data_CuIr3I
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.84
_cell_length_b   4.84
_cell_length_c   4.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuIr3I
_chemical_formula_sum   'Cu1 Ir3 I1'
_cell_volume   113.3
_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
  Cu  Cu4  1  0.0  0.0  0.0  1.0
  Ir  Ir1  1  0.42  0.0  0.42  1.0
  Ir  Ir2  1  0.42  0.42  0.0  1.0
  Ir  Ir3  1  0.0  0.42  0.42  1.0
  I  I0  1  0.42  0.42  0.42  1.0

data_CuIr3I
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.84
_cell_length_b   6.84
_cell_length_c   8.38
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CuIr3I
_chemical_formula_sum   'Cu3 Ir9 I3'
_cell_volume   339.91
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Cu  Cu0  3  0.0  0.0  0.0  1.0
  Ir  Ir1  9  0.05  0.53  0.95  1.0
  I  I2  3  0.0  0.0  0.42  1.0

Cu Ir Ir Ir I
Ir3CuI crystallizes in the trigonal R3m space group. Ir(1) is bonded in a 1-coordinate geometry to one Cu(1) and two equivalent I(1) atoms. The Ir(1)-Cu(1) bond length is 2.87 Å. There is one shorter (2.03 Å) and one longer (2.81 Å) Ir(1)-I(1) bond length. Cu(1) is bonded in a 3-coordinate geometry to three equivalent Ir(1) atoms. I(1) is bonded to six equivalent Ir(1) atoms to form corner-sharing IIr6 octahedra. The corner-sharing octahedra are not tilted.