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#$Date: 2010-06-10 19:37:11 +0300 (Thu, 10 Jun 2010) $
#$Revision: 1212 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/1001720.cif $
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#
# 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_1001720
loop_
_publ_author_name
'Choisnet, J.'
'Nguyen, N.'
'Groult, D.'
'Raveau, B.'
_publ_section_title
;
 De nouveaux oxydes a reseau forme d'octahedres NbO6 (TaO6) et de groupes Si2O7:
 Les phases A3Ta6Si4O26 (A = Ba,Sr) et K6M6Si4O26 (M = Nb,Ta)
 Locality: synthetic
;
_journal_name_full               'Materials Research Bulletin'
_journal_page_first              887
_journal_page_last               894
_journal_volume                  11
_journal_year                    1976
_chemical_formula_structural     'Ba3 Nb6 Si4 O26'
_chemical_formula_sum            'Ba3 Nb6 O26 Si4'
_chemical_name_mineral           Belkovite
_chemical_name_systematic        'Barium niobate silicate *'
_symmetry_cell_setting           hexagonal
_symmetry_Int_Tables_number      189
_symmetry_space_group_name_H-M   'P -6 2 m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   8.981
_cell_length_b                   8.981
_cell_length_c                   7.84
_cell_volume                     547.6
_exptl_crystal_density_meas      4.56
_refine_ls_R_factor_all          0.046
_cod_database_code               1001720
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
-y,x-y,z
y-x,-x,z
x,y,-z
-y,x-y,-z
y-x,-x,-z
y,x,z
x-y,-y,z
-x,y-x,z
y,x,-z
x-y,-y,-z
-x,y-x,-z
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
Ba1 Ba2+ 3 g 0.593 0. 0.5 1. 0 d
Nb1 Nb5+ 6 i 0.238 0. 0.239 1. 0 d
Si1 Si4+ 4 h 0.3333 0.6667 0.203 1. 0 d
O1 O2- 2 c 0.3333 0.6667 0. 1. 0 d
O2 O2- 3 f 0.273 0. 0. 1. 0 d
O3 O2- 6 i 0.819 0. 0.236 1. 0 d
O4 O2- 12 l 0.489 0.183 0.284 1. 0 d
O5 O2- 3 g 0.227 0. 0.5 1. 0 d
loop_
_atom_type_symbol
_atom_type_oxidation_number
Ba2+ 2.000
Nb5+ 5.000
Si4+ 4.000
O2- -2.000
_amcsd_database_code             AMCSD#0012581