#------------------------------------------------------------------------------
#$Date: 2012-02-28 14:14:52 +0200 (Tue, 28 Feb 2012) $
#$Revision: 35911 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/01/12/1011283.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_1011283
_chemical_name_systematic          'Tetraberyllium disilicate dihydroxide'
_chemical_name_mineral             'Bertrandite'
_chemical_compound_source          'from Pisek, Bohemia'
_chemical_formula_structural       'Be4 (Si2 O7) (O H)2'
_chemical_formula_sum            'Be4 H2 O9 Si2'
_[local]_cod_chemical_formula_sum_orig 'H2 Be4 O9 Si2'
_publ_section_title
;
The structure of bertrandite (H2 Be4 Si2 O9)
;
loop_
_publ_author_name
  'Ito, T'
  'West, J'
_journal_name_full
;
Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik,
Kristallchemie (-144,1977)
;
_journal_coden_ASTM                ZEKGAX
_journal_volume                    83
_journal_year                      1932
_journal_page_first                384
_journal_page_last                 393
_cell_length_a                     15.19
_cell_length_b                     8.67
_cell_length_c                     4.53
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       596.6
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'C c m 21'
_symmetry_Int_Tables_number        36
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  'x,-y,z'
  '-x,-y,1/2+z'
  '-x,y,1/2+z'
  '1/2+x,1/2+y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2+z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  O2-   -2.000
  Si4+   4.000
  Be2+   2.000
  H1+    1.000
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
  O1    O2-    4 a 0.065 0. 0. 1.  0 d
  O2    O2-    4 a 0.283 0. 0.5 1.  0 d
  O3    O2-    4 a 0.36 0. 0. 1.  0 d
  O4    O2-    8 b 0.095 0.155 0.5 1.  0 d
  O5    O2-    8 b 0.435 0.155 0.5 1.  0 d
  O6    O2-    8 b 0.215 0.155 0. 1.  1 d
  Si1   Si4+   4 a 0.074 0. 0.625 1.  0 d
  Si2   Si4+   4 a 0.36 0. 0.625 1.  0 d
  Be1   Be2+   8 b 0.215 0.155 0.375 1.  0 d
  Be2   Be2+   8 b 0.435 0.155 0.125 1.  0 d
  H1    H1+    8 b -1. -1. -1. 1.  0 dum
_cod_database_code 1011283