The material structure described by CaCo2O4 crystallizes in the monoclinic Pc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(4), one O(5), two equivalent O(3), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 9-40°. In the second Co site, Co(2) is bonded to one O(1), one O(7), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 4-41°. In the third Co site, Co(3) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 9-40°. In the fourth Co site, Co(4) is bonded to one O(6), one O(7), two equivalent O(4), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 4-41°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), one Co(2), and two equivalent Co(3) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, corners with two equivalent O(5)Ca2Co2 trigonal pyramids, corners with three equivalent O(7)Ca2Co2 trigonal pyramids,  an edgeedge with one O(3)Ca2Co4 octahedra, edges with two equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(6)Ca2Co3 trigonal bipyramid, edges with two equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(2)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(7)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-46°. In the second O site, O(2) is bonded to two equivalent Ca(1), one Co(3), and two equivalent Co(2) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(7)Ca2Co2 trigonal pyramids, corners with three equivalent O(5)Ca2Co2 trigonal pyramids,  an edgeedge with one O(8)Ca2Co4 octahedra, edges with two equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(4)Ca2Co3 trigonal bipyramid, edges with two equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(2)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(5)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 7-47°. In the third O site, O(3) is bonded to two equivalent Ca(1), two equivalent Co(1), and two equivalent Co(3) atoms to form distorted OCa2Co4 octahedra that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, edges with two equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(1)Ca2Co3 trigonal bipyramid,  an edgeedge with one O(6)Ca2Co3 trigonal bipyramid, edges with two equivalent O(2)Ca2Co3 trigonal bipyramids, edges with two equivalent O(4)Ca2Co3 trigonal bipyramids, and edges with four equivalent O(5)Ca2Co2 trigonal pyramids. The corner-sharing octahedral tilt angles are 47°. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Co(1), and two equivalent Co(4) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(7)Ca2Co2 trigonal pyramids, corners with three equivalent O(5)Ca2Co2 trigonal pyramids,  an edgeedge with one O(8)Ca2Co4 octahedra, edges with two equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(2)Ca2Co3 trigonal bipyramid, edges with two equivalent O(4)Ca2Co3 trigonal bipyramids, edges with two equivalent O(6)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(5)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-49°. In the fifth O site, O(5) is bonded to two equivalent Ca(1), one Co(1), and one Co(3) atom to form distorted OCa2Co2 trigonal pyramids that share corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, corners with three equivalent O(2)Ca2Co3 trigonal bipyramids, corners with three equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(5)Ca2Co2 trigonal pyramids, edges with four equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(2)Ca2Co3 trigonal bipyramid, and  an edgeedge with one O(4)Ca2Co3 trigonal bipyramid. In the sixth O site, O(6) is bonded to two equivalent Ca(2), one Co(4), and two equivalent Co(1) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(5)Ca2Co2 trigonal pyramids, corners with three equivalent O(7)Ca2Co2 trigonal pyramids,  an edgeedge with one O(3)Ca2Co4 octahedra, edges with two equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(1)Ca2Co3 trigonal bipyramid, edges with two equivalent O(4)Ca2Co3 trigonal bipyramids, edges with two equivalent O(6)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(7)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 8-44°. In the seventh O site, O(7) is bonded to two equivalent Ca(2), one Co(2), and one Co(4) atom to form distorted OCa2Co2 trigonal pyramids that share corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with three equivalent O(1)Ca2Co3 trigonal bipyramids, corners with three equivalent O(6)Ca2Co3 trigonal bipyramids, corners with two equivalent O(7)Ca2Co2 trigonal pyramids, edges with four equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(1)Ca2Co3 