data_BaAl2Co
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.93
_cell_length_b   4.93
_cell_length_c   4.93
_cell_angle_alpha   118.7
_cell_angle_beta   118.7
_cell_angle_gamma   92.27
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaAl2Co
_chemical_formula_sum   'Ba1 Al2 Co1'
_cell_volume   86.55
_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  Ba2  1  0.0  0.0  0.42  1.0
  Al  Al0  1  0.52  0.0  0.71  1.0
  Al  Al1  1  0.0  0.52  0.71  1.0
  Co  Co3  1  0.0  0.0  0.0  1.0

data_BaAl2Co
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.84
_cell_length_b   7.12
_cell_length_c   4.93
_cell_angle_alpha   90.0
_cell_angle_beta   133.86
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BaAl2Co
_chemical_formula_sum   'Ba2 Al4 Co2'
_cell_volume   173.11
_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  0.0  0.0  0.58  1.0
  Al  Al1  4  0.24  0.24  0.29  1.0
  Co  Co2  2  0.0  0.0  0.0  1.0

Ba Al Al Co
Ba Al Al Co 0 2 o o o 0 3 o o o 0 1 o o o 1 3 + o + 2 3 o + + 
BaCoAl2 crystallizes in the monoclinic Cm space group. Ba(1) is bonded in a 3-coordinate geometry to two equivalent Co(1) and two equivalent Al(1) atoms. There is one shorter (2.07 Å) and one longer (2.87 Å) Ba(1)-Co(1) bond length. Both Ba(1)-Al(1) bond lengths are 2.24 Å. Co(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Al(1) atoms. Both Co(1)-Al(1) bond lengths are 2.12 Å. Al(1) is bonded in a linear geometry to one Ba(1) and one Co(1) atom.