#------------------------------------------------------------------------------
#$Date: 2008-01-26 15:05:32 +0200 (Sat, 26 Jan 2008) $
#$Revision: 19 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/1001855.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_1001855
_chemical_name_systematic          'Niobium(IV) niobium(V) phosphate(V)'
_chemical_formula_structural       'Nb2 (P O4)3'
_chemical_formula_sum              'Nb2 O12 P3'
_publ_section_title
;
A mixed-valence niobium phosphate with an empty nasicon structure: Nb2
(P O4)3
;
loop_
_publ_author_name
  'Leclaire, A'
  'Borel, M M'
  'Grandin, A'
  'Raveau, B'
_journal_name_full                 'Acta Crystallographica C (39,1983-)'
_journal_coden_ASTM                ACSCEE
_journal_volume                    45
_journal_year                      1989
_journal_page_first                699
_journal_page_last                 701
_cell_length_a                     8.6974(7)
_cell_length_b                     8.6974(7)
_cell_length_c                     22.12299(200)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  120
_cell_volume                       1449.3
_cell_formula_units_Z              6
_symmetry_space_group_name_H-M     'R -3 c H'
_symmetry_Int_Tables_number        167
_symmetry_cell_setting             trigonal
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-y,x-y,z'
  'y-x,-x,z'
  '-y,-x,1/2+z'
  'x,x-y,1/2+z'
  'y-x,y,1/2+z'
  '-x,-y,-z'
  'y,y-x,-z'
  'x-y,x,-z'
  'y,x,1/2-z'
  '-x,y-x,1/2-z'
  'x-y,-y,1/2-z'
  '1/3+x,2/3+y,2/3+z'
  '2/3+x,1/3+y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-y,2/3-x,1/6+z'
  '2/3-y,1/3-x,5/6+z'
  '1/3+x,2/3+x-y,1/6+z'
  '2/3+x,1/3+x-y,5/6+z'
  '1/3-x+y,2/3+y,1/6+z'
  '2/3-x+y,1/3+y,5/6+z'
  '1/3-x,2/3-y,2/3-z'
  '2/3-x,1/3-y,1/3-z'
  '1/3+y,2/3-x+y,2/3-z'
  '2/3+y,1/3-x+y,1/3-z'
  '1/3+x-y,2/3+x,2/3-z'
  '2/3+x-y,1/3+x,1/3-z'
  '1/3+y,2/3+x,1/6-z'
  '2/3+y,1/3+x,5/6-z'
  '1/3-x,2/3-x+y,1/6-z'
  '2/3-x,1/3-x+y,5/6-z'
  '1/3+x-y,2/3-y,1/6-z'
  '2/3+x-y,1/3-y,5/6-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Nb4+   4.500
  P5+    5.000
  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   Nb4+  12 c 0. 0. 0.14131(3) 1.  0 d
  P1    P5+   18 e 0.2821(2) 0. 0.25 1.  0 d
  O1    O2-   36 f 0.1692(5) -0.0289(6) 0.1943(2) 1.  0 d
  O2    O2-   36 f 0.2012(6) 0.1704(6) 0.0916(2) 1.  0 d
_refine_ls_R_factor_all            0.0347