data_MgNbAl2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.52
_cell_length_b   9.52
_cell_length_c   9.52
_cell_angle_alpha   18.14
_cell_angle_beta   18.14
_cell_angle_gamma   18.14
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNbAl2
_chemical_formula_sum   'Mg1 Nb1 Al2'
_cell_volume   72.96
_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
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Nb  Nb3  1  0.0  0.0  0.04  1.0
  Al  Al0  1  0.0  0.0  0.14  1.0
  Al  Al1  1  0.0  0.0  0.93  1.0

data_MgNbAl2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.2
_cell_length_b   3.0
_cell_length_c   9.52
_cell_angle_alpha   90.0
_cell_angle_beta   100.49
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgNbAl2
_chemical_formula_sum   'Mg2 Nb2 Al4'
_cell_volume   145.93
_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
  Mg  Mg0  2  0.0  0.0  0.0  1.0
  Nb  Nb1  2  -0.0  0.0  0.96  1.0
  Al  Al2  2  -0.0  0.0  0.86  1.0
  Al  Al3  2  -0.0  0.0  0.07  1.0

Mg Nb Al Al
MgNbAl2 is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two MgNbAl2 clusters. Mg(1) is bonded in a linear geometry to one Nb(1) and one Al(2) atom. The Mg(1)-Nb(1) bond length is 0.34 Å. The Mg(1)-Al(2) bond length is 0.64 Å. Nb(1) is bonded in a distorted single-bond geometry to one Mg(1) and one Al(1) atom. The Nb(1)-Al(1) bond length is 0.98 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a single-bond geometry to one Nb(1) atom. In the second Al site, Al(2) is bonded in a single-bond geometry to one Mg(1) atom.