data_GeAsPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.92
_cell_length_b   4.92
_cell_length_c   4.92
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   GeAsPb
_chemical_formula_sum   'Ge1 As1 Pb1'
_cell_volume   84.45
_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
  Ge  Ge1  1  0.0  0.0  0.0  1.0
  As  As0  1  0.48  0.48  0.48  1.0
  Pb  Pb2  1  0.74  0.74  0.74  1.0

data_GeAsPb
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.92
_cell_length_b   4.92
_cell_length_c   12.06
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   GeAsPb
_chemical_formula_sum   'Ge3 As3 Pb3'
_cell_volume   253.34
_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
  Ge  Ge0  3  0.0  0.0  0.0  1.0
  As  As1  3  0.0  0.0  0.52  1.0
  Pb  Pb2  3  0.0  0.0  0.26  1.0

Ge As Pb
Ge As Pb 0 1 - - o 0 1 - o - 0 1 - o o 0 1 o - - 0 1 o - o 0 1 o o - 0 2 - - - 0 2 - - o 0 2 - o - 0 2 o - - 1 2 - o o 1 2 o - o 1 2 o o - 1 2 o o o 
PbGeAs is half-Heusler structured and crystallizes in the trigonal R3m space group. Pb(1) is bonded in a body-centered cubic geometry to four equivalent Ge(1) and four equivalent As(1) atoms. There are three shorter (2.98 Å) and one longer (3.12 Å) Pb(1)-Ge(1) bond length. There are three shorter (2.98 Å) and one longer (3.12 Å) Pb(1)-As(1) bond length. Ge(1) is bonded to four equivalent Pb(1) atoms to form GePb4 tetrahedra that share corners with four equivalent As(1)Pb4 tetrahedra, corners with twelve equivalent Ge(1)Pb4 tetrahedra, and edges with six equivalent As(1)Pb4 tetrahedra. As(1) is bonded to four equivalent Pb(1) atoms to form AsPb4 tetrahedra that share corners with four equivalent Ge(1)Pb4 tetrahedra, corners with twelve equivalent As(1)Pb4 tetrahedra, and edges with six equivalent Ge(1)Pb4 tetrahedra.