry_space_group_name_H-M     'P 1 2/c 1'
_symmetry_Int_Tables_number        13
_symmetry_cell_setting             monoclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,y,1/2-z'
  '-x,-y,-z'
  'x,-y,1/2+z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Nb5+   4.880
  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 g 0.16613(2) 0.98280(4) 0.05406(1) 1.  0 d
  Nb2   Nb5+   4 g 0.24102(2) 0.99468(4) 0.26477(1) 1.  0 d
  Nb3   Nb5+   4 g 0.53830(2) 0.77407(4) 0.35353(1) 1.  0 d
  Nb4   Nb5+   4 g 0.74862(2) 0.77185(4) 0.56941(1) 1.  0 d
  P1    P5+    2 e 0. 0.1529(2) 0.25 1.  0 d
  P2    P5+    4 g 0.22103(5) 0.4980(1) 0.05104(3) 1.  0 d
  P3    P5+    4 g 0.30488(5) 0.4971(1) 0.31915(3) 1.  0 d
  K1    K1+    2 f 0.5 0.2743(2) 0.25 1.  0 d
  K2    K1+    4 g 0.4396(2) 0.7474(5) 0.5162(2) 0.5  0 d
  K3    K1+    4 g 0.0092(3) 0.6430(7) 0.1360(3) 0.45  0 d
  K4    K1+    4 g 0.0444(3) 0.504(1) 0.1279(2) 0.32  0 d
  K5    K1+    4 g 0.0571(8) 0.6856(9) 0.3357(5) 0.23  0 d
  O1    O2-    2 a 0. 0. 0. 1.  0 d
  O2    O2-    4 g 0.1895(2) -0.0175(4) 0.1619(1) 1.  0 d
  O3    O2-    4 g 0.3447(2) -0.0349(4) 0.1235(1) 1.  0 d
  O4    O2-    4 g 0.1734(2) -0.0525(4) -0.0330(1) 1.  0 d
  O5    O2-    4 g 0.1732(2) 0.2900(3) 0.0573(1) 1.  0 d
  O6    O2-    4 g 0.1544(2) 0.6721(3) 0.0618(1) 1.  0 d
  O7    O2-    4 g 0.4083(2) -0.0397(4) 0.3165(1) 1.  0 d
  O8    O2-    4 g 0.2768(2) 0.0353(4) 0.3778(1) 1.  0 d
  O9    O2-    4 g 0.0728(2) 0.0114(4) 0.2331(1) 1.  0 d
  O10   O2-    4 g 0.2509(2) 0.3056(3) 0.2636(1) 1.  0 d
  O11   O2-    4 g 0.2255(2) 0.6871(3) 0.2733(1) 1.  0 d
  O12   O2-    4 g 0.6055(2) 0.7849(4) 0.4697(1) 1.  0 d
  O13   O2-    4 g 0.4290(2) 0.5329(4) 0.3404(1) 1.  0 d
  O14   O2-    4 g 0.6475(2) 0.5147(4) 0.3830(1) 1.  0 d
  O15   O2-    2 f 0.5 0.7214(6) 0.25 1.  0 d
  O16   O2-    4 g 0.6910(2) 0.5382(4) 0.6059(1) 1.  0 d
  O17   O2-    4 g 0.8020(2) 0.5173(4) 0.5308(1) 1.  0 d
  O18   O2-    4 g 0.9181(2) 0.7127(4) 0.6770(1) 1.  0 d
_refine_ls_R_factor_all            0.029