data_SmNbAl2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.88
_cell_length_b   4.88
_cell_length_c   4.88
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SmNbAl2
_chemical_formula_sum   'Sm1 Nb1 Al2'
_cell_volume   82.12
_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
  Sm  Sm3  1  0.45  0.45  0.45  1.0
  Nb  Nb2  1  0.0  0.0  0.0  1.0
  Al  Al0  1  0.17  0.17  0.17  1.0
  Al  Al1  1  0.72  0.72  0.72  1.0

data_SmNbAl2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.88
_cell_length_b   4.88
_cell_length_c   11.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SmNbAl2
_chemical_formula_sum   'Sm3 Nb3 Al6'
_cell_volume   246.36
_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
  Sm  Sm0  3  0.0  0.0  0.55  1.0
  Nb  Nb1  3  0.0  0.0  -0.0  1.0
  Al  Al2  3  0.0  0.0  0.28  1.0
  Al  Al3  3  0.0  0.0  0.83  1.0

Sm Nb Al Al
SmNbAl2 is Heusler structured and crystallizes in the trigonal R3m space group. Sm(1) is bonded in a 11-coordinate geometry to three equivalent Nb(1), four equivalent Al(1), and four equivalent Al(2) atoms. All Sm(1)-Nb(1) bond lengths are 3.14 Å. There are three shorter (2.90 Å) and one longer (3.29 Å) Sm(1)-Al(1) bond length. There are three shorter (2.90 Å) and one longer (3.29 Å) Sm(1)-Al(2) bond length. Nb(1) is bonded in a distorted single-bond geometry to three equivalent Sm(1), one Al(1), and four equivalent Al(2) atoms. The Nb(1)-Al(1) bond length is 2.09 Å. There are three shorter (2.90 Å) and one longer (3.29 Å) Nb(1)-Al(2) bond length. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 5-coordinate geometry to four equivalent Sm(1) and one Nb(1) atom. In the second Al site, Al(2) is bonded in a 8-coordinate geometry to four equivalent Sm(1) and four equivalent Nb(1) atoms.