The structure described by Ca2Co3O8 crystallizes in the monoclinic C2/m space group. Ca(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form distorted CaO6 pentagonal pyramids that share corners with three equivalent Co(1)O6 octahedra, corners with four equivalent Co(2)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 21-55°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Ca(1)O6 pentagonal pyramids, edges with four equivalent Co(2)O6 octahedra, and edges with two equivalent Ca(1)O6 pentagonal pyramids. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with four equivalent Ca(1)O6 pentagonal pyramids, edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Ca(1)O6 pentagonal pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1) and two equivalent Co(2) atoms. In the second O site, O(2) is bonded to one Ca(1), one Co(1), and two equivalent Co(2) atoms to form distorted OCaCo3 trigonal pyramids that share  a cornercorner with one O(2)CaCo3 trigonal pyramid, corners with four equivalent O(3)Ca2Co2 trigonal pyramids,  an edgeedge with one O(2)CaCo3 trigonal pyramid, and edges with four equivalent O(3)Ca2Co2 trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Ca(1), one Co(1), and one Co(2) atom to form distorted OCa2Co2 trigonal pyramids that share corners with two equivalent O(2)CaCo3 trigonal pyramids, corners with six equivalent O(3)Ca2Co2 trigonal pyramids, edges with two equivalent O(3)Ca2Co2 trigonal pyramids, and edges with two equivalent O(2)CaCo3 trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Co3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.161
_cell_length_b   6.161
_cell_length_c   4.894
_cell_angle_alpha   72.939
_cell_angle_beta   72.939
_cell_angle_gamma   55.331
_symmetry_Int_Tables_number   1
_cell_volume   144.123
_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  0.727  0.727  0.326  1.0
  Ca  Ca1  1  0.273  0.273  0.674  1.0
  Co  Co2  1  0.000  0.000  0.500  1.0
  Co  Co3  1  0.743  0.257  0.000  1.0
  Co  Co4  1  0.257  0.743  0.000  1.0
  O  O5  1  0.400  0.400  0.961  1.0
  O  O6  1  0.600  0.600  0.039  1.0
  O  O7  1  0.905  0.905  0.903  1.0
  O  O8  1  0.095  0.095  0.097  1.0
  O  O9  1  0.320  0.875  0.609  1.0
  O  O10  1  0.875  0.320  0.609  1.0
  O  O11  1  0.125  0.680  0.391  1.0
  O  O12  1  0.680  0.125  0.391  1.0
[/CIF]
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The structure described by Ca2Co3O8 crystallizes in the monoclinic C2/m space group. Ca(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form distorted CaO6 pentagonal pyramids that share corners with three equivalent Co(1)O6 octahedra, corners with four equivalent Co(2)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 21-55°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Ca(1)O6 pentagonal pyramids, edges with four equivalent Co(2)O6 octahedra, and edges with two equivalent Ca(1)O6 pentagonal pyramids. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with four equivalent Ca(1)O6 pentagonal pyramids, edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Ca(1)O6 pentagonal pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1) and two equivalent Co(2) atoms. In the second O site, O(2) is bonded to one Ca(1), one Co(1), and two equivalent Co(2) atoms to form distorted OCaCo3 trigonal pyramids that share  a cornercorner with one O(2)CaCo3 trigonal pyramid, corners with four equivalent O(3)Ca2Co2 trigonal pyramids,  an edgeedge with one O(2)CaCo3 trigonal pyramid, and edges with four equivalent O(3)Ca2Co2 trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Ca(1), one Co(1), and one Co(2) atom to form distorted OCa2Co2 trigonal pyramids that share corners with two equivalent O(2)CaCo3 trigonal pyramids, corners with six equivalent O(3)Ca2Co2 trigonal pyramids, edges with two equivalent O(3)Ca2Co2 trigonal pyramids, and edges with two equivalent O(2)CaCo3 trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Co3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.161
_cell_length_b   6.161
_cell_length_c   4.894
_cell_angle_alpha   72.939
_cell_angle_beta   72.939
_cell_angle_gamma   55.331
_symmetry_Int_Tables_number   1
_cell_volume   144.123
_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  0.727  0.727  0.326  1.0
  Ca  Ca1  1  0.273  0.273  0.674  1.0
  Co  Co2  1  0.000  0.000  0.500  1.0
  Co  Co3  1  0.743  0.257  0.000  1.0
  Co  Co4  1  0.257  0.743  0.000  1.0
  O  O5  1  0.400  0.400  0.961  1.0
  O  O6  1  0.600  0.600  0.039  1.0
  O  O7  1  0.905  0.905  0.903  1.0
  O  O8  1  0.095  0.095  0.097  1.0
  O  O9  1  0.320  0.875  0.609  1.0
  O  O10  1  0.875  0.320  0.609  1.0
  O  O11  1  0.125  0.680  0.391  1.0
  O  O12  1  0.680  0.125  0.391  1.0
[/CIF]
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