data_global
_chemical_name_mineral 'Klockmannite'
loop_
_publ_author_name
'Berry L G'
_journal_name_full 'American Mineralogist'
_journal_volume 39
_journal_year 1954
_journal_page_first 504
_journal_page_last 509
_publ_section_title
;
 The crystal structure of covellite, CuS and klockmannite, CuSe
;
_database_code_amcsd 66
_chemical_formula_sum 'Cu Se'
_cell_length_a 3.938
_cell_length_b 3.938
_cell_length_c 17.25
_cell_angle_alpha 90.0
_cell_angle_beta 90.0
_cell_angle_gamma 120.0
_cell_volume 231.671
_exptl_crystal_density_diffrn  6.129
_symmetry_space_group_name_H-M 'P 63/m m c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-x+y,1/2+z'
  'x,x-y,1/2-z'
  '-x+y,-x,1/2-z'
  'x-y,x,1/2+z'
  '-y,-x,z'
  'y,x,-z'
  'y,-x+y,-z'
  '-y,x-y,z'
  'x-y,-y,1/2+z'
  '-x+y,y,1/2-z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  'x,x-y,z'
  '-x,-x+y,-z'
  'x-y,x,-z'
  '-x+y,-x,z'
  'y,x,1/2+z'
  '-y,-x,1/2-z'
  '-y,x-y,1/2-z'
  'y,-x+y,1/2+z'
  '-x+y,y,z'
  'x-y,-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Cu1   0.333333  0.666667  0.75
Cu2   0.333333  0.666667  0.107
Se1   0.333333  0.666667  0.25
Se2   0.0  0.0  0.066