data_global
_chemical_name_mineral 'Topaz'
loop_
_publ_author_name
'Komatsu K'
'Kagi H'
'Marshall W G'
'Kuribayashi T'
'Parise J B'
'Kudoh Y'
_journal_name_full 'American Mineralogist'
_journal_volume 93 
_journal_year 2008
_journal_page_first 217
_journal_page_last 227
_publ_section_title
;
 Pressure dependence of the hydrogen-bond geometry in topaz-OD from neutron
 powder diffraction
 Sample: 15 tons, P = 0.7 GPa
;
_database_code_amcsd 0004518
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Al2 Si O6 D2'
_cell_length_a 4.7248
_cell_length_b 8.9250
_cell_length_c 8.4100
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 354.640
_exptl_crystal_density_diffrn      3.410
_symmetry_space_group_name_H-M 'P b n m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
Al   0.90400   0.13470   0.08300   1.00000   0.01110
Si   0.40060   0.94010   0.25000   1.00000   0.01110
O1   0.71020   0.02880   0.25000   1.00000   0.00460
O2   0.44400   0.75800   0.25000   1.00000   0.00460
O3   0.21280   0.99270   0.09180   1.00000   0.00460
O4   0.59480   0.25060   0.06370   1.00000   0.00460
D1   0.45700   0.18700   0.12110   0.59000   0.06000
D2   0.52000   0.28300   0.16870   0.41000   0.04700