data_MgTaPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.81
_cell_length_b   4.81
_cell_length_c   4.81
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgTaPb
_chemical_formula_sum   'Mg1 Ta1 Pb1'
_cell_volume   78.66
_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
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Ta  Ta2  1  0.7  0.7  0.7  1.0
  Pb  Pb1  1  0.4  0.4  0.4  1.0

data_MgTaPb
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.81
_cell_length_b   4.81
_cell_length_c   11.78
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgTaPb
_chemical_formula_sum   'Mg3 Ta3 Pb3'
_cell_volume   235.97
_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
  Mg  Mg0  3  0.0  0.0  0.0  1.0
  Ta  Ta1  3  0.0  0.0  0.3  1.0
  Pb  Pb2  3  0.0  0.0  0.6  1.0

Mg Ta Pb
MgTaPb is half-Heusler structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded to four equivalent Ta(1) and three equivalent Pb(1) atoms to form distorted MgTa4Pb3 hexagonal pyramids that share corners with six equivalent Ta(1)Mg4Pb4 hexagonal bipyramids, corners with four equivalent Pb(1)Mg3Ta4 hexagonal pyramids, corners with six equivalent Mg(1)Ta4Pb3 hexagonal pyramids, edges with three equivalent Ta(1)Mg4Pb4 hexagonal bipyramids, edges with six equivalent Mg(1)Ta4Pb3 hexagonal pyramids, and edges with six equivalent Pb(1)Mg3Ta4 hexagonal pyramids. There are three shorter (2.80 Å) and one longer (3.53 Å) Mg(1)-Ta(1) bond length. All Mg(1)-Pb(1) bond lengths are 2.89 Å. Ta(1) is bonded to four equivalent Mg(1) and four equivalent Pb(1) atoms to form distorted TaMg4Pb4 hexagonal bipyramids that share corners with six equivalent Mg(1)Ta4Pb3 hexagonal pyramids, corners with six equivalent Pb(1)Mg3Ta4 hexagonal pyramids, edges with twelve equivalent Ta(1)Mg4Pb4 hexagonal bipyramids, edges with three equivalent Mg(1)Ta4Pb3 hexagonal pyramids, and edges with three equivalent Pb(1)Mg3Ta4 hexagonal pyramids. There are three shorter (2.80 Å) and one longer (3.53 Å) Ta(1)-Pb(1) bond length. Pb(1) is bonded to three equivalent Mg(1) and four equivalent Ta(1) atoms to form distorted PbMg3Ta4 hexagonal pyramids that share corners with six equivalent Ta(1)Mg4Pb4 hexagonal bipyramids, corners with four equivalent Mg(1)Ta4Pb3 hexagonal pyramids, corners with six equivalent Pb(1)Mg3Ta4 hexagonal pyramids, edges with three equivalent Ta(1)Mg4Pb4 hexagonal bipyramids, edges with six equivalent Mg(1)Ta4Pb3 hexagonal pyramids, and edges with six equivalent Pb(1)Mg3Ta4 hexagonal pyramids.