trigonal bipyramid, and  an edgeedge with one O(6)Ca2Co3 trigonal bipyramid. In the eighth O site, O(8) is bonded to two equivalent Ca(2), two equivalent Co(2), and two equivalent Co(4) atoms to form OCa2Co4 octahedra that share corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, edges with two equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(2)Ca2Co3 trigonal bipyramid,  an edgeedge with one O(4)Ca2Co3 trigonal bipyramid, edges with two equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(6)Ca2Co3 trigonal bipyramids, and edges with four equivalent O(7)Ca2Co2 trigonal pyramids. The corner-sharing octahedral tilt angles are 46°. is represented by the CIF file [CIF]
data_Ca(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.881
_cell_length_b   3.141
_cell_length_c   9.715
_cell_angle_alpha   89.718
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   301.507
_cell_formula_units_Z   4
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  0.104  0.735  0.249  1.0
  Ca  Ca1  1  0.896  0.735  0.749  1.0
  Ca  Ca2  1  0.605  0.271  0.249  1.0
  Ca  Ca3  1  0.395  0.271  0.749  1.0
  Co  Co4  1  0.862  0.264  0.430  1.0
  Co  Co5  1  0.138  0.264  0.930  1.0
  Co  Co6  1  0.636  0.744  0.933  1.0
  Co  Co7  1  0.138  0.245  0.566  1.0
  Co  Co8  1  0.637  0.749  0.567  1.0
  Co  Co9  1  0.862  0.245  0.066  1.0
  Co  Co10  1  0.363  0.749  0.067  1.0
  Co  Co11  1  0.364  0.744  0.433  1.0
  O  O12  1  0.727  0.795  0.106  1.0
  O  O13  1  0.774  0.250  0.894  1.0
  O  O14  1  0.996  0.660  0.003  1.0
  O  O15  1  0.226  0.242  0.107  1.0
  O  O16  1  0.226  0.250  0.394  1.0
  O  O17  1  0.072  0.239  0.751  1.0
  O  O18  1  0.274  0.761  0.892  1.0
  O  O19  1  0.569  0.765  0.751  1.0
  O  O20  1  0.004  0.660  0.503  1.0
  O  O21  1  0.499  0.281  0.002  1.0
  O  O22  1  0.726  0.761  0.392  1.0
  O  O23  1  0.431  0.765  0.251  1.0
  O  O24  1  0.928  0.239  0.251  1.0
  O  O25  1  0.501  0.281  0.502  1.0
  O  O26  1  0.273  0.795  0.606  1.0
  O  O27  1  0.774  0.242  0.607  1.0
[/CIF]
.
The material structure described by CaCo2O4 crystallizes in the monoclinic Pc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(4), one O(5), two equivalent O(3), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 9-40°. In the second Co site, Co(2) is bonded to one O(1), one O(7), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 4-41°. In the third Co site, Co(3) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 9-40°. In the fourth Co site, Co(4) is bonded to one O(6), one O(7), two equivalent O(4), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 4-41°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), one Co(2), and two equivalent Co(3) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, corners with two equivalent O(5)Ca2Co2 trigonal pyramids, corners with three equivalent O(7)Ca2Co2 trigonal pyramids,  an edgeedge with one O(3)Ca2Co4 octahedra, edges with two equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(6)Ca2Co3 trigonal bipyramid, edges with two equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(2)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(7)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-46°. In the second O site, O(2) is bonded to two equivalent Ca(1), one Co(3), and two equivalent Co(2) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(7)Ca2Co2 trigonal pyramids, corners with three equivalent O(5)Ca2Co2 trigonal pyramids,  an edgeedge with one O(8)Ca2Co4 octahedra, edges with two equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(4)Ca2Co3 trigonal bipyramid, edges with two equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(2)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(5)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 7-47°. In the third O site, O(3) is bonded to two equivalent Ca(1), two equivalent Co(1), and two equivalent Co(3) atoms to form distorted OCa2Co4 octahedra that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, edges with two equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(1)Ca2Co3 trigonal bipyramid,  an edgeedge with one O(6)Ca2Co3 trigonal bipyramid, edges with two equivalent O(2)Ca2Co3 trigonal bipyramids, edges with two equivalent O(4)Ca2Co3 trigonal bipyramids, and edges with four equivalent O(5)Ca2Co2 trigonal pyramids. The corner-sharing octahedral tilt angles are 47°. