data_Na2FeSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.15
_cell_length_b   6.15
_cell_length_c   3.15
_cell_angle_alpha   100.53
_cell_angle_beta   100.53
_cell_angle_gamma   126.69
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2FeSn
_chemical_formula_sum   'Na2 Fe1 Sn1'
_cell_volume   87.36
_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
  Na  Na1  1  0.74  0.75  0.44  1.0
  Na  Na2  1  0.74  0.25  0.44  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.76  0.0  0.0  1.0

data_Na2FeSn
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.15
_cell_length_b   5.12
_cell_length_c   6.15
_cell_angle_alpha   111.77
_cell_angle_beta   100.53
_cell_angle_gamma   100.2
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2FeSn
_chemical_formula_sum   'Na2 Fe1 Sn1'
_cell_volume   87.36
_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
  Na  Na0  1  0.19  0.75  0.49  1.0
  Na  Na1  1  0.69  0.25  0.99  1.0
  Fe  Fe2  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  -0.0  0.0  0.76  1.0

Na Na Fe Sn
Na Na Fe Sn 0 3 o + + 0 2 + + + 1 3 o o o 2 3 - o o 