data_Fe2CuSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.89
_cell_length_b   2.89
_cell_length_c   6.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   93.48
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe2CuSn
_chemical_formula_sum   'Fe2 Cu1 Sn1'
_cell_volume   57.88
_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
  Fe  Fe1  1  0.98  0.0  0.53  1.0
  Fe  Fe2  1  0.98  0.0  0.43  1.0
  Cu  Cu0  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.0  0.0  0.48  1.0

data_Fe2CuSn
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.2
_cell_length_b   3.96
_cell_length_c   6.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Fe2CuSn
_chemical_formula_sum   'Fe4 Cu2 Sn2'
_cell_volume   115.77
_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, -y, z'
  4  '-x, y, z'
  5  'x+1/2, y+1/2, z'
  6  '-x+1/2, -y+1/2, z'
  7  'x+1/2, -y+1/2, z'
  8  '-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
  Fe  Fe0  2  0.49  0.5  0.43  1.0
  Fe  Fe1  2  0.49  0.5  0.53  1.0
  Cu  Cu2  2  0.0  0.0  0.0  1.0
  Sn  Sn3  2  0.0  0.0  0.48  1.0

Fe Fe Cu Sn
Fe Fe Cu Sn 0 3 + o o 0 2 + o + 1 3 + o o 1 2 + o o 2 2 o + o 2 2 + o o 2 3 o o o 
Fe2CuSn crystallizes in the triclinic P1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a single-bond geometry to one Cu(1) and one Sn(1) atom. The Fe(1)-Cu(1) bond length is 3.30 Å. The Fe(1)-Sn(1) bond length is 0.33 Å. In the second Fe site, Fe(2) is bonded in a single-bond geometry to one Cu(1) and one Sn(1) atom. The Fe(2)-Cu(1) bond length is 3.01 Å. The Fe(2)-Sn(1) bond length is 0.33 Å. Cu(1) is bonded to one Fe(1), one Fe(2), and four equivalent Cu(1) atoms to form a mixture of corner and edge-sharing CuFe2Cu4 octahedra. The corner-sharing octahedra are not tilted. All Cu(1)-Cu(1) bond lengths are 2.89 Å. Sn(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one Fe(2) atom.