data_Na2YAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.02
_cell_length_b   12.02
_cell_length_c   12.02
_cell_angle_alpha   15.89
_cell_angle_beta   15.89
_cell_angle_gamma   15.89
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2YAl
_chemical_formula_sum   'Na2 Y1 Al1'
_cell_volume   113.41
_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  0.15  1.0
  Na  Na2  1  0.0  0.0  0.45  1.0
  Y  Y3  1  0.0  0.0  0.8  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_Na2YAl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.75
_cell_length_b   3.32
_cell_length_c   12.02
_cell_angle_alpha   90.0
_cell_angle_beta   99.18
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2YAl
_chemical_formula_sum   'Na4 Y2 Al2'
_cell_volume   226.82
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.55  1.0
  Na  Na1  2  0.0  0.0  0.85  1.0
  Y  Y2  2  0.0  0.0  0.2  1.0
  Al  Al3  2  0.0  0.0  0.0  1.0

Na Na Y Al
Na2YAl crystallizes in the monoclinic Cm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a single-bond geometry to one Na(2) and one Al(1) atom. The Na(1)-Na(2) bond length is 3.63 Å. The Na(1)-Al(1) bond length is 1.77 Å. In the second Na site, Na(2) is bonded to one Na(1), six equivalent Na(2), and one Y(1) atom to form a mixture of corner and edge-sharing NaNa7Y hexagonal bipyramids. All Na(2)-Na(2) bond lengths are 3.32 Å. The Na(2)-Y(1) bond length is 4.20 Å. Y(1) is bonded in a single-bond geometry to one Na(2) and one Al(1) atom. The Y(1)-Al(1) bond length is 2.42 Å. Al(1) is bonded in a distorted linear geometry to one Na(1) and one Y(1) atom.