data_SiPbBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.93
_cell_length_b   4.93
_cell_length_c   4.93
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiPbBr
_chemical_formula_sum   'Si1 Pb1 Br1'
_cell_volume   84.51
_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
  Pb  Pb1  1  0.74  0.74  0.74  1.0
  Br  Br0  1  0.22  0.22  0.22  1.0

data_SiPbBr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.93
_cell_length_b   4.93
_cell_length_c   12.07
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SiPbBr
_chemical_formula_sum   'Si3 Pb3 Br3'
_cell_volume   253.53
_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
  Pb  Pb1  3  0.0  0.0  0.26  1.0
  Br  Br2  3  0.0  0.0  0.78  1.0

Si Pb Br
Si Pb Br 0 2 o - o 0 2 - o o 0 2 o o - 0 2 o o o 0 1 - - - 0 1 - - o 0 1 - o - 0 1 o - - 1 2 o o + 1 2 o + o 1 2 o + + 1 2 + o o 1 2 + o + 1 2 + + o 
PbSiBr is half-Heusler structured and crystallizes in the trigonal R3m space group. Pb(1) is bonded to four equivalent Si(1) and three equivalent Br(1) atoms to form a mixture of distorted edge and corner-sharing PbSi4Br3 tetrahedra. There are three shorter (2.98 Å) and one longer (3.12 Å) Pb(1)-Si(1) bond length. All Pb(1)-Br(1) bond lengths are 3.37 Å. Si(1) is bonded in a 5-coordinate geometry to four equivalent Pb(1) and one Br(1) atom. The Si(1)-Br(1) bond length is 2.71 Å. Br(1) is bonded in a single-bond geometry to three equivalent Pb(1) and one Si(1) atom.