data_1001698
_chemical_name_systematic
;
Sodium niobium phosphorus oxide (2.7/6/4/26)
;
_chemical_formula_structural       'Na2.667 Nb6 P4 O26'
_chemical_formula_sum              'Na2.667 Nb6 O26 P4'
_publ_section_title
;
Na2+x Nb6 P4 O26 : a novel niobium phosphate bronze isotypic of the m=3
member of the MPTBp family
;
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                    95
_journal_year                      1991
_journal_page_first                245
_journal_page_last                 252
_cell_length_a                     19.80499(100)
_cell_length_b                     14.3859(7)
_cell_length_c                     5.3960(4)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       1537.4
_cell_formula_units_Z              3
_symmetry_space_group_name_H-M     'P 21 21 2'
_symmetry_Int_Tables_number        18
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,-y,z'
  '1/2+x,1/2-y,-z'
  '1/2-x,1/2+y,-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Nb5+   4.889
  P5+    5.000
  Na1+   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+   2 a 0. 0. 0.2640(6) 1.  0 d
  Nb2   Nb5+   4 c 0.33090(5) 0.97971(6) 0.2372(5) 1.  0 d
  Nb3   Nb5+   4 c 0.11669(5) 0.10021(6) 0.7647(4) 1.  0 d
  Nb4   Nb5+   4 c 0.43601(4) 0.09682(6) 0.7459(5) 1.  0 d
  Nb5   Nb5+   4 c 0.77765(6) 0.11139(6) 0.7414(4) 1.  0 d
  P1    P5+    4 c 0.2158(1) 0.1654(2) 0.264(1) 1.  0 d
  P2    P5+    4 c 0.5369(1) 0.1787(2) 0.253(1) 1.  0 d
  P3    P5+    4 c 0.8842(1) 0.1708(2) 0.2332(9) 1.  0 d
  Na1   Na1+   4 c 0.0587(3) 0.2161(4) 0.242(3) 1.  0 d
  Na2   Na1+   4 c 0.3779(4) 0.2060(5) 0.246(4) 1.  0 d
  O1    O2-    4 c 0.0642(6) 0.0530(8) 0.023(3) 1.  0 d
  O2    O2-    4 c -0.0453(4) 0.1262(6) 0.271(3) 1.  0 d
  O3    O2-    4 c 0.0598(5) 0.0459(7) 0.517(2) 1.  0 d
  O4    O2-    4 c 0.2595(4) 0.0781(5) 0.273(3) 1.  0 d
  O5    O2-    4 c 0.3915(6) 0.0540(7) 0.474(2) 1.  0 d
  O6    O2-    4 c 0.2765(6) -0.0931(6) 0.026(2) 1.  0 d
  O7    O2-    4 c 0.4030(5) 0.8874(6) 0.214(2) 1.  0 d
  O8    O2-    4 c 0.3714(5) 0.0546(7) -0.022(2) 1.  0 d
  O9    O2-    4 c 0.2940(5) -0.0832(7) 0.536(2) 1.  0 d
  O10   O2-    4 c 0.0626(4) 0.2218(5) 0.765(3) 1.  0 d
  O11   O2-    4 c 0.1737(5) 0.1721(7) 0.493(2) 1.  0 d
  O12   O2-    4 c 0.1686(6) 0.1680(7) 0.036(2) 1.  0 d
  O13   O2-    4 c 0.1849(4) 0.0094(5) 0.757(4) 1.  0 d
  O14   O2-    4 c 0.3910(5) 0.2242(6) 0.712(2) 1.  0 d
  O15   O2-    2 b 0.5 0. 0.780(4) 1.  0 d
  O16   O2-    4 c 0.4855(5) 0.1653(7) 0.054(2) 1.  0 d
  O17   O2-    4 c 0.5085(5) 0.1655(7) 0.514(2) 1.  0 d
  O18   O2-    4 c 0.7627(4) 0.2516(5) 0.725(2) 1.  0 d
  O19   O2-    4 c 0.8577(5) 0.1543(6) -0.024(2) 1.  0 d
  O20   O2-    4 c 0.8400(5) 0.1315(7) 0.441(2) 1.  0 d
_refine_ls_R_factor_all            0.035