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