data_Nb2Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.56
_cell_length_b   5.56
_cell_length_c   7.13
_cell_angle_alpha   104.53
_cell_angle_beta   104.53
_cell_angle_gamma   27.82
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2Cu
_chemical_formula_sum   'Nb4 Cu2'
_cell_volume   99.24
_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
  Nb  Nb2  1  0.75  0.0  0.21  1.0
  Nb  Nb3  1  0.54  0.0  0.65  1.0
  Nb  Nb4  1  0.41  0.0  0.23  1.0
  Nb  Nb5  1  0.2  0.0  0.67  1.0
  Cu  Cu0  1  0.03  0.0  0.95  1.0
  Cu  Cu1  1  0.92  0.0  0.93  1.0

data_Nb2Cu
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.67
_cell_length_b   5.56
_cell_length_c   7.13
_cell_angle_alpha   104.53
_cell_angle_beta   90.0
_cell_angle_gamma   103.91
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Nb2Cu
_chemical_formula_sum   'Nb4 Cu2'
_cell_volume   99.24
_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
  Nb  Nb0  2  0.0  0.22  0.73  1.0
  Nb  Nb1  2  0.0  0.44  0.29  1.0
  Cu  Cu2  2  0.0  0.05  0.01  1.0

Nb Nb Nb Nb Cu Cu
Nb Nb Nb Nb Cu Cu 0 2 o o o 1 3 o o o 4 5 - o o 