#------------------------------------------------------------------------------
#$Date: 2011-09-28 15:24:46 +0100 (Wed, 28 Sep 2011) $
#$Revision: 26848 $
#$URL: svn://www.crystallography.net/cod/cif/2/00/28/2002850.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_2002850
_chemical_name_systematic          'Distrontium diniobate'
_chemical_formula_structural       'Sr2 (Nb2 O7)'
_chemical_formula_sum              'Nb2 O7 Sr2'
_publ_section_title                'Zur Kristallstruktur von Sr2 Nb2 O7'
loop_
_publ_author_name
  'Scheunemann, K'
  'Mueller-Buschbaum, Hk'
_journal_name_full                 'Journal of Inorganic and Nuclear Chemistry'
_journal_volume                    37
_journal_year                      1975
_journal_page_first                1679
_journal_page_last                 1680
_cell_length_a                     26.64699(1200)
_cell_length_b                     7.936(4)
_cell_length_c                     5.705(3)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       1206.4
_cell_formula_units_Z              8
_symmetry_space_group_name_H-M     'P n a 21'
_symmetry_Int_Tables_number        33
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,-y,1/2+z'
  '1/2-x,1/2+y,1/2+z'
  '1/2+x,1/2-y,z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Nb5+   5.000
  Sr2+   2.000
  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+   4 a 0.09 0.1253 0.7752 1.  0 d
  Nb2   Nb5+   4 a 0.1954 0.1277 0.2482 1.  0 d
  Nb3   Nb5+   4 a 0.3107 0.1212 0.7467 1.  0 d
  Nb4   Nb5+   4 a 0.4139 0.1239 0.278 1.  0 d
  Sr1   Sr2+   4 a 0.05 0.3715 0.2948 1.  0 d
  Sr2   Sr2+   4 a 0.2027 0.368 0.7445 1.  0 d
  Sr3   Sr2+   4 a 0.3061 0.3656 0.2439 1.  0 d
  Sr4   Sr2+   4 a 0.4615 0.3737 0.8193 1.  0 d
  O1    O2-    4 a 0.036 0.13 0.561 1.  0 d
  O2    O2-    4 a 0.05 0.119 0.05 1.  0 d
  O3    O2-    4 a 0.095 0.374 0.764 1.  0 d
  O4    O2-    4 a 0.138 0.147 0.468 1.  0 d
  O5    O2-    4 a 0.158 0.12 0.908 1.  0 d
  O6    O2-    4 a 0.207 0.369 0.216 1.  0 d
  O7    O2-    4 a 0.241 0.133 0.532 1.  0 d
  O8    O2-    4 a 0.255 0.104 0.99 1.  0 d
  O9    O2-    4 a 0.302 0.376 0.732 1.  0 d
  O10   O2-    4 a 0.352 0.146 0.469 1.  0 d
  O11   O2-    4 a 0.366 0.092 0.966 1.  0 d
  O12   O2-    4 a 0.396 0.371 0.204 1.  0 d
  O13   O2-    4 a 0.452 0.138 0.552 1.  0 d
  O14   O2-    4 a 0.47 0.113 0.051 1.  0 d
_refine_ls_R_factor_all            0.076
_cod_database_code 2002850