data_[Cu2Ni2Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Cu  1.9000  1.3500  0.8200
  Ni  1.9100  1.3500  0.7400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pmma]
_cell_length_a [5.2390]
_cell_length_b [3.7650]
_cell_length_c [6.6283]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [51]
_chemical_formula_structural [CuNiSe2]
_chemical_formula_sum '[Cu2 Ni2 Se4]'
_cell_volume [130.7399]
_cell_formula_units_Z [2]
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
[
  Cu  Cu0  2  0.0000  0.5000  0.0000  1.0
  Ni  Ni1  2  0.0000  0.0000  0.5000  1.0
  Se  Se2  2  0.2500  0.0000  0.1809  1.0
  Se  Se3  2  0.2500  0.5000  0.6524  1.0
]