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Co(1), and two equivalent Co(4) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(7)Ca2Co2 trigonal pyramids, corners with three equivalent O(5)Ca2Co2 trigonal pyramids,  an edgeedge with one O(8)Ca2Co4 octahedra, edges with two equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(2)Ca2Co3 trigonal bipyramid, edges with two equivalent O(4)Ca2Co3 trigonal bipyramids, edges with two equivalent O(6)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(5)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-49°. In the fifth O site, O(5) is bonded to two equivalent Ca(1), one Co(1), and one Co(3) atom to form distorted OCa2Co2 trigonal pyramids that share corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, corners with three equivalent O(2)Ca2Co3 trigonal bipyramids, corners with three equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(5)Ca2Co2 trigonal pyramids, edges with four equivalent O(3)Ca2Co4 octahedra,  an edgeedge with one O(2)Ca2Co3 trigonal bipyramid, and  an edgeedge with one O(4)Ca2Co3 trigonal bipyramid. In the sixth O site, O(6) is bonded to two equivalent Ca(2), one Co(4), and two equivalent Co(1) atoms to form distorted OCa2Co3 trigonal bipyramids that share corners with two equivalent O(3)Ca2Co4 octahedra, corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(5)Ca2Co2 trigonal pyramids, corners with three equivalent O(7)Ca2Co2 trigonal pyramids,  an edgeedge with one O(3)Ca2Co4 octahedra, edges with two equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(1)Ca2Co3 trigonal bipyramid, edges with two equivalent O(4)Ca2Co3 trigonal bipyramids, edges with two equivalent O(6)Ca2Co3 trigonal bipyramids, and  an edgeedge with one O(7)Ca2Co2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 8-44°. In the seventh O site, O(7) is bonded to two equivalent Ca(2), one Co(2), and one Co(4) atom to form distorted OCa2Co2 trigonal pyramids that share corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with three equivalent O(1)Ca2Co3 trigonal bipyramids, corners with three equivalent O(6)Ca2Co3 trigonal bipyramids, corners with two equivalent O(7)Ca2Co2 trigonal pyramids, edges with four equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(1)Ca2Co3 trigonal bipyramid, and  an edgeedge with one O(6)Ca2Co3 trigonal bipyramid. In the eighth O site, O(8) is bonded to two equivalent Ca(2), two equivalent Co(2), and two equivalent Co(4) atoms to form OCa2Co4 octahedra that share corners with two equivalent O(8)Ca2Co4 octahedra, corners with two equivalent O(1)Ca2Co3 trigonal bipyramids, corners with two equivalent O(2)Ca2Co3 trigonal bipyramids, corners with two equivalent O(4)Ca2Co3 trigonal bipyramids, corners with two equivalent O(6)Ca2Co3 trigonal bipyramids, edges with two equivalent O(8)Ca2Co4 octahedra,  an edgeedge with one O(2)Ca2Co3 trigonal bipyramid,  an edgeedge with one O(4)Ca2Co3 trigonal bipyramid, edges with two equivalent O(1)Ca2Co3 trigonal bipyramids, edges with two equivalent O(6)Ca2Co3 trigonal bipyramids, and edges with four equivalent O(7)Ca2Co2 trigonal pyramids. The corner-sharing octahedral tilt angles are 46°. is represented by the CIF file [CIF]
data_Ca(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.881
_cell_length_b   3.141
_cell_length_c   9.715
_cell_angle_alpha   89.718
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   301.507
_cell_formula_units_Z   4
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  0.104  0.735  0.249  1.0
  Ca  Ca1  1  0.896  0.735  0.749  1.0
  Ca  Ca2  1  0.605  0.271  0.249  1.0
  Ca  Ca3  1  0.395  0.271  0.749  1.0
  Co  Co4  1  0.862  0.264  0.430  1.0
  Co  Co5  1  0.138  0.264  0.930  1.0
  Co  Co6  1  0.636  0.744  0.933  1.0
  Co  Co7  1  0.138  0.245  0.566  1.0
  Co  Co8  1  0.637  0.749  0.567  1.0
  Co  Co9  1  0.862  0.245  0.066  1.0
  Co  Co10  1  0.363  0.749  0.067  1.0
  Co  Co11  1  0.364  0.744  0.433  1.0
  O  O12  1  0.727  0.795  0.106  1.0
  O  O13  1  0.774  0.250  0.894  1.0
  O  O14  1  0.996  0.660  0.003  1.0
  O  O15  1  0.226  0.242  0.107  1.0
  O  O16  1  0.226  0.250  0.394  1.0
  O  O17  1  0.072  0.239  0.751  1.0
  O  O18  1  0.274  0.761  0.892  1.0
  O  O19  1  0.569  0.765  0.751  1.0
  O  O20  1  0.004  0.660  0.503  1.0
  O  O21  1  0.499  0.281  0.002  1.0
  O  O22  1  0.726  0.761  0.392  1.0
  O  O23  1  0.431  0.765  0.251  1.0
  O  O24  1  0.928  0.239  0.251  1.0
  O  O25  1  0.501  0.281  0.502  1.0
  O  O26  1  0.273  0.795  0.606  1.0
  O  O27  1  0.774  0.242  0.607  1.0
[/CIF]
.