#------------------------------------------------------------------------------
#$Date: 2008-01-14 00:15:36 +0200 (Mon, 14 Jan 2008) $
#$Revision: 14 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/1000502.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_1000502
_chemical_name_systematic          'Sodium gadolinium oxide bis(borate)'
_chemical_formula_structural       'Na2 Gd2 O (B O3)2'
_chemical_formula_sum              'B2 Gd2 Na2 O7'
_publ_section_title
;
Crystal structure of sodium rare earth oxyborates Na2 Ln2 (B O3)2 O(Ln
= Sm, Eu, and Gd) and optical analysis of Na2 Gd2 (B O3)2 O:Eu(3+)
;
loop_
_publ_author_name
  'Corbel, G'
  'Leblanc, M'
  'Antic-Fidancev, E'
  'Lemaitre-Blaise, M'
_journal_name_full                 'Journal of Solid State Chemistry'
_journal_coden_ASTM                JSSCBI
_journal_volume                    144
_journal_year                      1999
_journal_page_first                35
_journal_page_last                 44
_cell_length_a                     10.695(6)
_cell_length_b                     6.320(4)
_cell_length_c                     10.328(6)
_cell_angle_alpha                  90
_cell_angle_beta                   117.80(4)
_cell_angle_gamma                  90
_cell_volume                       617.5
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'P 1 21/c 1'
_symmetry_Int_Tables_number        14
_symmetry_cell_setting             monoclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
  'x,1/2-y,1/2+z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Gd3+   3.000
  Na1+   1.000
  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
  Gd1   Gd3+   4 e 0.18531(3) 0.08225(5) 0.08949(3) 1.  0 d
  Gd2   Gd3+   4 e 0.98249(3) 0.45948(5) 0.18103(3) 1.  0 d
  Na1   Na1+   4 e 0.5229(3) -0.0573(5) 0.2624(4) 1.  0 d
  Na2   Na1+   4 e 0.6094(4) 0.2622(7) 0.0469(4) 1.  0 d
  O1    O2-    4 e 0.9728(5) 0.1235(8) 0.0959(5) 1.  0 d
  O2    O2-    4 e 0.3179(5) -0.2556(8) 0.1359(6) 1.  0 d
  O3    O2-    4 e 0.1700(5) 0.2621(8) 0.3645(5) 1.  0 d
  O4    O2-    4 e 0.1504(5) 0.4594(8) 0.0877(6) 1.  0 d
  O5    O2-    4 e 0.3980(5) 0.162(1) 0.0552(5) 1.  0 d
  O6    O2-    4 e 0.8486(5) 0.2581(8) 0.2716(5) 1.  0 d
  O7    O2-    4 e 0.3727(6) 0.149(1) 0.3401(6) 1.  0 d
  B1    B3+    4 e 0.3183(7) 0.251(1) 0.0797(7) 1.  0 d
  B2    B3+    4 e 0.2097(7) -0.347(1) 0.1496(8) 1.  0 d
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_22
_atom_site_aniso_U_23
_atom_site_aniso_U_33
  Gd1   0.0062(1) -0.0001(1) 0.0027(1) 0.0038(2) .0000(1) 0.0061(2)
  Gd2   0.0067(1) 0.0003(1) 0.0032(1) 0.0033(1) .0000(1) 0.0055(2)
  Na1   0.013(2) .000(1) 0.005(2) 0.014(2) 0.001(2) 0.017(2)
  Na2   0.017(2) -0.002(2) 0.010(2) 0.029(2) 0.005(2) 0.018(2)
  O1    0.009(2) 0.001(2) 0.004(2) 0.006(2) -0.001(2) 0.007(2)
  O2    0.011(2) .000(2) 0.009(2) 0.009(2) .000(2) 0.016(2)
  O3    0.008(2) .000(2) 0.003(2) 0.010(2) 0.002(2) 0.007(2)
  O4    0.012(2) 0.001(2) 0.007(2) 0.005(2) 0.001(2) 0.012(2)
  O5    0.009(2) 0.001(2) 0.002(2) 0.015(2) 0.004(2) 0.007(2)
  O6    0.011(2) 0.001(2) 0.005(2) 0.008(2) 0.001(2) 0.009(2)
  O7    0.013(2) 0.001(2) 0.007(2) 0.016(2) -0.004(2) 0.012(2)
_refine_ls_R_factor_all            0.039