data_Nb3Sn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.96
_cell_length_b   4.96
_cell_length_c   4.96
_cell_angle_alpha   126.9
_cell_angle_beta   126.9
_cell_angle_gamma   78.41
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb3Sn
_chemical_formula_sum   'Nb3 Sn1'
_cell_volume   75.59
_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
  Nb  Nb0  1  0.0  0.22  0.92  1.0
  Nb  Nb1  1  0.0  0.0  0.0  1.0
  Nb  Nb2  1  0.22  0.0  0.92  1.0
  Sn  Sn3  1  0.0  0.0  0.84  1.0

data_Nb3Sn
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.27
_cell_length_b   6.27
_cell_length_c   4.96
_cell_angle_alpha   90.0
_cell_angle_beta   129.21
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Nb3Sn
_chemical_formula_sum   'Nb6 Sn2'
_cell_volume   151.18
_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
  Nb  Nb0  4  0.19  0.11  0.3  1.0
  Nb  Nb1  2  0.0  0.0  0.0  1.0
  Sn  Sn2  2  0.16  0.0  0.16  1.0

Nb Nb Nb Sn
Nb Nb Nb Sn 0 3 o o o 1 3 o o - 2 3 o o o 