data_CuNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.33
_cell_length_b   4.33
_cell_length_c   4.33
_cell_angle_alpha   99.67
_cell_angle_beta   99.67
_cell_angle_gamma   33.54
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuNi3
_chemical_formula_sum   'Cu1 Ni3'
_cell_volume   44.21
_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  0.77  0.0  0.13  1.0
  Ni  Ni1  1  0.51  0.0  0.21  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  Ni  Ni3  1  0.02  0.0  0.05  1.0

data_CuNi3
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.5
_cell_length_b   4.33
_cell_length_c   4.33
_cell_angle_alpha   99.67
_cell_angle_beta   106.77
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuNi3
_chemical_formula_sum   'Cu1 Ni3'
_cell_volume   44.21
_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  0.13  0.77  1.0
  Ni  Ni1  1  0.0  0.0  0.0  1.0
  Ni  Ni2  1  0.0  0.05  0.02  1.0
  Ni  Ni3  1  0.0  0.21  0.51  1.0

Cu Ni Ni Ni
Ni3Cu crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one Ni3Cu cluster. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted single-bond geometry to one Cu(1) atom. The Ni(1)-Cu(1) bond length is 1.21 Å. In the second Ni site, Ni(2) is bonded in a single-bond geometry to one Ni(3) and one Cu(1) atom. The Ni(2)-Ni(3) bond length is 0.24 Å. The Ni(2)-Cu(1) bond length is 1.24 Å. In the third Ni site, Ni(3) is bonded in a single-bond geometry to one Ni(2) and one Cu(1) atom. The Ni(3)-Cu(1) bond length is 1.21 Å. Cu(1) is bonded in a 3-coordinate geometry to one Ni(1), one Ni(2), and one Ni(3) atom.