data_global _chemical_name_mineral 'Eudidymite' loop_ _publ_author_name 'Fang J H' 'Robinson P D' 'Ohya Y' _journal_name_full 'American Mineralogist' _journal_volume 57 _journal_year 1972 _journal_page_first 1345 _journal_page_last 1354 _publ_section_title ; Redetermination of the crystal structure of eudidymite and its dimorphic relationship to epididymite ; _database_code_amcsd 0000293 _chemical_formula_sum 'Na Be Si3 O8 H' _cell_length_a 12.63 _cell_length_b 7.38 _cell_length_c 14.02 _cell_angle_alpha 90 _cell_angle_beta 103.72 _cell_angle_gamma 90 _cell_volume 1269.508 _exptl_crystal_density_diffrn 2.566 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_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,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Na 0.02870 0.34050 0.92820 0.03255 Be 0.16770 0.32280 0.49690 0.01368 Si1 0.20380 0.01990 0.64160 0.00963 Si2 0.25180 0.10270 0.86650 0.00988 Si3 0.02970 0.09330 0.36180 0.01039 O1 0.07320 0.03290 0.62660 0.01355 O2 0.24010 0.18000 0.11520 0.01887 O3 0.24100 0.16500 0.57150 0.01507 O4 0.23680 0.43920 0.24470 0.02090 O5 0.15490 0.49840 0.05580 0.01469 O6 0.12920 0.05190 0.87550 0.01418 O7 0.00000 0.17320 0.25000 0.01912 O8 0.05260 0.25610 0.43730 0.01659 Wat 0.00000 0.43220 0.75000 0.03838