data_Si2GeBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.15
_cell_length_b   4.93
_cell_length_c   5.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2GeBr
_chemical_formula_sum   'Si2 Ge1 Br1'
_cell_volume   78.12
_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  0.58  0.46  0.0  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Ge  Ge1  1  0.58  0.0  0.52  1.0
  Br  Br0  1  0.0  0.46  0.52  1.0

data_Si2GeBr
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.15
_cell_length_b   4.93
_cell_length_c   5.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2GeBr
_chemical_formula_sum   'Si2 Ge1 Br1'
_cell_volume   78.12
_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  Si0  1  0.0  0.0  0.0  1.0
  Si  Si1  1  0.58  0.46  0.0  1.0
  Ge  Ge2  1  0.58  0.0  0.52  1.0
  Br  Br3  1  0.0  0.46  0.52  1.0

Si Si Ge Br
Si Si Ge Br 0 1 o o o 0 1 o + o 0 1 + o o 0 1 + + o 0 3 o o - 0 3 o o o 0 3 + o - 0 3 + o o 0 0 + o o 0 2 o o - 0 2 o o o 1 2 - o - 1 2 - o o 1 2 o o - 1 2 o o o 1 1 + o o 1 3 o o - 1 3 o o o 2 3 o - o 2 3 o o o 2 3 + - o 2 3 + o o 2 2 + o o 3 3 + o o 
GeSi2Br crystallizes in the triclinic P1 space group. Ge(1) is bonded in a 5-coordinate geometry to two equivalent Si(2) and three equivalent Br(1) atoms. There is one shorter (2.78 Å) and one longer (2.92 Å) Ge(1)-Si(2) bond length. There are a spread of Ge(1)-Br(1) bond distances ranging from 2.64-2.96 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 2-coordinate geometry to one Si(2) and two equivalent Br(1) atoms. The Si(1)-Si(2) bond length is 2.64 Å. There is one shorter (2.78 Å) and one longer (2.92 Å) Si(1)-Br(1) bond length. In the second Si site, Si(2) is bonded in a 3-coordinate geometry to two equivalent Ge(1) and one Si(1) atom. Br(1) is bonded in a 5-coordinate geometry to three equivalent Ge(1) and two equivalent Si(1) atoms.