data_SrHfAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   5.05
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrHfAl
_chemical_formula_sum   'Sr1 Hf1 Al1'
_cell_volume   91.27
_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
  Sr  Sr2  1  0.57  0.57  0.57  1.0
  Hf  Hf1  1  0.36  0.36  0.36  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_SrHfAl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   12.38
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrHfAl
_chemical_formula_sum   'Sr3 Hf3 Al3'
_cell_volume   273.8
_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
  Sr  Sr0  3  0.0  0.0  0.43  1.0
  Hf  Hf1  3  0.0  0.0  0.64  1.0
  Al  Al2  3  0.0  0.0  -0.0  1.0

Sr Hf Al
Sr Hf Al 0 1 o o o 0 1 o o + 0 1 + o o 0 1 o + o 0 2 o + + 0 2 + o + 0 2 + + o 1 2 o o + 1 2 o + o 1 2 + o o 
SrHfAl is half-Heusler structured and crystallizes in the trigonal R3m space group. Sr(1) is bonded in a 7-coordinate geometry to four equivalent Hf(1) and three equivalent Al(1) atoms. There is one shorter (2.64 Å) and three longer (3.27 Å) Sr(1)-Hf(1) bond lengths. All Sr(1)-Al(1) bond lengths are 3.14 Å. Hf(1) is bonded in a 7-coordinate geometry to four equivalent Sr(1) and three equivalent Al(1) atoms. All Hf(1)-Al(1) bond lengths are 2.94 Å. Al(1) is bonded in a hexagonal planar geometry to three equivalent Sr(1) and three equivalent Hf(1) atoms.