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: 46 tons, P = 4.7 GPa ; _database_code_amcsd 0004521 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Al2 Si O6 D2' _cell_length_a 4.6888 _cell_length_b 8.8624 _cell_length_c 8.3147 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 345.509 _exptl_crystal_density_diffrn 3.500 _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 0.13380 0.09000 1.00000 0.01050 Si 0.40200 0.94180 0.25000 1.00000 0.01050 O1 0.71200 0.02820 0.25000 1.00000 0.00670 O2 0.44500 0.75840 0.25000 1.00000 0.00670 O3 0.21750 0.99460 0.09070 1.00000 0.00670 O4 0.59220 0.25460 0.07050 1.00000 0.00670 D1 0.46200 0.18220 0.11900 0.59000 0.06400 D2 0.51600 0.27400 0.17720 0.41000 0.04800