The structure described by Ca(CuO2)2 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. Cu(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 CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-47°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and three equivalent Cu(1) atoms to form distorted OCa2Cu3 trigonal bipyramids that share corners with four equivalent O(3)Ca2Cu4 octahedra, corners with five equivalent O(2)Ca2Cu2 tetrahedra, corners with two equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with three equivalent O(3)Ca2Cu4 octahedra,  an edgeedge with one O(2)Ca2Cu2 tetrahedra, and edges with five equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-44°. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Cu(1) atoms to form distorted OCa2Cu2 tetrahedra that share corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with ten equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with four equivalent O(3)Ca2Cu4 octahedra, and edges with two equivalent O(1)Ca2Cu3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Ca(1) and four equivalent Cu(1) atoms to form OCa2Cu4 octahedra that share corners with two equivalent O(3)Ca2Cu4 octahedra, corners with eight equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with two equivalent O(3)Ca2Cu4 octahedra, edges with four equivalent O(2)Ca2Cu2 tetrahedra, and edges with six equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 47°. is represented by the CIF card [CIF]
data_Ca(CuO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.165
_cell_length_b   5.165
_cell_length_c   9.518
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   144.652
_symmetry_Int_Tables_number   1
_cell_volume   146.879
_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  0.606  0.394  0.750  1.0
  Ca  Ca1  1  0.394  0.606  0.250  1.0
  Cu  Cu2  1  0.137  0.863  0.069  1.0
  Cu  Cu3  1  0.863  0.137  0.931  1.0
  Cu  Cu4  1  0.137  0.863  0.431  1.0
  Cu  Cu5  1  0.863  0.137  0.569  1.0
  O  O6  1  0.773  0.227  0.394  1.0
  O  O7  1  0.227  0.773  0.606  1.0
  O  O8  1  0.227  0.773  0.894  1.0
  O  O9  1  0.773  0.227  0.106  1.0
  O  O10  1  0.061  0.939  0.250  1.0
  O  O11  1  0.939  0.061  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]
.
The structure described by Ca(CuO2)2 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. Cu(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 CuO6 octahedra. The corner-sharing octahedral tilt angles range from 0-47°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and three equivalent Cu(1) atoms to form distorted OCa2Cu3 trigonal bipyramids that share corners with four equivalent O(3)Ca2Cu4 octahedra, corners with five equivalent O(2)Ca2Cu2 tetrahedra, corners with two equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with three equivalent O(3)Ca2Cu4 octahedra,  an edgeedge with one O(2)Ca2Cu2 tetrahedra, and edges with five equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-44°. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Cu(1) atoms to form distorted OCa2Cu2 tetrahedra that share corners with two equivalent O(2)Ca2Cu2 tetrahedra, corners with ten equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with four equivalent O(3)Ca2Cu4 octahedra, and edges with two equivalent O(1)Ca2Cu3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Ca(1) and four equivalent Cu(1) atoms to form OCa2Cu4 octahedra that share corners with two equivalent O(3)Ca2Cu4 octahedra, corners with eight equivalent O(1)Ca2Cu3 trigonal bipyramids, edges with two equivalent O(3)Ca2Cu4 octahedra, edges with four equivalent O(2)Ca2Cu2 tetrahedra, and edges with six equivalent O(1)Ca2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 47°. is represented by the CIF card [CIF]
data_Ca(CuO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.165
_cell_length_b   5.165
_cell_length_c   9.518
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   144.652
_symmetry_Int_Tables_number   1
_cell_volume   146.879
_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  0.606  0.394  0.750  1.0
  Ca  Ca1  1  0.394  0.606  0.250  1.0
  Cu  Cu2  1  0.137  0.863  0.069  1.0
  Cu  Cu3  1  0.863  0.137  0.931  1.0
  Cu  Cu4  1  0.137  0.863  0.431  1.0
  Cu  Cu5  1  0.863  0.137  0.569  1.0
  O  O6  1  0.773  0.227  0.394  1.0
  O  O7  1  0.227  0.773  0.606  1.0
  O  O8  1  0.227  0.773  0.894  1.0
  O  O9  1  0.773  0.227  0.106  1.0
  O  O10  1  0.061  0.939  0.250  1.0
  O  O11  1  0.939  0.061  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]
.