The material described by Ca2Cu(HCOO)6 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to one O(2), one O(3), one O(5), two equivalent O(4), and two equivalent O(6) atoms to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Cu(1)O6 octahedra and edges with two equivalent Ca(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 42°. Cu(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids and edges with two equivalent Cu(1)O6 octahedra. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one H(1), one O(1), and one O(2) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one H(2), one O(3), and one O(4) atom. In the third C site, C(3) is bonded in a trigonal planar geometry to one H(3), one O(5), and one O(6) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. There are six inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Ca(1) and one C(1) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one C(2) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one C(2) atom. In the fourth O site, O(5) is bonded in a distorted linear geometry to one Ca(1) and one C(3) atom. In the fifth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one C(3) atom. In the sixth O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Cu(1) and one C(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2CuH6(CO2)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.132
_cell_length_b   12.132
_cell_length_c   6.567
_cell_angle_alpha   80.210
_cell_angle_beta   80.210
_cell_angle_gamma   43.163
_symmetry_Int_Tables_number   1
_cell_volume   650.034
_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  0.472  0.210  0.937  1.0
  Ca  Ca1  1  0.790  0.528  0.563  1.0
  Ca  Ca2  1  0.528  0.790  0.063  1.0
  Ca  Ca3  1  0.210  0.472  0.437  1.0
  Cu  Cu4  1  0.905  0.095  0.750  1.0
  Cu  Cu5  1  0.095  0.905  0.250  1.0
  H  H6  1  0.919  0.845  0.871  1.0
  H  H7  1  0.155  0.081  0.629  1.0
  H  H8  1  0.081  0.155  0.129  1.0
  H  H9  1  0.845  0.919  0.371  1.0
  H  H10  1  0.320  0.641  0.937  1.0
  H  H11  1  0.359  0.680  0.563  1.0
  H  H12  1  0.680  0.359  0.063  1.0
  H  H13  1  0.641  0.320  0.437  1.0
  H  H14  1  0.317  0.112  0.495  1.0
  H  H15  1  0.888  0.683  0.005  1.0
  H  H16  1  0.683  0.888  0.505  1.0
  H  H17  1  0.112  0.317  0.995  1.0
  C  C18  1  0.995  0.803  0.723  1.0
  C  C19  1  0.197  0.005  0.777  1.0
  C  C20  1  0.005  0.197  0.277  1.0
  C  C21  1  0.803  0.995  0.223  1.0
  C  C22  1  0.292  0.593  0.070  1.0
  C  C23  1  0.407  0.708  0.430  1.0
  C  C24  1  0.708  0.407  0.930  1.0
  C  C25  1  0.593  0.292  0.570  1.0
  C  C26  1  0.347  0.125  0.330  1.0
  C  C27  1  0.875  0.653  0.170  1.0
  C  C28  1  0.653  0.875  0.670  1.0
  C  C29  1  0.125  0.347  0.830  1.0
  O  O30  1  0.017  0.889  0.633  1.0
  O  O31  1  0.111  0.983  0.867  1.0
  O  O32  1  0.983  0.111  0.367  1.0
  O  O33  1  0.889  0.017  0.133  1.0
  O  O34  1  0.052  0.678  0.656  1.0
  O  O35  1  0.322  0.948  0.844  1.0
  O  O36  1  0.948  0.322  0.344  1.0
  O  O37  1  0.678  0.052  0.156  1.0
  O  O38  1  0.685  0.194  0.718  1.0
  O  O39  1  0.806  0.315  0.782  1.0
  O  O40  1  0.315  0.806  0.282  1.0
  O  O41  1  0.194  0.685  0.218  1.0
  O  O42  1  0.356  0.452  0.073  1.0
  O  O43  1  0.548  0.644  0.427  1.0
  O  O44  1  0.644  0.548  0.927  1.0
  O  O45  1  0.452  0.356  0.573  1.0
  O  O46  1  0.603  0.977  0.791  1.0
  O  O47  1  0.023  0.397  0.709  1.0
  O  O48  1  0.397  0.023  0.209  1.0
  O  O49  1  0.977  0.603  0.291  1.0
  O  O50  1  0.329  0.243  0.273  1.0
  O  O51  1  0.757  0.671  0.227  1.0
  O  O52  1  0.671  0.757  0.727  1.0
  O  O53  1  0.243  0.329  0.773  1.0
[/CIF]
.
