data_Ba3Co
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.83
_cell_length_b   6.83
_cell_length_c   6.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba3Co
_chemical_formula_sum   'Ba6 Co2'
_cell_volume   318.24
_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
  Ba  Ba0  1  0.71  0.0  0.41  1.0
  Ba  Ba1  1  0.12  0.0  0.41  1.0
  Ba  Ba2  1  0.41  0.71  0.0  1.0
  Ba  Ba3  1  0.41  0.12  0.0  1.0
  Ba  Ba4  1  0.0  0.41  0.12  1.0
  Ba  Ba5  1  0.0  0.41  0.71  1.0
  Co  Co6  1  0.41  0.41  0.41  1.0
  Co  Co7  1  0.0  0.0  0.0  1.0

data_Ba3Co
_symmetry_space_group_name_H-M   R3
_cell_length_a   9.66
_cell_length_b   9.66
_cell_length_c   11.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Ba3Co
_chemical_formula_sum   'Ba18 Co6'
_cell_volume   954.73
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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  9  0.04  0.37  0.37  1.0
  Ba  Ba1  9  0.16  0.72  0.84  1.0
  Co  Co2  3  0.0  0.0  0.0  1.0
  Co  Co3  3  0.0  0.0  0.41  1.0

Ba Ba Ba Ba Ba Ba Co Co
Ba3Co crystallizes in the trigonal R3 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 3-coordinate geometry to one Ba(2), one Co(1), and one Co(2) atom. The Ba(1)-Ba(2) bond length is 2.82 Å. The Ba(1)-Co(1) bond length is 3.46 Å. The Ba(1)-Co(2) bond length is 3.46 Å. In the second Ba site, Ba(2) is bonded in a 1-coordinate geometry to one Ba(1), one Co(1), and two equivalent Co(2) atoms. The Ba(2)-Co(1) bond length is 3.46 Å. There is one shorter (2.94 Å) and one longer (4.09 Å) Ba(2)-Co(2) bond length. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted hexagonal planar geometry to three equivalent Ba(1) and three equivalent Ba(2) atoms. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to three equivalent Ba(1) and six equivalent Ba(2) atoms.