data_Cu2NiSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.1
_cell_length_b   3.28
_cell_length_c   5.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2NiSe
_chemical_formula_sum   'Cu2 Ni1 Se1'
_cell_volume   53.61
_cell_formula_units_Z   1
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  1  0.0  0.0  0.14  1.0
  Cu  Cu1  1  0.55  0.64  0.3  1.0
  Ni  Ni2  1  0.0  0.0  0.69  1.0
  Se  Se3  1  0.55  0.64  0.78  1.0

data_Cu2NiSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.1
_cell_length_b   3.28
_cell_length_c   5.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2NiSe
_chemical_formula_sum   'Cu2 Ni1 Se1'
_cell_volume   53.61
_cell_formula_units_Z   1
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  1  0.0  0.0  0.14  1.0
  Cu  Cu1  1  0.55  0.64  0.3  1.0
  Ni  Ni2  1  0.0  0.0  0.69  1.0
  Se  Se3  1  0.55  0.64  0.78  1.0

Cu Cu Ni Se
NiCu2Se crystallizes in the triclinic P1 space group. Ni(1) is bonded in a 2-coordinate geometry to two equivalent Cu(1) and two equivalent Se(1) atoms. There is one shorter (2.36 Å) and one longer (2.92 Å) Ni(1)-Cu(1) bond length. There is one shorter (1.88 Å) and one longer (2.11 Å) Ni(1)-Se(1) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 9-coordinate geometry to two equivalent Ni(1), four equivalent Cu(2), and three equivalent Se(1) atoms. There are a spread of Cu(1)-Cu(2) bond distances ranging from 2.01-2.83 Å. There are a spread of Cu(1)-Se(1) bond distances ranging from 2.66-3.18 Å. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to four equivalent Cu(1) and two equivalent Se(1) atoms. There is one shorter (2.51 Å) and one longer (2.76 Å) Cu(2)-Se(1) bond length. Se(1) is bonded in a 2-coordinate geometry to two equivalent Ni(1), two equivalent Cu(2), and three equivalent Cu(1) atoms.