data_Be2Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.04
_cell_length_b   4.04
_cell_length_c   4.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Be2Al
_chemical_formula_sum   'Be4 Al2'
_cell_volume   68.53
_cell_formula_units_Z   2
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
  Be  Be2  1  0.0  0.0  0.0  1.0
  Be  Be3  1  0.0  0.0  0.42  1.0
  Be  Be4  1  0.02  0.17  0.63  1.0
  Be  Be5  1  0.0  0.34  0.21  1.0
  Al  Al0  1  0.02  0.17  0.21  1.0
  Al  Al1  1  0.0  0.34  0.63  1.0

data_Be2Al
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.04
_cell_length_b   4.04
_cell_length_c   4.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Be2Al
_chemical_formula_sum   'Be4 Al2'
_cell_volume   68.53
_cell_formula_units_Z   2
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
  Be  Be0  1  0.0  0.0  0.0  1.0
  Be  Be1  1  0.0  0.0  0.42  1.0
  Be  Be2  1  0.0  0.34  0.21  1.0
  Be  Be3  1  0.02  0.17  0.63  1.0
  Al  Al4  1  0.0  0.34  0.63  1.0
  Al  Al5  1  0.02  0.17  0.21  1.0

Be Be Be Be Al Al
Be2Al is Hg_xSn structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one Be2Al cluster. There are four inequivalent Be sites. In the first Be site, Be(1) is bonded in a distorted single-bond geometry to one Al(1) atom. The Be(1)-Al(1) bond length is 1.20 Å. In the second Be site, Be(2) is bonded in a bent 120 degrees geometry to one Be(3) and one Al(1) atom. The Be(2)-Be(3) bond length is 1.20 Å. The Be(2)-Al(1) bond length is 1.20 Å. In the third Be site, Be(3) is bonded in a 1-coordinate geometry to one Be(2) and one Al(2) atom. The Be(3)-Al(2) bond length is 0.73 Å. In the fourth Be site, Be(4) is bonded in a single-bond geometry to one Al(1) atom. The Be(4)-Al(1) bond length is 0.73 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a trigonal planar geometry to one Be(1), one Be(2), and one Be(4) atom. In the second Al site, Al(2) is bonded in a single-bond geometry to one Be(3) atom.