data_global
_amcsd_formula_title 'CuSe2'
loop_
_publ_author_name
'Heyding R D'
'Murray R M'
_journal_name_full 'Canadian Journal of Chemistry'
_journal_volume 54 
_journal_year 1976
_journal_page_first 841
_journal_page_last 848
_publ_section_title
;
 Crystal structures of Cu1.8Se, Cu3Se2, alpha- and gamma-CuSe, CuSe2, and CuSe2II
 Note: low-pressure polymorph, marcasite structure
;
_database_code_amcsd 0012161
_chemical_formula_sum 'Cu Se2'
_cell_length_a 5.005
_cell_length_b 6.182
_cell_length_c 3.740
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 115.719
_exptl_crystal_density_diffrn      6.356
_symmetry_space_group_name_H-M 'P n n m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,1/2+z'
  '1/2+x,1/2-y,1/2-z'
  'x,y,-z'
  '-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
Cu   0.00000   0.00000   0.00000   0.03926
Se   0.18400   0.38500   0.00000   0.02026