data_Re3I
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.56
_cell_length_b   4.56
_cell_length_c   4.56
_cell_angle_alpha   120.8
_cell_angle_beta   120.8
_cell_angle_gamma   88.61
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Re3I
_chemical_formula_sum   'Re3 I1'
_cell_volume   66.26
_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
  Re  Re1  1  0.0  0.25  0.63  1.0
  Re  Re2  1  0.25  0.0  0.63  1.0
  Re  Re3  1  0.0  0.0  0.26  1.0
  I  I0  1  0.0  0.0  0.0  1.0

data_Re3I
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.37
_cell_length_b   6.37
_cell_length_c   4.56
_cell_angle_alpha   90.0
_cell_angle_beta   134.31
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Re3I
_chemical_formula_sum   'Re6 I2'
_cell_volume   132.51
_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
  Re  Re0  4  0.49  0.13  0.62  1.0
  Re  Re1  2  0.24  0.5  0.74  1.0
  I  I2  2  0.0  0.0  0.0  1.0

Re Re Re I
Re Re Re I 0 2 o o o 0 1 o o o 1 2 o o o 2 3 o o o 
Re3I crystallizes in the monoclinic Cm space group. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded in a 4-coordinate geometry to one Re(1), one Re(2), and two equivalent I(1) atoms. The Re(1)-Re(1) bond length is 1.61 Å. The Re(1)-Re(2) bond length is 1.47 Å. There is one shorter (2.48 Å) and one longer (2.93 Å) Re(1)-I(1) bond length. In the second Re site, Re(2) is bonded in a single-bond geometry to two equivalent Re(1) and one I(1) atom. The Re(2)-I(1) bond length is 1.20 Å. I(1) is bonded in a single-bond geometry to one Re(2) and four equivalent Re(1) atoms.