data_BaCoSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.24
_cell_length_b   3.24
_cell_length_c   7.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaCoSi2
_chemical_formula_sum   'Ba1 Co1 Si2'
_cell_volume   77.62
_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  Ba0  1  0.62  0.62  0.73  1.0
  Co  Co1  1  0.0  0.0  0.39  1.0
  Si  Si2  1  0.62  0.62  0.14  1.0
  Si  Si3  1  0.0  0.0  0.24  1.0

data_BaCoSi2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.58
_cell_length_b   4.58
_cell_length_c   7.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BaCoSi2
_chemical_formula_sum   'Ba2 Co2 Si4'
_cell_volume   155.24
_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  0.12  0.5  0.73  1.0
  Co  Co1  2  0.0  0.0  0.39  1.0
  Si  Si2  2  0.0  0.0  0.24  1.0
  Si  Si3  2  0.12  0.5  0.14  1.0

Ba Co Si Si
BaCoSi2 crystallizes in the monoclinic Cm space group. Ba(1) is bonded in a 9-coordinate geometry to four equivalent Ba(1), four equivalent Co(1), and one Si(1) atom. All Ba(1)-Ba(1) bond lengths are 3.24 Å. There are a spread of Ba(1)-Co(1) bond distances ranging from 3.03-3.77 Å. The Ba(1)-Si(1) bond length is 3.04 Å. Co(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one Si(2) atom. The Co(1)-Si(2) bond length is 1.16 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to one Ba(1) and three equivalent Si(2) atoms. There is one shorter (1.89 Å) and two longer (2.47 Å) Si(1)-Si(2) bond lengths. In the second Si site, Si(2) is bonded in a distorted single-bond geometry to one Co(1) and three equivalent Si(1) atoms.