data_In2SiBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   5.2
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   In2SiBr
_chemical_formula_sum   'In2 Si1 Br1'
_cell_volume   99.55
_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
  In  In1  1  0.52  0.52  0.52  1.0
  In  In2  1  0.68  0.68  0.68  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Br  Br0  1  0.84  0.84  0.84  1.0

data_In2SiBr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   12.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   In2SiBr
_chemical_formula_sum   'In6 Si3 Br3'
_cell_volume   298.66
_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
  In  In0  3  0.0  0.0  0.32  1.0
  In  In1  3  0.0  0.0  0.48  1.0
  Si  Si2  3  0.0  0.0  0.0  1.0
  Br  Br3  3  0.0  0.0  0.16  1.0

In In Si Br
In In Si Br 0 1 o o o 1 3 o o o 2 3 - - - 
In2SiBr crystallizes in the trigonal R3m space group. There are two inequivalent In sites. In the first In site, In(1) is bonded to one In(2) and three equivalent Br(1) atoms to form InInBr3 trigonal pyramids that share  a cornercorner with one Br(1)In4Si trigonal bipyramid and corners with six equivalent In(1)InBr3 trigonal pyramids. The In(1)-In(2) bond length is 2.05 Å. All In(1)-Br(1) bond lengths are 3.01 Å. In the second In site, In(2) is bonded in a single-bond geometry to one In(1) and one Br(1) atom. The In(2)-Br(1) bond length is 2.05 Å. Si(1) is bonded in a single-bond geometry to one Br(1) atom. The Si(1)-Br(1) bond length is 2.05 Å. Br(1) is bonded to one In(2), three equivalent In(1), and one Si(1) atom to form distorted BrIn4Si trigonal bipyramids that share corners with six equivalent Br(1)In4Si trigonal bipyramids and  a cornercorner with one In(1)InBr3 trigonal pyramid.