data_Ba2AlCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.66
_cell_length_b   5.66
_cell_length_c   5.66
_cell_angle_alpha   121.3
_cell_angle_beta   121.3
_cell_angle_gamma   87.77
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2AlCr
_chemical_formula_sum   'Ba2 Al1 Cr1'
_cell_volume   125.77
_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  0.78  0.0  0.04  1.0
  Ba  Ba2  1  0.0  0.78  0.04  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Cr  Cr3  1  0.0  0.0  0.08  1.0

data_Ba2AlCr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.85
_cell_length_b   7.85
_cell_length_c   5.66
_cell_angle_alpha   90.0
_cell_angle_beta   133.89
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2AlCr
_chemical_formula_sum   'Ba4 Al2 Cr2'
_cell_volume   251.54
_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  4  0.35  0.39  0.74  1.0
  Al  Al1  2  0.0  0.0  0.0  1.0
  Cr  Cr2  2  0.42  0.5  0.92  1.0

Ba Ba Al Cr
Ba2CrAl is Ammonia-derived structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ba2CrAl clusters. Ba(1) is bonded in a single-bond geometry to one Cr(1) atom. The Ba(1)-Cr(1) bond length is 1.17 Å. Cr(1) is bonded in a trigonal non-coplanar geometry to two equivalent Ba(1) and one Al(1) atom. The Cr(1)-Al(1) bond length is 0.46 Å. Al(1) is bonded in a single-bond geometry to one Cr(1) atom.