The material described by Ca2Cu(HCOO)6 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to one O(2), one O(3), one O(5), two equivalent O(4), and two equivalent O(6) atoms to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Cu(1)O6 octahedra and edges with two equivalent Ca(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 42°. Cu(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids and edges with two equivalent Cu(1)O6 octahedra. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one H(1), one O(1), and one O(2) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one H(2), one O(3), and one O(4) atom. In the third C site, C(3) is bonded in a trigonal planar geometry to one H(3), one O(5), and one O(6) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. There are six inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Ca(1) and one C(1) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one C(2) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one C(2) atom. In the fourth O site, O(5) is bonded in a distorted linear geometry to one Ca(1) and one C(3) atom. In the fifth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one C(3) atom. In the sixth O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Cu(1) and one C(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2CuH6(CO2)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.132
_cell_length_b   12.132
_cell_length_c   6.567
_cell_angle_alpha   80.210
_cell_angle_beta   80.210
_cell_angle_gamma   43.163
_symmetry_Int_Tables_number   1
_cell_volume   650.034
_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  0.472  0.210  0.937  1.0
  Ca  Ca1  1  0.790  0.528  0.563  1.0
  Ca  Ca2  1  0.528  0.790  0.063  1.0
  Ca  Ca3  1  0.210  0.472  0.437  1.0
  Cu  Cu4  1  0.905  0.095  0.750  1.0
  Cu  Cu5  1  0.095  0.905  0.250  1.0
  H  H6  1  0.919  0.845  0.871  1.0
  H  H7  1  0.155  0.081  0.629  1.0
  H  H8  1  0.081  0.155  0.129  1.0
  H  H9  1  0.845  0.919  0.371  1.0
  H  H10  1  0.320  0.641  0.937  1.0
  H  H11  1  0.359  0.680  0.563  1.0
  H  H12  1  0.680  0.359  0.063  1.0
  H  H13  1  0.641  0.320  0.437  1.0
  H  H14  1  0.317  0.112  0.495  1.0
  H  H15  1  0.888  0.683  0.005  1.0
  H  H16  1  0.683  0.888  0.505  1.0
  H  H17  1  0.112  0.317  0.995  1.0
  C  C18  1  0.995  0.803  0.723  1.0
  C  C19  1  0.197  0.005  0.777  1.0
  C  C20  1  0.005  0.197  0.277  1.0
  C  C21  1  0.803  0.995  0.223  1.0
  C  C22  1  0.292  0.593  0.070  1.0
  C  C23  1  0.407  0.708  0.430  1.0
  C  C24  1  0.708  0.407  0.930  1.0
  C  C25  1  0.593  0.292  0.570  1.0
  C  C26  1  0.347  0.125  0.330  1.0
  C  C27  1  0.875  0.653  0.170  1.0
  C  C28  1  0.653  0.875  0.670  1.0
  C  C29  1  0.125  0.347  0.830  1.0
  O  O30  1  0.017  0.889  0.633  1.0
  O  O31  1  0.111  0.983  0.867  1.0
  O  O32  1  0.983  0.111  0.367  1.0
  O  O33  1  0.889  0.017  0.133  1.0
  O  O34  1  0.052  0.678  0.656  1.0
  O  O35  1  0.322  0.948  0.844  1.0
  O  O36  1  0.948  0.322  0.344  1.0
  O  O37  1  0.678  0.052  0.156  1.0
  O  O38  1  0.685  0.194  0.718  1.0
  O  O39  1  0.806  0.315  0.782  1.0
  O  O40  1  0.315  0.806  0.282  1.0
  O  O41  1  0.194  0.685  0.218  1.0
  O  O42  1  0.356  0.452  0.073  1.0
  O  O43  1  0.548  0.644  0.427  1.0
  O  O44  1  0.644  0.548  0.927  1.0
  O  O45  1  0.452  0.356  0.573  1.0
  O  O46  1  0.603  0.977  0.791  1.0
  O  O47  1  0.023  0.397  0.709  1.0
  O  O48  1  0.397  0.023  0.209  1.0
  O  O49  1  0.977  0.603  0.291  1.0
  O  O50  1  0.329  0.243  0.273  1.0
  O  O51  1  0.757  0.671  0.227  1.0
  O  O52  1  0.671  0.757  0.727  1.0
  O  O53  1  0.243  0.329  0.773  1.0
[/CIF]
.