data_Na2TaAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.57
_cell_length_b   6.57
_cell_length_c   6.57
_cell_angle_alpha   155.59
_cell_angle_beta   134.37
_cell_angle_gamma   52.42
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2TaAl
_chemical_formula_sum   'Na2 Ta1 Al1'
_cell_volume   83.3
_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  0.55  0.07  1.0
  Na  Na2  1  0.39  0.0  0.82  1.0
  Ta  Ta3  1  0.0  0.0  0.89  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_Na2TaAl
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.78
_cell_length_b   5.09
_cell_length_c   6.57
_cell_angle_alpha   112.81
_cell_angle_beta   102.21
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2TaAl
_chemical_formula_sum   'Na2 Ta1 Al1'
_cell_volume   83.3
_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  0.82  0.43  1.0
  Na  Na1  1  0.45  0.53  0.53  1.0
  Ta  Ta2  1  0.0  0.89  0.89  1.0
  Al  Al3  1  0.0  0.0  0.0  1.0

Na Na Ta Al
Na Na Ta Al 0 0 o + + 0 1 o o - 0 1 o + o 0 2 o o - 2 3 o o + 
Na2TaAl crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to two equivalent Na(2), two equivalent Ta(1), and one Al(1) atom. There is one shorter (2.15 Å) and one longer (2.46 Å) Na(1)-Na(2) bond length. There is one shorter (2.56 Å) and one longer (2.94 Å) Na(1)-Ta(1) bond length. The Na(1)-Al(1) bond length is 3.41 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent Na(1), two equivalent Na(2), one Ta(1), and one Al(1) atom. Both Na(2)-Na(2) bond lengths are 2.78 Å. The Na(2)-Ta(1) bond length is 2.90 Å. The Na(2)-Al(1) bond length is 3.30 Å. Ta(1) is bonded in a distorted single-bond geometry to one Na(2), two equivalent Na(1), and one Al(1) atom. The Ta(1)-Al(1) bond length is 0.71 Å. Al(1) is bonded in a single-bond geometry to one Na(1), one Na(2), and one Ta(1) atom.