data_global _chemical_name_mineral 'Epididymite' loop_ _publ_author_name 'Pobedimskaya E A' 'Belov N V' _journal_name_full 'Doklady Akademii Nauk SSSR' _journal_volume 129 _journal_year 1959 _journal_page_first 900 _journal_page_last 903 _publ_section_title ; The crystal structure of epididymite: a new type of infinite silicooxygenous chains ; _database_code_amcsd 0012437 _chemical_formula_sum 'Na2 Be2 Si6 O17 H2' _cell_length_a 12.66 _cell_length_b 7.34 _cell_length_c 13.48 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1252.621 _exptl_crystal_density_diffrn 2.686 _symmetry_space_group_name_H-M 'P n a 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 Na1 0.19400 0.16700 0.49200 Be1 0.02500 0.21000 0.01700 Si1 0.16700 0.50000 0.15000 Si2 0.33400 0.20700 0.14200 Si3 0.15200 0.86000 0.13200 O1 0.40000 0.22500 0.05000 O2 0.11700 0.48300 0.25000 O3 0.38400 0.13000 0.25000 O4 0.07500 0.01700 0.07500 O5 0.11700 0.90000 0.25000 O6 0.07500 0.41000 0.07500 O7 0.27800 0.40000 0.15000 O8 0.20000 0.68400 0.09500 O9 0.26700 0.01000 0.12500 O-H10 0.06000 0.23400 0.58000