data_Ba2ZrAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.57
_cell_length_b   3.57
_cell_length_c   10.66
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2ZrAl
_chemical_formula_sum   'Ba2 Zr1 Al1'
_cell_volume   135.88
_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
  Ba  Ba1  1  0.79  0.79  0.46  1.0
  Ba  Ba2  1  0.79  0.79  0.2  1.0
  Zr  Zr3  1  0.0  0.0  0.33  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_Ba2ZrAl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   10.66
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2ZrAl
_chemical_formula_sum   'Ba4 Zr2 Al2'
_cell_volume   271.77
_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
  Ba  Ba0  2  0.29  0.5  0.2  1.0
  Ba  Ba1  2  0.29  0.5  0.46  1.0
  Zr  Zr2  2  0.0  0.0  0.33  1.0
  Al  Al3  2  0.0  0.0  0.0  1.0

Ba Ba Zr Al
Ba Ba Zr Al 0 2 + + o 1 2 + + o 1 3 + + o 
Ba2ZrAl crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ba2ZrAl clusters. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a single-bond geometry to one Zr(1) atom. The Ba(1)-Zr(1) bond length is 1.76 Å. In the second Ba site, Ba(2) is bonded in a distorted bent 120 degrees geometry to one Zr(1) and one Al(1) atom. The Ba(2)-Zr(1) bond length is 1.76 Å. The Ba(2)-Al(1) bond length is 2.40 Å. Zr(1) is bonded in a water-like geometry to one Ba(1) and one Ba(2) atom. Al(1) is bonded in a single-bond geometry to one Ba(2) atom.