data_HgPbBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.36
_cell_length_b   5.36
_cell_length_c   5.36
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgPbBr
_chemical_formula_sum   'Hg1 Pb1 Br1'
_cell_volume   108.81
_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
  Hg  Hg1  1  0.68  0.68  0.68  1.0
  Pb  Pb2  1  0.89  0.89  0.89  1.0
  Br  Br0  1  0.0  0.0  0.0  1.0

data_HgPbBr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.36
_cell_length_b   5.36
_cell_length_c   13.13
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   HgPbBr
_chemical_formula_sum   'Hg3 Pb3 Br3'
_cell_volume   326.42
_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
  Hg  Hg0  3  0.0  0.0  0.32  1.0
  Pb  Pb1  3  0.0  0.0  0.11  1.0
  Br  Br2  3  0.0  0.0  0.0  1.0

Hg Pb Br
Hg Pb Br 0 1 o - o 0 1 - o o 0 1 o o - 0 1 o o o 0 2 o + + 0 2 + o + 0 2 + + o 1 2 + + + 
HgPbBr crystallizes in the trigonal R3m space group. Hg(1) is bonded to one Pb(1) and three equivalent Br(1) atoms to form corner-sharing HgPbBr3 trigonal pyramids. The Hg(1)-Pb(1) bond length is 2.77 Å. All Hg(1)-Br(1) bond lengths are 3.10 Å. Pb(1) is bonded in a distorted single-bond geometry to one Hg(1) and one Br(1) atom. The Pb(1)-Br(1) bond length is 1.38 Å. Br(1) is bonded in a single-bond geometry to three equivalent Hg(1) and one Pb(1) atom.