data_Ba2AlNi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.02
_cell_length_b   4.02
_cell_length_c   8.21
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2AlNi
_chemical_formula_sum   'Ba2 Al1 Ni1'
_cell_volume   133.01
_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  0.01  0.01  0.23  1.0
  Ba  Ba2  1  0.01  0.01  0.98  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Ni  Ni3  1  0.0  0.0  0.11  1.0

data_Ba2AlNi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.69
_cell_length_b   5.69
_cell_length_c   8.21
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2AlNi
_chemical_formula_sum   'Ba4 Al2 Ni2'
_cell_volume   266.01
_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  0.01  0.0  0.23  1.0
  Ba  Ba1  2  0.01  0.0  0.98  1.0
  Al  Al2  2  0.0  0.0  0.0  1.0
  Ni  Ni3  2  0.0  0.0  0.11  1.0

Ba Ba Al Ni
Ba Ba Al Ni 0 3 o o o 1 2 o o + 1 3 o o + 2 3 o o o 
Ba2NiAl is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ba2NiAl clusters. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a single-bond geometry to one Ni(1) atom. The Ba(1)-Ni(1) bond length is 1.01 Å. In the second Ba site, Ba(2) is bonded in a single-bond geometry to one Al(1) atom. The Ba(2)-Al(1) bond length is 0.15 Å. Ni(1) is bonded in a linear geometry to one Ba(1) and one Al(1) atom. The Ni(1)-Al(1) bond length is 0.87 Å. Al(1) is bonded in a distorted bent 150 degrees geometry to one Ba(2) and one Ni(1) atom.