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: 70 tons, P = 7.5 GPa
;
_database_code_amcsd 0004523
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Al2 Si O6 D2'
_cell_length_a 4.6658
_cell_length_b 8.8210
_cell_length_c 8.2573
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 339.846
_exptl_crystal_density_diffrn      3.559
_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   0.90600   0.13160   0.08800   1.00000   0.01330
Si   0.40400   0.94150   0.25000   1.00000   0.01330
O1   0.71800   0.02680   0.25000   1.00000   0.01010
O2   0.44300   0.75700   0.25000   1.00000   0.01010
O3   0.21930   0.99670   0.09130   1.00000   0.01010
O4   0.59340   0.25380   0.07100   1.00000   0.01010
D1   0.45600   0.18080   0.11700   0.59000   0.07800
D2   0.51900   0.27400   0.18000   0.41000   0.03700