data_Ca3Co
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.53
_cell_length_b   3.53
_cell_length_c   9.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Co
_chemical_formula_sum   'Ca3 Co1'
_cell_volume   119.26
_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
  Ca  Ca0  1  0.76  0.76  0.44  1.0
  Ca  Ca1  1  0.0  0.0  0.0  1.0
  Ca  Ca2  1  0.76  0.76  0.15  1.0
  Co  Co3  1  0.0  0.0  0.79  1.0

data_Ca3Co
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.99
_cell_length_b   4.99
_cell_length_c   9.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ca3Co
_chemical_formula_sum   'Ca6 Co2'
_cell_volume   238.51
_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
  Ca  Ca0  2  0.0  0.0  0.0  1.0
  Ca  Ca1  2  0.26  0.5  0.15  1.0
  Ca  Ca2  2  0.26  0.5  0.44  1.0
  Co  Co3  2  0.0  0.0  0.79  1.0

Ca Ca Ca Co
Ca Ca Ca Co 0 0 + o o 0 0 o + o 0 2 o o o 0 3 + + o 1 2 - - o 1 3 o o - 
Ca3Co crystallizes in the monoclinic Cm space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one Ca(3), four equivalent Ca(1), and one Co(1) atom to form a mixture of distorted edge and corner-sharing CaCa5Co octahedra. The corner-sharing octahedra are not tilted. The Ca(1)-Ca(3) bond length is 2.78 Å. All Ca(1)-Ca(1) bond lengths are 3.53 Å. The Ca(1)-Co(1) bond length is 3.60 Å. In the second Ca site, Ca(2) is bonded in a distorted single-bond geometry to one Ca(3) and one Co(1) atom. The Ca(2)-Ca(3) bond length is 1.86 Å. The Ca(2)-Co(1) bond length is 1.97 Å. In the third Ca site, Ca(3) is bonded in a 1-coordinate geometry to one Ca(1) and one Ca(2) atom. Co(1) is bonded in a single-bond geometry to one Ca(1) and one Ca(2) atom.