The structure described by CaCo2O4 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Co(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 0-41°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and three equivalent Co(1) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with four equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with five equivalent O(2)Ca2Co2 trigonal pyramids, edges with three equivalent O(3)Ca2Co4 octahedra, edges with five equivalent O(1)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(2)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 7-43°. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Co(1) atoms to form distorted OCa2Co2 trigonal pyramids that share corners with ten equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(2)Ca2Co2 trigonal pyramids, edges with four equivalent O(3)Ca2Co4 octahedra, and edges with two equivalent O(1)Ca2Co3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Ca(1) and four equivalent Co(1) atoms to form OCa2Co4 octahedra that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with eight equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(3)Ca2Co4 octahedra, edges with six equivalent O(1)Ca2Co3 trigonal bipyramids, and edges with four equivalent O(2)Ca2Co2 trigonal pyramids. The corner-sharing octahedral tilt angles are 47°. is represented by the CIF card [CIF]
data_Ca(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.188
_cell_length_b   5.188
_cell_length_c   9.785
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   145.039
_symmetry_Int_Tables_number   1
_cell_volume   150.913
_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  0.607  0.393  0.750  1.0
  Ca  Ca1  1  0.393  0.607  0.250  1.0
  Co  Co2  1  0.135  0.865  0.067  1.0
  Co  Co3  1  0.865  0.135  0.933  1.0
  Co  Co4  1  0.135  0.865  0.433  1.0
  Co  Co5  1  0.865  0.135  0.567  1.0
  O  O6  1  0.773  0.227  0.393  1.0
  O  O7  1  0.227  0.773  0.607  1.0
  O  O8  1  0.227  0.773  0.893  1.0
  O  O9  1  0.773  0.227  0.107  1.0
  O  O10  1  0.068  0.932  0.250  1.0
  O  O11  1  0.932  0.068  0.750  1.0
  O  O12  1  0.500  0.500  0.000  1.0
  O  O13  1  0.500  0.500  0.500  1.0
[/CIF]
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The structure described by CaCo2O4 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Co(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 0-41°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and three equivalent Co(1) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with four equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with five equivalent O(2)Ca2Co2 trigonal pyramids, edges with three equivalent O(3)Ca2Co4 octahedra, edges with five equivalent O(1)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(2)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 7-43°. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Co(1) atoms to form distorted OCa2Co2 trigonal pyramids that share corners with ten equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(2)Ca2Co2 trigonal pyramids, edges with four equivalent O(3)Ca2Co4 octahedra, and edges with two equivalent O(1)Ca2Co3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Ca(1) and four equivalent Co(1) atoms to form OCa2Co4 octahedra that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with eight equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(3)Ca2Co4 octahedra, edges with six equivalent O(1)Ca2Co3 trigonal bipyramids, and edges with four equivalent O(2)Ca2Co2 trigonal pyramids. The corner-sharing octahedral tilt angles are 47°. is represented by the CIF card [CIF]
data_Ca(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.188
_cell_length_b   5.188
_cell_length_c   9.785
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   145.039
_symmetry_Int_Tables_number   1
_cell_volume   150.913
_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  0.607  0.393  0.750  1.0
  Ca  Ca1  1  0.393  0.607  0.250  1.0
  Co  Co2  1  0.135  0.865  0.067  1.0
  Co  Co3  1  0.865  0.135  0.933  1.0
  Co  Co4  1  0.135  0.865  0.433  1.0
  Co  Co5  1  0.865  0.135  0.567  1.0
  O  O6  1  0.773  0.227  0.393  1.0
  O  O7  1  0.227  0.773  0.607  1.0
  O  O8  1  0.227  0.773  0.893  1.0
  O  O9  1  0.773  0.227  0.107  1.0
  O  O10  1  0.068  0.932  0.250  1.0
  O  O11  1  0.932  0.068  0.750  1.0
  O  O12  1  0.500  0.500  0.000  1.0
  O  O13  1  0.500  0.500  0.500  1.0
[/CIF]
.