data_YNb3Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.86
_cell_length_b   4.86
_cell_length_c   4.86
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YNb3Al
_chemical_formula_sum   'Y1 Nb3 Al1'
_cell_volume   114.95
_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
  Y  Y0  1  0.43  0.43  0.43  1.0
  Nb  Nb1  1  0.0  0.43  0.0  1.0
  Nb  Nb2  1  0.0  0.0  0.43  1.0
  Nb  Nb3  1  0.43  0.0  0.0  1.0
  Al  Al4  1  0.0  0.0  0.0  1.0

data_YNb3Al
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.88
_cell_length_b   6.88
_cell_length_c   8.42
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   YNb3Al
_chemical_formula_sum   'Y3 Nb9 Al3'
_cell_volume   344.86
_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
  Y  Y0  3  0.0  0.0  0.43  1.0
  Nb  Nb1  9  0.19  0.38  0.81  1.0
  Al  Al2  3  0.0  0.0  0.0  1.0

Y Nb Nb Nb Al
YNb3Al is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Y(1) is bonded to twelve equivalent Nb(1) atoms to form distorted YNb12 cuboctahedra that share corners with twelve equivalent Y(1)Nb12 cuboctahedra, faces with six equivalent Y(1)Nb12 cuboctahedra, and faces with eight equivalent Al(1)Nb6 octahedra. There are a spread of Y(1)-Nb(1) bond distances ranging from 2.96-3.91 Å. Nb(1) is bonded in a 5-coordinate geometry to four equivalent Y(1) and two equivalent Al(1) atoms. There is one shorter (2.10 Å) and one longer (2.77 Å) Nb(1)-Al(1) bond length. Al(1) is bonded to six equivalent Nb(1) atoms to form AlNb6 octahedra that share corners with six equivalent Al(1)Nb6 octahedra and faces with eight equivalent Y(1)Nb12 cuboctahedra. The corner-sharing octahedra are not tilted.