data_MnCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.48
_cell_length_b   2.48
_cell_length_c   7.55
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnCu
_chemical_formula_sum   'Mn2 Cu2'
_cell_volume   46.61
_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
  Mn  Mn2  1  0.24  0.0  0.91  1.0
  Mn  Mn3  1  0.0  0.24  0.64  1.0
  Cu  Cu0  1  0.24  0.0  0.72  1.0
  Cu  Cu1  1  0.0  0.24  0.83  1.0

data_MnCu
_symmetry_space_group_name_H-M   C2/m
_cell_length_a   3.51
_cell_length_b   3.51
_cell_length_c   7.55
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   12
_chemical_formula_structural   MnCu
_chemical_formula_sum   'Mn4 Cu4'
_cell_volume   93.23
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x, y, -z'
  4  'x, -y, z'
  5  'x+1/2, y+1/2, z'
  6  '-x+1/2, -y+1/2, -z'
  7  '-x+1/2, y+1/2, -z'
  8  'x+1/2, -y+1/2, 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
  Mn  Mn0  4  0.12  0.5  0.64  1.0
  Cu  Cu1  4  0.12  0.5  0.45  1.0

Mn Mn Cu Cu
Mn Mn Cu Cu 0 3 o o o 1 2 o o o 2 3 o o o 
CuMn crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of four CuMn clusters. Mn(1) is bonded in a distorted single-bond geometry to one Cu(1) atom. The Mn(1)-Cu(1) bond length is 1.07 Å. Cu(1) is bonded in a distorted single-bond geometry to one Mn(1) atom.