data_Ta(NbCu)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.4
_cell_length_b   6.4
_cell_length_c   6.4
_cell_angle_alpha   145.97
_cell_angle_beta   145.97
_cell_angle_gamma   48.89
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta(NbCu)2
_chemical_formula_sum   'Ta1 Nb2 Cu2'
_cell_volume   81.62
_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
  Ta  Ta4  1  0.0  0.0  0.0  1.0
  Nb  Nb2  1  0.0  0.87  0.91  1.0
  Nb  Nb3  1  0.87  0.0  0.91  1.0
  Cu  Cu0  1  0.0  0.0  0.92  1.0
  Cu  Cu1  1  0.0  0.0  0.73  1.0

data_Ta(NbCu)2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.29
_cell_length_b   5.29
_cell_length_c   6.4
_cell_angle_alpha   90.0
_cell_angle_beta   114.44
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ta(NbCu)2
_chemical_formula_sum   'Ta2 Nb4 Cu4'
_cell_volume   163.23
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  '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
  Ta  Ta0  2  0.0  0.0  0.0  1.0
  Nb  Nb1  4  0.48  0.44  0.04  1.0
  Cu  Cu2  2  0.23  0.5  0.73  1.0
  Cu  Cu3  2  0.42  0.5  0.92  1.0

Ta Nb Nb Cu Cu