data_global
_chemical_name_mineral 'Walpurgite'
loop_
_publ_author_name
'Mereiter K'
_journal_name_full 'Tschermaks Mineralogische und Petrographische Mitteilungen'
_journal_volume 30 
_journal_year 1982
_journal_page_first 129
_journal_page_last 139
_publ_section_title
;
 The crystal structure of walpurgite,(UO2)Bi4O4(AsO4)2*2H2O
;
_database_code_amcsd 0015687
_chemical_compound_source 'Schneeberg, Germany'
_chemical_formula_sum 'U Bi4 As2 O16 H4'
_cell_length_a 7.135
_cell_length_b 10.426
_cell_length_c 5.494
_cell_angle_alpha 101.47
_cell_angle_beta 110.82
_cell_angle_gamma 88.20
_cell_volume 374.036
_exptl_crystal_density_diffrn      6.587
_symmetry_space_group_name_H-M 'P -1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
U   0.00000   0.00000   0.00000 ?
Bi1   0.21000   0.55881   0.94457 ?
Bi2   0.38368   0.34368   0.39357 ?
As  -0.03590   0.24000   0.57450 ?
O1   0.25020   0.02500   0.23570   0.02786
O2   0.12860   0.42140   0.12840   0.01140
O3   0.49070   0.50020   0.73830   0.01267
O4   0.12550   0.36270   0.60430   0.02026
O5  -0.23590   0.29800   0.64660   0.01773
O6  -0.10940   0.16480   0.25170   0.02153
O7   0.08650   0.13660   0.77650   0.02153
Wat8   0.51340   0.78470   0.06500   0.04433
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
U 0.01480 0.00760 0.01250 0.00130 0.00590 0.00110
Bi1 0.01480 0.01310 0.01270 0.00140 0.00630 0.00390
Bi2 0.01210 0.00880 0.01300 0.00150 0.00410 0.00140
As 0.01770 0.01100 0.01780 0.00300 0.00830 0.00310