data_global
_chemical_name_mineral 'Krohnkite'
loop_
_publ_author_name
'Dahlman B'
_journal_name_full 'Arkiv for Mineralogi och Geologi'
_journal_volume 1 
_journal_year 1952
_journal_page_first 339
_journal_page_last 366
_publ_section_title
;
 The crystal structures of krohnkite, CuNa2(SO4)2*2H2O and brandtite, MnCa2(AsO4)2*2H2O
;
_database_code_amcsd 0012043
_chemical_compound_source 'Chuquicamata, Chile'
_chemical_formula_sum 'Cu Na2 S2 O10 H4'
_cell_length_a 5.78
_cell_length_b 12.58
_cell_length_c 5.48
_cell_angle_alpha 90
_cell_angle_beta 71.5
_cell_angle_gamma 90
_cell_volume 377.873
_exptl_crystal_density_diffrn      2.968
_symmetry_space_group_name_H-M 'P 1 21/c 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Cu   0.00000   0.00000   0.00000
Na   0.42700   0.12600   0.23700
S   0.76600   0.11800   0.57800
O1   0.00000   0.16500   0.48000
O2   0.73300   0.04900   0.80300
O3   0.73300   0.04900   0.35800
O4   0.57100   0.19600   0.62200
Wat   0.17300   0.13000   0.98700