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#$Date: 2008-01-14 00:15:36 +0200 (Mon, 14 Jan 2008) $
#$Revision: 14 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/1001007.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_1001007
_chemical_name_systematic          'Tripotassium boro-niobate *'
_chemical_formula_structural       'K3 B2 NB3 O12'
_chemical_formula_sum              'B2 K3 Nb3 O12'
_publ_section_title
;
Nouvelles structures a tunnels de section pentagonale K~3~ Nb~3~ B~2~
O~12~ et K~3~ Ta~3~ B~2~ O~12~
;
loop_
_publ_author_name
  'Choisnet, J'
  'Groult, D'
  'Raveau, B'
  'Gasperin, M'
_journal_name_full                 'Acta Crystallographica B (24,1968-38,1982)'
_journal_coden_ASTM                ACBCAR
_journal_volume                    33
_journal_year                      1977
_journal_page_first                1841
_journal_page_last                 1845
_cell_length_a                     8.753(5)
_cell_length_b                     8.753(5)
_cell_length_c                     3.966(1)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  120
_cell_volume                       263.1
_cell_formula_units_Z              1
_exptl_crystal_density_meas        3.85
_symmetry_space_group_name_H-M     'P 3 1 m'
_symmetry_Int_Tables_number        157
_symmetry_cell_setting             trigonal
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-y,x-y,z'
  'y-x,-x,z'
  'y,x,z'
  '-x,y-x,z'
  'x-y,-y,z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  K1+    1.000
  Nb5+   5.000
  O2-   -2.000
  B3+    3.000
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
  K1    K1+    3 c 0.5964(9) 0. 0.4989(22) 1.  0 d
  Nb1   Nb5+   3 c 0.2463(3) 0. 0. 1.  0 d
  O1    O2-    3 c 0.8179(35) 0. -0.0076(75) 1.  0 d
  O2    O2-    3 c 0.2606(29) 0. 0.4930(121) 1.  0 d
  O3    O2-    6 d 0.5030(28) 0.1854(20) -0.0169(57) 1.  0 d
  B1    B3+    2 b 0.3333 0.6667 -0.0188(134) 1.  0 d
_refine_ls_R_factor_all            0.08