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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/9/9005794.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_9005794
_chemical_name 'Bertrandite'
loop_
_publ_author_name
'Hazen R M'
'Au A Y'
_journal_name_full "Physics and Chemistry of Minerals"
_journal_volume 13
_journal_year 1986
_journal_page_first 69
_journal_page_last 78
_publ_section_title
;
 High-pressure crystal chemistry of phenakite (Be2SiO4)
 and bertrandite (Be4Si2O7(OH)2)
 Sample: P = 23 kbar
 Note: x-coordinate of O2 altered
;
_chemical_formula_sum 'Be4 Si2 O9 H2'
_cell_length_a 8.641
_cell_length_b 15.051
_cell_length_c 4.5338
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 589.646
_symmetry_space_group_name_H-M 'C m c 21'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,z'
  '1/2-x,1/2+y,z'
  '-x,-y,1/2+z'
  '1/2-x,1/2-y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_Uiso_or_equiv
Be1   0.16790   0.05360   0.09400   0.00760
Be2   0.32460   0.22140   0.06100   0.00076
Si   0.32610   0.11350   0.65460   0.00659
O1   0.29390   0.12460   0.00000   0.01013
O2   0.20670   0.04380   0.49870   0.01267
O3   0.29480   0.20810   0.49040   0.01140
O4   0.00000   0.58210   0.58430   0.01140
O-H1   0.00000   0.76000   0.08260   0.01102
O-H2   0.00000   0.09160   0.07600   0.00760