data_SiI3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.46
_cell_length_b   13.02
_cell_length_c   8.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiI3
_chemical_formula_sum   'Si8 I24'
_cell_volume   1576.89
_cell_formula_units_Z   8
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
  Si  Si24  1  0.12  0.77  0.43  1.0
  Si  Si25  1  0.96  0.26  0.85  1.0
  Si  Si26  1  0.73  0.26  0.33  1.0
  Si  Si27  1  0.35  0.77  0.76  1.0
  Si  Si28  1  0.11  0.26  0.61  1.0
  Si  Si29  1  0.73  0.77  0.04  1.0
  Si  Si30  1  0.5  0.77  0.52  1.0
  Si  Si31  1  0.34  0.26  0.95  1.0
  I  I0  1  0.46  0.75  0.89  1.0
  I  I1  1  0.46  0.79  0.89  1.0
  I  I2  1  0.7  0.26  0.94  1.0
  I  I3  1  0.07  0.77  0.78  1.0
  I  I4  1  0.06  0.23  0.91  1.0
  I  I5  1  0.06  0.28  0.91  1.0
  I  I6  1  0.29  0.23  0.28  1.0
  I  I7  1  0.29  0.28  0.28  1.0
  I  I8  1  0.3  0.77  0.4  1.0
  I  I9  1  0.93  0.26  0.25  1.0
  I  I10  1  0.69  0.75  0.3  1.0
  I  I11  1  0.69  0.79  0.3  1.0
  I  I12  1  0.77  0.24  0.08  1.0
  I  I13  1  0.77  0.27  0.08  1.0
  I  I14  1  0.53  0.77  0.13  1.0
  I  I15  1  0.16  0.26  0.97  1.0
  I  I16  1  0.17  0.74  0.1  1.0
  I  I17  1  0.17  0.8  0.1  1.0
  I  I18  1  0.4  0.74  0.46  1.0
  I  I19  1  0.4  0.8  0.46  1.0
  I  I20  1  0.39  0.26  0.59  1.0
  I  I21  1  0.76  0.77  0.43  1.0
  I  I22  1  0.0  0.24  0.48  1.0
  I  I23  1  0.0  0.27  0.48  1.0

data_SiI3
_symmetry_space_group_name_H-M   P-1
_cell_length_a   8.37
_cell_length_b   13.02
_cell_length_c   14.46
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   SiI3
_chemical_formula_sum   'Si8 I24'
_cell_volume   1576.89
_cell_formula_units_Z   8
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
  Si  Si0  2  0.07  0.26  0.62  1.0
  Si  Si1  2  0.17  0.74  0.23  1.0
  Si  Si2  2  0.26  0.74  0.61  1.0
  Si  Si3  2  0.35  0.26  0.0  1.0
  I  I4  2  0.1  0.26  0.34  1.0
  I  I5  2  0.2  0.24  0.73  1.0
  I  I6  2  0.2  0.27  0.73  1.0
  I  I7  2  0.22  0.72  0.33  1.0
  I  I8  2  0.22  0.77  0.33  1.0
  I  I9  2  0.25  0.74  0.97  1.0
  I  I10  2  0.28  0.74  0.43  1.0
  I  I11  2  0.39  0.73  0.04  1.0
  I  I12  2  0.39  0.76  0.04  1.0
  I  I13  2  0.41  0.23  0.44  1.0
  I  I14  2  0.41  0.28  0.44  1.0
  I  I15  2  0.44  0.26  0.8  1.0

Si Si Si Si Si Si Si Si I I I I I I I I I I I I I I I I I I I I I I I I
SiI3 is Indium-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four SiI2 clusters and four SiI4 clusters. In each SiI2 cluster, Si(2) is bonded in a 2-coordinate geometry to one I(5) and one I(6) atom. The Si(2)-I(5) bond length is 1.57 Å. The Si(2)-I(6) bond length is 1.57 Å. There are two inequivalent I sites. In the first I site, I(5) is bonded in a distorted single-bond geometry to one Si(2) and one I(6) atom. The I(5)-I(6) bond length is 0.72 Å. In the second I site, I(6) is bonded in a distorted single-bond geometry to one Si(2) and one I(5) atom. In each SiI4 cluster, Si(1) is bonded in a distorted rectangular see-saw-like geometry to one I(4), one I(7), one I(8), and one I(9) atom. The Si(1)-I(4) bond length is 3.10 Å. The Si(1)-I(7) bond length is 2.87 Å. The Si(1)-I(8) bond length is 2.87 Å. The Si(1)-I(9) bond length is 2.50 Å. There are four inequivalent I sites. In the first I site, I(4) is bonded in a single-bond geometry to one Si(1) atom. In the second I site, I(7) is bonded in a single-bond geometry to one Si(1) and one I(8) atom. The I(7)-I(8) bond length is 0.72 Å. In the third I site, I(8) is bonded in a single-bond geometry to one Si(1) and one I(7) atom. In the fourth I site, I(9) is bonded in a distorted single-bond geometry to one Si(1) atom.