data_NaNb2Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.69
_cell_length_b   4.97
_cell_length_c   5.67
_cell_angle_alpha   90.0
_cell_angle_beta   100.62
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaNb2Al
_chemical_formula_sum   'Na1 Nb2 Al1'
_cell_volume   74.56
_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
  Na  Na1  1  0.0  0.0  0.0  1.0
  Nb  Nb2  1  0.76  0.49  0.48  1.0
  Nb  Nb3  1  0.89  0.49  0.08  1.0
  Al  Al0  1  0.82  0.0  0.78  1.0

data_NaNb2Al
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.69
_cell_length_b   4.97
_cell_length_c   5.67
_cell_angle_alpha   90.0
_cell_angle_beta   100.62
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaNb2Al
_chemical_formula_sum   'Na1 Nb2 Al1'
_cell_volume   74.56
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Nb  Nb1  1  0.76  0.49  0.48  1.0
  Nb  Nb2  1  0.89  0.49  0.08  1.0
  Al  Al3  1  0.82  0.0  0.78  1.0

Na Nb Nb Al
Na Nb Nb Al 0 3 - o - 0 2 - o o 0 2 - - o 1 2 - o o 1 2 o o o 1 1 + o o 1 3 o o o 1 3 o + o 2 3 o o - 2 2 + o o 
NaNb2Al crystallizes in the triclinic P1 space group. Na(1) is bonded in a single-bond geometry to two equivalent Nb(2) and one Al(1) atom. There is one shorter (2.50 Å) and one longer (2.62 Å) Na(1)-Nb(2) bond length. The Na(1)-Al(1) bond length is 1.23 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 5-coordinate geometry to one Nb(2), two equivalent Nb(1), and two equivalent Al(1) atoms. The Nb(1)-Nb(2) bond length is 2.35 Å. Both Nb(1)-Nb(1) bond lengths are 2.69 Å. There is one shorter (2.95 Å) and one longer (3.05 Å) Nb(1)-Al(1) bond length. In the second Nb site, Nb(2) is bonded in a 2-coordinate geometry to two equivalent Na(1) and one Nb(1) atom. Al(1) is bonded in a single-bond geometry to one Na(1) and two equivalent Nb(1) atoms.