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: P = 0.0001 GPa ; _database_code_amcsd 0004516 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Al2 Si O6 D1.456 H.544' _cell_length_a 4.7279 _cell_length_b 8.9269 _cell_length_c 8.4214 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 355.429 _exptl_crystal_density_diffrn 3.392 _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 0.90620 0.13273 0.07970 1.00000 0.00530 Si 0.40200 0.94072 0.25000 1.00000 0.00155 O1 0.70980 0.02717 0.25000 1.00000 0.00350 O2 0.44460 0.75694 0.25000 1.00000 0.00350 O3 0.21408 0.99286 0.09325 1.00000 0.00350 O4 0.58996 0.25057 0.06533 1.00000 0.00359 D1 0.44030 0.19370 0.12220 0.43200 0.07440 D2 0.55600 0.29780 0.17200 0.29600 0.06530 H1 0.44030 0.19370 0.12220 0.14100 0.07440 H2 0.55600 0.29780 0.17200 0.13100 0.06530