data_ZnAsPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.91
_cell_length_b   4.91
_cell_length_c   4.91
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ZnAsPb
_chemical_formula_sum   'Zn1 As1 Pb1'
_cell_volume   83.7
_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
  Zn  Zn2  1  0.0  0.0  0.0  1.0
  As  As0  1  0.47  0.47  0.47  1.0
  Pb  Pb1  1  0.74  0.74  0.74  1.0

data_ZnAsPb
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.91
_cell_length_b   4.91
_cell_length_c   12.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   ZnAsPb
_chemical_formula_sum   'Zn3 As3 Pb3'
_cell_volume   251.09
_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
  Zn  Zn0  3  0.0  0.0  0.0  1.0
  As  As1  3  0.0  0.0  0.53  1.0
  Pb  Pb2  3  0.0  0.0  0.26  1.0

Zn As Pb
Zn As Pb 0 2 - - - 0 2 - - o 0 2 - o - 0 2 o - - 0 1 - o o 0 1 o - o 0 1 o o - 1 2 - o o 1 2 o - o 1 2 o o - 1 2 o o o 
ZnAsPb is half-Heusler structured and crystallizes in the trigonal R3m space group. Zn(1) is bonded to four equivalent Pb(1) atoms to form ZnPb4 tetrahedra that share corners with four equivalent As(1)Pb4 tetrahedra, corners with twelve equivalent Zn(1)Pb4 tetrahedra, and edges with six equivalent As(1)Pb4 tetrahedra. There are three shorter (2.95 Å) and one longer (3.18 Å) Zn(1)-Pb(1) bond length. Pb(1) is bonded in a body-centered cubic geometry to four equivalent Zn(1) and four equivalent As(1) atoms. There are three shorter (2.95 Å) and one longer (3.18 Å) Pb(1)-As(1) bond length. As(1) is bonded to four equivalent Pb(1) atoms to form AsPb4 tetrahedra that share corners with four equivalent Zn(1)Pb4 tetrahedra, corners with twelve equivalent As(1)Pb4 tetrahedra, and edges with six equivalent Zn(1)Pb4 tetrahedra.