data_Al2Sn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.64
_cell_length_b   5.64
_cell_length_c   9.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al2Sn
_chemical_formula_sum   'Al8 Sn4'
_cell_volume   247.88
_cell_formula_units_Z   4
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
  Al  Al0  1  0.0  0.0  0.5  1.0
  Al  Al1  1  0.0  0.0  0.0  1.0
  Al  Al2  1  0.38  0.05  0.76  1.0
  Al  Al3  1  0.43  0.83  0.25  1.0
  Al  Al4  1  0.62  0.05  0.76  1.0
  Al  Al5  1  0.0  0.65  0.76  1.0
  Al  Al6  1  0.82  0.23  0.25  1.0
  Al  Al7  1  0.2  0.83  0.25  1.0
  Sn  Sn8  1  0.82  0.63  0.1  1.0
  Sn  Sn9  1  0.0  0.25  0.59  1.0
  Sn  Sn10  1  0.0  0.25  0.91  1.0
  Sn  Sn11  1  0.82  0.63  0.42  1.0

data_Al2Sn
_symmetry_space_group_name_H-M   Pm
_cell_length_a   5.64
_cell_length_b   9.01
_cell_length_c   5.64
_cell_angle_alpha   90.0
_cell_angle_beta   120.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   Al2Sn
_chemical_formula_sum   'Al8 Sn4'
_cell_volume   247.88
_cell_formula_units_Z   4
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
  Al  Al0  2  0.0  0.25  0.0  1.0
  Al  Al1  1  0.0  0.0  0.65  1.0
  Al  Al2  1  0.2  0.5  0.83  1.0
  Al  Al3  1  0.38  0.0  0.05  1.0
  Al  Al4  1  0.43  0.5  0.83  1.0
  Al  Al5  1  0.62  0.0  0.05  1.0
  Al  Al6  1  0.82  0.5  0.23  1.0
  Sn  Sn7  2  0.0  0.17  0.25  1.0
  Sn  Sn8  2  0.82  0.34  0.63  1.0

Al Al Al Al Al Al Al Al Sn Sn Sn Sn
Al2Sn crystallizes in the triclinic P1 space group. There are eight inequivalent Al sites. In the first Al site, Al(1) is bonded in a bent 150 degrees geometry to one Sn(2) and one Sn(4) atom. The Al(1)-Sn(2) bond length is 1.63 Å. The Al(1)-Sn(4) bond length is 1.98 Å. In the second Al site, Al(2) is bonded in a bent 150 degrees geometry to one Sn(1) and one Sn(3) atom. The Al(2)-Sn(1) bond length is 2.01 Å. The Al(2)-Sn(3) bond length is 1.63 Å. In the third Al site, Al(3) is bonded in a distorted bent 120 degrees geometry to one Al(5) and one Al(6) atom. The Al(3)-Al(5) bond length is 1.30 Å. The Al(3)-Al(6) bond length is 2.21 Å. In the fourth Al site, Al(4) is bonded in a 4-coordinate geometry to one Al(7), one Al(8), one Sn(1), and one Sn(4) atom. The Al(4)-Al(7) bond length is 2.21 Å. The Al(4)-Al(8) bond length is 1.30 Å. The Al(4)-Sn(1) bond length is 3.23 Å. The Al(4)-Sn(4) bond length is 3.27 Å. In the fifth Al site, Al(5) is bonded in a 3-coordinate geometry to one Al(3), one Sn(2), and one Sn(3) atom. The Al(5)-Sn(2) bond length is 2.41 Å. The Al(5)-Sn(3) bond length is 2.35 Å. In the sixth Al site, Al(6) is bonded in a 3-coordinate geometry to one Al(3), one Sn(2), and one Sn(3) atom. The Al(6)-Sn(2) bond length is 2.71 Å. The Al(6)-Sn(3) bond length is 2.67 Å. In the seventh Al site, Al(7) is bonded in a 3-coordinate geometry to one Al(4), one Sn(1), and one Sn(4) atom. The Al(7)-Sn(1) bond length is 2.67 Å. The Al(7)-Sn(4) bond length is 2.71 Å. In the eighth Al site, Al(8) is bonded in a 3-coordinate geometry to one Al(4), one Sn(1), and one Sn(4) atom. The Al(8)-Sn(1) bond length is 2.35 Å. The Al(8)-Sn(4) bond length is 2.41 Å. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 3-coordinate geometry to one Al(2), one Al(4), one Al(7), and one Al(8) atom. In the second Sn site, Sn(2) is bonded in a 1-coordinate geometry to one Al(1), one Al(5), and one Al(6) atom. In the third Sn site, Sn(3) is bonded in a 1-coordinate geometry to one Al(2), one Al(5), and one Al(6) atom. In the fourth Sn site, Sn(4) is bonded in a 3-coordinate geometry to one Al(1), one Al(4), one Al(7), and one Al(8) atom.