data_Cr2Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.28
_cell_length_b   7.28
_cell_length_c   4.23
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   161.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cr2Cu
_chemical_formula_sum   'Cr4 Cu2'
_cell_volume   71.31
_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
  Cr  Cr0  1  0.17  0.34  0.17  1.0
  Cr  Cr1  1  0.17  0.66  0.06  1.0
  Cr  Cr2  1  0.17  0.49  0.06  1.0
  Cr  Cr3  1  0.17  0.51  0.17  1.0
  Cu  Cu4  1  0.17  0.14  0.17  1.0
  Cu  Cu5  1  0.17  0.86  0.06  1.0

data_Cr2Cu
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.34
_cell_length_b   4.23
_cell_length_c   7.28
_cell_angle_alpha   90.0
_cell_angle_beta   99.27
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Cr2Cu
_chemical_formula_sum   'Cr4 Cu2'
_cell_volume   71.31
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Cr  Cr0  2  0.34  0.44  0.84  1.0
  Cr  Cr1  2  0.49  0.56  0.99  1.0
  Cu  Cu2  2  0.14  0.44  0.64  1.0

Cr Cr Cr Cr Cu Cu
CuCr2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one Cr cluster and two CuCr clusters. In the Cr cluster, Cr(2) is bonded in a single-bond geometry to one Cr(2) atom. The Cr(2)-Cr(2) bond length is 0.54 Å. In each CuCr cluster, Cr(1) is bonded in a 1-coordinate geometry to one Cu(1) atom. The Cr(1)-Cu(1) bond length is 1.47 Å. Cu(1) is bonded in a distorted single-bond geometry to one Cr(1) atom.