data_global _chemical_name_mineral 'Eudidymite' loop_ _publ_author_name 'Ito T' _journal_name_full 'American Mineralogist' _journal_volume 32 _journal_year 1947 _journal_page_first 442 _journal_page_last 453 _publ_section_title ; The structure of eudidymite (HNaBeSi3O8) Note: this structure does not make any sense ; _database_code_amcsd 43 _chemical_formula_sum 'Na Be Si3 O8 H' _cell_length_a 12.62 _cell_length_b 7.37 _cell_length_c 13.99 _cell_angle_alpha 90.0 _cell_angle_beta 103.72 _cell_angle_gamma 90.0 _cell_volume 1264.073 _exptl_crystal_density_diffrn 2.577 _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 Na1 0.0 0.03 0.25 Na2 0.5 0.03 0.25 Be 0.427 0.13 0.32 Si1 0.063 0.415 0.312 Si2 0.563 0.415 0.312 Si3 0.241 0.122 0.243 O1 0.052 0.03 0.396 O2 0.552 0.03 0.396 O3 0.0 0.275 0.25 O4 0.5 0.275 0.25 O5 0.161 0.03 0.19 O6 0.661 0.03 0.19 O7 0.208 0.315 0.372 O8 0.708 0.315 0.372 O-H 0.303 0.19 0.494