data_global _chemical_name_mineral 'Uranophane - alpha' loop_ _publ_author_name 'Smith D K' 'Gruner J W' 'Lipscomb W N' _journal_name_full 'American Mineralogist' _journal_volume 42 _journal_year 1957 _journal_page_first 594 _journal_page_last 618 _publ_section_title ; The crystal structure of uranophane [Ca(H3O)2](UO2)2(SiO4)2.3H2O ; _database_code_amcsd 0000081 _chemical_compound_source 'Chinkolobwe deposits, Belgian Congo, Africa' _chemical_formula_sum 'U2 Si2 Ca O12' _cell_length_a 15.97 _cell_length_b 7.07 _cell_length_c 6.68 _cell_angle_alpha 90 _cell_angle_beta 97.3 _cell_angle_gamma 90 _cell_volume 748.111 _exptl_crystal_density_diffrn 3.393 _symmetry_space_group_name_H-M 'P 1 21 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-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 U1 0.25600 0.78700 0.13800 0.00443 U2 0.75600 0.71300 0.13800 0.00443 Si1 0.28200 0.28700 0.33500 0.00443 Si2 0.78200 0.21300 0.33500 0.00443 Ca 0.01900 0.75000 0.27100 0.00443 O1 0.37400 0.78700 0.13800 0.00443 O2 0.87400 0.71300 0.13800 0.00443 O3 0.13600 0.78700 0.12900 0.00443 O4 0.63600 0.71300 0.12900 0.00443 O5 0.25700 0.47700 0.19700 0.00443 O6 0.75700 0.40300 0.19700 0.00443 O7 0.25700 0.09700 0.19700 0.00443 O8 0.75700 0.02300 0.19700 0.00443 O9 0.23100 0.28700 0.53300 0.00443 O10 0.73100 0.21300 0.53300 0.00443 O11 0.38100 0.28700 0.43300 0.00443 O12 0.88100 0.21300 0.43300 0.00443