data_global
_chemical_name_mineral 'Velikite'
loop_
_publ_author_name
'Kaplunnik L N'
'Pobedimskaya E A'
'Belov N V'
_journal_name_full 'Soviet Physics Crystallography'
_journal_volume 22 
_journal_year 1977
_journal_page_first 99
_journal_page_last 100
_publ_section_title
;
 Crystal structure of velikite Cu3.75Hg1.75Sn2S8
;
_database_code_amcsd 0015574
_chemical_compound_source 'Khaidarkan, Kyrgyzstan'
_chemical_formula_sum 'Cu1.6 Zn.28 Hg.875 Sn S4'
_cell_length_a 5.542
_cell_length_b 5.542
_cell_length_c 10.908
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 335.026
_exptl_crystal_density_diffrn      5.377
_symmetry_space_group_name_H-M 'I -4 2 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '-y,-x,z'
  '1/2-y,1/2-x,1/2+z'
  'y,-x,-z'
  '1/2+y,1/2-x,1/2-z'
  '-x,y,-z'
  '1/2-x,1/2+y,1/2-z'
  '-x,-y,z'
  '1/2-x,1/2-y,1/2+z'
  'y,x,z'
  '1/2+y,1/2+x,1/2+z'
  '-y,x,-z'
  '1/2-y,1/2+x,1/2-z'
  'x,-y,-z'
  '1/2+x,1/2-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
Cu   0.50000   0.00000   0.24980   0.40000   0.02360
Zn   0.50000   0.00000   0.24980   0.07000   0.02360
Hg   0.00000   0.00000   0.00000   0.87500   0.00662
Sn   0.00000   0.00000   0.50000   1.00000   0.01871
S   0.24350   0.24350   0.35330   1.00000   0.01717