The material described by CaCo2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(3) and three equivalent O(4) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-73°. In the second Ca site, Ca(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form distorted CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Co(1)O4 tetrahedra, and edges with six equivalent Co(2)O6 octahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2) and three equivalent O(1) atoms to form CoO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-63°. In the second Co site, Co(2) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Co(1)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(2), one Co(1), and two equivalent Co(2) atoms to form distorted OCaCo3 trigonal pyramids that share corners with two equivalent O(1)CaCo3 trigonal pyramids, corners with two equivalent O(3)CaCo3 trigonal pyramids, corners with seven equivalent O(4)Ca2Co2 trigonal pyramids, and edges with two equivalent O(1)CaCo3 trigonal pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Co(1) and three equivalent Co(2) atoms. In the third O site, O(3) is bonded to one Ca(1) and three equivalent Co(2) atoms to form distorted OCaCo3 trigonal pyramids that share corners with three equivalent O(4)Ca2Co2 trigonal pyramids, corners with six equivalent O(1)CaCo3 trigonal pyramids, and edges with three equivalent O(4)Ca2Co2 trigonal pyramids. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), and two equivalent Co(2) atoms to form distorted OCa2Co2 trigonal pyramids that share  a cornercorner with one O(3)CaCo3 trigonal pyramid, corners with two equivalent O(4)Ca2Co2 trigonal pyramids, corners with seven equivalent O(1)CaCo3 trigonal pyramids,  an edgeedge with one O(3)CaCo3 trigonal pyramid, and edges with two equivalent O(4)Ca2Co2 trigonal pyramids. is represented by the CIF file [CIF]
data_Ca(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.368
_cell_length_b   6.368
_cell_length_c   6.368
_cell_angle_alpha   57.284
_cell_angle_beta   57.284
_cell_angle_gamma   57.284
_symmetry_Int_Tables_number   1
_cell_volume   171.199
_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
  Ca  Ca0  1  0.002  0.002  0.002  1.0
  Ca  Ca1  1  0.626  0.626  0.626  1.0
  Co  Co2  1  0.235  0.235  0.235  1.0
  Co  Co3  1  0.627  0.627  0.121  1.0
  Co  Co4  1  0.121  0.627  0.627  1.0
  Co  Co5  1  0.627  0.121  0.627  1.0
  O  O6  1  0.369  0.842  0.369  1.0
  O  O7  1  0.842  0.369  0.369  1.0
  O  O8  1  0.369  0.369  0.842  1.0
  O  O9  1  0.382  0.382  0.382  1.0
  O  O10  1  0.862  0.862  0.862  1.0
  O  O11  1  0.879  0.879  0.431  1.0
  O  O12  1  0.431  0.879  0.879  1.0
  O  O13  1  0.879  0.431  0.879  1.0
[/CIF]
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The material described by CaCo2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(3) and three equivalent O(4) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-73°. In the second Ca site, Ca(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form distorted CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Co(1)O4 tetrahedra, and edges with six equivalent Co(2)O6 octahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2) and three equivalent O(1) atoms to form CoO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-63°. In the second Co site, Co(2) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Co(1)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(2), one Co(1), and two equivalent Co(2) atoms to form distorted OCaCo3 trigonal pyramids that share corners with two equivalent O(1)CaCo3 trigonal pyramids, corners with two equivalent O(3)CaCo3 trigonal pyramids, corners with seven equivalent O(4)Ca2Co2 trigonal pyramids, and edges with two equivalent O(1)CaCo3 trigonal pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Co(1) and three equivalent Co(2) atoms. In the third O site, O(3) is bonded to one Ca(1) and three equivalent Co(2) atoms to form distorted OCaCo3 trigonal pyramids that share corners with three equivalent O(4)Ca2Co2 trigonal pyramids, corners with six equivalent O(1)CaCo3 trigonal pyramids, and edges with three equivalent O(4)Ca2Co2 trigonal pyramids. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), and two equivalent Co(2) atoms to form distorted OCa2Co2 trigonal pyramids that share  a cornercorner with one O(3)CaCo3 trigonal pyramid, corners with two equivalent O(4)Ca2Co2 trigonal pyramids, corners with seven equivalent O(1)CaCo3 trigonal pyramids,  an edgeedge with one O(3)CaCo3 trigonal pyramid, and edges with two equivalent O(4)Ca2Co2 trigonal pyramids. is represented by the CIF file [CIF]
data_Ca(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.368
_cell_length_b   6.368
_cell_length_c   6.368
_cell_angle_alpha   57.284
_cell_angle_beta   57.284
_cell_angle_gamma   57.284
_symmetry_Int_Tables_number   1
_cell_volume   171.199
_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
  Ca  Ca0  1  0.002  0.002  0.002  1.0
  Ca  Ca1  1  0.626  0.626  0.626  1.0
  Co  Co2  1  0.235  0.235  0.235  1.0
  Co  Co3  1  0.627  0.627  0.121  1.0
  Co  Co4  1  0.121  0.627  0.627  1.0
  Co  Co5  1  0.627  0.121  0.627  1.0
  O  O6  1  0.369  0.842  0.369  1.0
  O  O7  1  0.842  0.369  0.369  1.0
  O  O8  1  0.369  0.369  0.842  1.0
  O  O9  1  0.382  0.382  0.382  1.0
  O  O10  1  0.862  0.862  0.862  1.0
  O  O11  1  0.879  0.879  0.431  1.0
  O  O12  1  0.431  0.879  0.879  1.0
  O  O13  1  0.879  0.431  0.879  1.0
[/CIF]
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