data_global
_chemical_name_mineral 'Weeksite'
loop_
_publ_author_name
'Stohl F V'
'Smith D K'
_journal_name_full 'American Mineralogist'
_journal_volume 66 
_journal_year 1981
_journal_page_first 610
_journal_page_last 625
_publ_section_title
;
 The crystal chemistry of the uranyl silicate minerals
;
_database_code_amcsd 0000839
_chemical_compound_source 'Anderson mine, Yavapai County, Arizona, USA'
_chemical_formula_sum 'U Si O7'
_cell_length_a 7.106
_cell_length_b 17.900
_cell_length_c 7.087
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 901.448
_exptl_crystal_density_diffrn      2.786
_symmetry_space_group_name_H-M 'A m m 2'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2+y,1/2+z'
  'x,-y,z'
  'x,1/2-y,1/2+z'
  '-x,y,z'
  '-x,1/2+y,1/2+z'
  '-x,-y,z'
  '-x,1/2-y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
U1   0.00000   0.19800   0.00000
Si   0.00000   0.13000   0.52300
O1   0.25000   0.30700   0.54600
O2   0.00000   0.18000   0.69300
O2b   0.00000   0.18000   0.30700
O3   0.19400   0.07100   0.48700
O4   0.00000   0.42900   0.47300