The crystal structure described by CaCuP2O7 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(5), one O(6), two equivalent O(3), and two equivalent O(7) atoms. Cu(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one P(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one P(1) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Ca(1), one Cu(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted single-bond geometry to one Ca(1), one Cu(1), and one P(1) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one P(2) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. is represented by the CIF card [CIF]
data_CaCuP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.025
_cell_length_b   5.229
_cell_length_c   13.239
_cell_angle_alpha   68.192
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   515.816
_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  0.177  0.989  0.223  1.0
  Ca  Ca1  1  0.677  0.011  0.277  1.0
  Ca  Ca2  1  0.823  0.011  0.777  1.0
  Ca  Ca3  1  0.323  0.989  0.723  1.0
  Cu  Cu4  1  0.360  0.315  0.389  1.0
  Cu  Cu5  1  0.860  0.685  0.111  1.0
  Cu  Cu6  1  0.640  0.685  0.611  1.0
  Cu  Cu7  1  0.140  0.315  0.889  1.0
  P  P8  1  0.299  0.674  0.515  1.0
  P  P9  1  0.799  0.326  0.985  1.0
  P  P10  1  0.701  0.326  0.485  1.0
  P  P11  1  0.201  0.674  0.015  1.0
  P  P12  1  0.972  0.410  0.336  1.0
  P  P13  1  0.472  0.590  0.164  1.0
  P  P14  1  0.028  0.590  0.664  1.0
  P  P15  1  0.528  0.410  0.836  1.0
  O  O16  1  0.315  0.884  0.402  1.0
  O  O17  1  0.815  0.116  0.098  1.0
  O  O18  1  0.685  0.116  0.598  1.0
  O  O19  1  0.185  0.884  0.902  1.0
  O  O20  1  0.165  0.374  0.028  1.0
  O  O21  1  0.665  0.626  0.472  1.0
  O  O22  1  0.835  0.626  0.972  1.0
  O  O23  1  0.335  0.374  0.528  1.0
  O  O24  1  0.456  0.822  0.205  1.0
  O  O25  1  0.956  0.178  0.295  1.0
  O  O26  1  0.544  0.178  0.795  1.0
  O  O27  1  0.044  0.822  0.705  1.0
  O  O28  1  0.394  0.689  0.045  1.0
  O  O29  1  0.894  0.311  0.455  1.0
  O  O30  1  0.606  0.311  0.955  1.0
  O  O31  1  0.106  0.689  0.545  1.0
  O  O32  1  0.350  0.496  0.846  1.0
  O  O33  1  0.850  0.504  0.654  1.0
  O  O34  1  0.650  0.504  0.154  1.0
  O  O35  1  0.150  0.496  0.346  1.0
  O  O36  1  0.398  0.748  0.599  1.0
  O  O37  1  0.898  0.252  0.901  1.0
  O  O38  1  0.602  0.252  0.401  1.0
  O  O39  1  0.102  0.748  0.099  1.0
  O  O40  1  0.123  0.330  0.734  1.0
  O  O41  1  0.623  0.670  0.766  1.0
  O  O42  1  0.877  0.670  0.266  1.0
  O  O43  1  0.377  0.330  0.234  1.0
[/CIF]
.
The crystal structure described by CaCuP2O7 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(5), one O(6), two equivalent O(3), and two equivalent O(7) atoms. Cu(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one P(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one P(1) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Ca(1), one Cu(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted single-bond geometry to one Ca(1), one Cu(1), and one P(1) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one P(2) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. is represented by the CIF card [CIF]
data_CaCuP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.025
_cell_length_b   5.229
_cell_length_c   13.239
_cell_angle_alpha   68.192
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   515.816
_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  0.177  0.989  0.223  1.0
  Ca  Ca1  1  0.677  0.011  0.277  1.0
  Ca  Ca2  1  0.823  0.011  0.777  1.0
  Ca  Ca3  1  0.323  0.989  0.723  1.0
  Cu  Cu4  1  0.360  0.315  0.389  1.0
  Cu  Cu5  1  0.860  0.685  0.111  1.0
  Cu  Cu6  1  0.640  0.685  0.611  1.0
  Cu  Cu7  1  0.140  0.315  0.889  1.0
  P  P8  1  0.299  0.674  0.515  1.0
  P  P9  1  0.799  0.326  0.985  1.0
  P  P10  1  0.701  0.326  0.485  1.0
  P  P11  1  0.201  0.674  0.015  1.0
  P  P12  1  0.972  0.410  0.336  1.0
  P  P13  1  0.472  0.590  0.164  1.0
  P  P14  1  0.028  0.590  0.664  1.0
  P  P15  1  0.528  0.410  0.836  1.0
  O  O16  1  0.315  0.884  0.402  1.0
  O  O17  1  0.815  0.116  0.098  1.0
  O  O18  1  0.685  0.116  0.598  1.0
  O  O19  1  0.185  0.884  0.902  1.0
  O  O20  1  0.165  0.374  0.028  1.0
  O  O21  1  0.665  0.626  0.472  1.0
  O  O22  1  0.835  0.626  0.972  1.0
  O  O23  1  0.335  0.374  0.528  1.0
  O  O24  1  0.456  0.822  0.205  1.0
  O  O25  1  0.956  0.178  0.295  1.0
  O  O26  1  0.544  0.178  0.795  1.0
  O  O27  1  0.044  0.822  0.705  1.0
  O  O28  1  0.394  0.689  0.045  1.0
  O  O29  1  0.894  0.311  0.455  1.0
  O  O30  1  0.606  0.311  0.955  1.0
  O  O31  1  0.106  0.689  0.545  1.0
  O  O32  1  0.350  0.496  0.846  1.0
  O  O33  1  0.850  0.504  0.654  1.0
  O  O34  1  0.650  0.504  0.154  1.0
  O  O35  1  0.150  0.496  0.346  1.0
  O  O36  1  0.398  0.748  0.599  1.0
  O  O37  1  0.898  0.252  0.901  1.0
  O  O38  1  0.602  0.252  0.401  1.0
  O  O39  1  0.102  0.748  0.099  1.0
  O  O40  1  0.123  0.330  0.734  1.0
  O  O41  1  0.623  0.670  0.766  1.0
  O  O42  1  0.877  0.670  0.266  1.0
  O  O43  1  0.377  0.330  0.234  1.0
[/CIF]
.