data_Si2IrBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.54
_cell_length_b   4.54
_cell_length_c   4.54
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2IrBr
_chemical_formula_sum   'Si2 Ir1 Br1'
_cell_volume   66.24
_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
  Si  Si2  1  0.0  0.0  0.0  1.0
  Si  Si3  1  0.82  0.82  0.82  1.0
  Ir  Ir1  1  0.61  0.61  0.61  1.0
  Br  Br0  1  0.21  0.21  0.21  1.0

data_Si2IrBr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.54
_cell_length_b   4.54
_cell_length_c   11.12
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Si2IrBr
_chemical_formula_sum   'Si6 Ir3 Br3'
_cell_volume   198.71
_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
  Si  Si0  3  0.0  0.0  0.0  1.0
  Si  Si1  3  0.0  0.0  0.18  1.0
  Ir  Ir2  3  0.0  0.0  0.39  1.0
  Br  Br3  3  0.0  0.0  0.79  1.0

Si Si Ir Br
IrSi2Br crystallizes in the trigonal R3m space group. Ir(1) is bonded in a 10-coordinate geometry to three equivalent Si(1), four equivalent Si(2), and three equivalent Br(1) atoms. All Ir(1)-Si(1) bond lengths are 2.71 Å. There is one shorter (2.35 Å) and three longer (2.95 Å) Ir(1)-Si(2) bond lengths. All Ir(1)-Br(1) bond lengths are 2.71 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 1-coordinate geometry to three equivalent Ir(1), one Si(2), and one Br(1) atom. The Si(1)-Si(2) bond length is 2.03 Å. The Si(1)-Br(1) bond length is 2.35 Å. In the second Si site, Si(2) is bonded in a 5-coordinate geometry to four equivalent Ir(1), one Si(1), and three equivalent Br(1) atoms. All Si(2)-Br(1) bond lengths are 2.71 Å. Br(1) is bonded in a 7-coordinate geometry to three equivalent Ir(1), one Si(1), and three equivalent Si(2) atoms.