data_Al3I
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.93
_cell_length_b   5.93
_cell_length_c   5.93
_cell_angle_alpha   137.3
_cell_angle_beta   137.3
_cell_angle_gamma   61.98
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al3I
_chemical_formula_sum   'Al3 I1'
_cell_volume   94.63
_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
  Al  Al0  1  0.16  0.0  0.54  1.0
  Al  Al1  1  0.0  0.16  0.54  1.0
  Al  Al2  1  0.0  0.0  0.0  1.0
  I  I3  1  0.0  0.0  0.08  1.0

data_Al3I
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.1
_cell_length_b   6.1
_cell_length_c   5.93
_cell_angle_alpha   90.0
_cell_angle_beta   120.99
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Al3I
_chemical_formula_sum   'Al6 I2'
_cell_volume   189.25
_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
  Al  Al0  4  0.42  0.42  0.38  1.0
  Al  Al1  2  0.0  0.0  0.0  1.0
  I  I2  2  0.0  0.0  0.08  1.0

Al Al Al I
Al3I is Indium-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Al3I clusters. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted L-shaped geometry to one Al(1) and one I(1) atom. The Al(1)-Al(1) bond length is 0.96 Å. The Al(1)-I(1) bond length is 2.13 Å. In the second Al site, Al(2) is bonded in a single-bond geometry to one I(1) atom. The Al(2)-I(1) bond length is 0.48 Å. I(1) is bonded in a single-bond geometry to one Al(2) and two equivalent Al(1) atoms.