data_Nb2Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.03
_cell_length_b   8.03
_cell_length_c   4.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   161.19
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2Cu
_chemical_formula_sum   'Nb4 Cu2'
_cell_volume   98.55
_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  0.31  0.85  0.56  1.0
  Nb  Nb3  1  0.31  0.79  0.56  1.0
  Nb  Nb4  1  0.31  0.21  0.19  1.0
  Nb  Nb5  1  0.31  0.15  0.19  1.0
  Cu  Cu0  1  0.31  0.5  0.56  1.0
  Cu  Cu1  1  0.31  0.5  0.19  1.0

data_Nb2Cu
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.62
_cell_length_b   4.74
_cell_length_c   8.03
_cell_angle_alpha   90.0
_cell_angle_beta   99.41
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Nb2Cu
_chemical_formula_sum   'Nb4 Cu2'
_cell_volume   98.55
_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  0.15  0.69  0.65  1.0
  Nb  Nb1  2  0.21  0.69  0.71  1.0
  Cu  Cu2  2  0.5  0.69  1.0  1.0

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