data_HfMg3Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   4.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfMg3Au
_chemical_formula_sum   'Hf1 Mg3 Au1'
_cell_volume   122.54
_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
  Hf  Hf0  1  0.0  0.0  0.0  1.0
  Mg  Mg1  1  0.48  0.0  0.48  1.0
  Mg  Mg2  1  0.48  0.48  0.0  1.0
  Mg  Mg3  1  0.0  0.48  0.48  1.0
  Au  Au4  1  0.48  0.48  0.48  1.0

data_HfMg3Au
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.02
_cell_length_b   7.02
_cell_length_c   8.6
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   HfMg3Au
_chemical_formula_sum   'Hf3 Mg9 Au3'
_cell_volume   367.62
_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
  Hf  Hf0  3  0.0  0.0  0.0  1.0
  Mg  Mg1  9  0.01  0.51  0.99  1.0
  Au  Au2  3  0.0  0.0  0.48  1.0

Hf Mg Mg Mg Au
Hf Mg Mg Mg Au 0 2 - - o 0 2 - o o 0 2 o - o 0 2 o o o 0 1 - o - 0 1 - o o 0 1 o o - 0 1 o o o 0 3 o - - 0 3 o - o 0 3 o o - 0 3 o o o 0 4 o o o 1 4 o - o 1 4 o o o 2 4 o o - 2 4 o o o 3 4 - o o 3 4 o o o 
Mg3HfAu is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded in a linear geometry to four equivalent Hf(1) and two equivalent Au(1) atoms. There are a spread of Mg(1)-Hf(1) bond distances ranging from 3.40-3.63 Å. There is one shorter (2.40 Å) and one longer (2.57 Å) Mg(1)-Au(1) bond length. Hf(1) is bonded to twelve equivalent Mg(1) atoms to form HfMg12 cuboctahedra that share corners with twelve equivalent Hf(1)Mg12 cuboctahedra, faces with six equivalent Hf(1)Mg12 cuboctahedra, and faces with eight equivalent Au(1)Mg6 octahedra. Au(1) is bonded to six equivalent Mg(1) atoms to form AuMg6 octahedra that share corners with six equivalent Au(1)Mg6 octahedra and faces with eight equivalent Hf(1)Mg12 cuboctahedra. The corner-sharing octahedra are not tilted.