data_global _amcsd_formula_title 'Pb6[Ge6O18].2H20' loop_ _publ_author_name 'Otto H H' 'Brandt H J' _journal_name_full 'European Journal of Mineralogy' _journal_volume 8 _journal_year 1996 _journal_page_first 301 _journal_page_last 310 _publ_section_title ; Crystal structure of Pb6[Ge6O18]2H2O, a lead cyclo-germanate similar to the mineral dioptase ; _database_code_amcsd 0006627 _chemical_formula_sum 'Pb3 Ge3 O10 H2' _cell_length_a 15.6476 _cell_length_b 15.6476 _cell_length_c 7.3119 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 1550.445 _exptl_crystal_density_diffrn 6.435 _symmetry_space_group_name_H-M 'R -3' loop_ _space_group_symop_operation_xyz 'x,y,z' '2/3+x,1/3+y,1/3+z' '1/3+x,2/3+y,2/3+z' 'y,-x+y,-z' '2/3+y,1/3-x+y,1/3-z' '1/3+y,2/3-x+y,2/3-z' '-x+y,-x,z' '2/3-x+y,1/3-x,1/3+z' '1/3-x+y,2/3-x,2/3+z' '-x,-y,-z' '2/3-x,1/3-y,1/3-z' '1/3-x,2/3-y,2/3-z' '-y,x-y,z' '2/3-y,1/3+x-y,1/3+z' '1/3-y,2/3+x-y,2/3+z' 'x-y,x,-z' '2/3+x-y,1/3+x,1/3-z' '1/3+x-y,2/3+x,2/3-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Pb 0.41190 0.28700 0.79830 0.01100 Ge 0.37750 0.48840 0.64400 0.01300 O1 0.27900 0.48300 0.76900 0.01300 O2 0.33500 0.41100 0.45700 0.01100 O3 0.43700 0.45400 0.80000 0.00800 Wat 0.00000 0.00000 0.30000 0.17000