The material described by CaCu3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(7) atoms to form CuO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Cu(1)O6 octahedra, and  an edgeedge with one Cu(2)O6 octahedra. In the second Cu site, Cu(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form CuO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(2)O6 octahedra, corners with three equivalent Cu(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-60°. In the second P site, P(2) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cu(2)O6 octahedra, corners with three equivalent Cu(1)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-64°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Cu(1), and one P(1) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one P(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Cu(1) and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one P(2) atom. In the fifth O site, O(2) is bonded to one Ca(1), one Cu(1), one Cu(2), and one P(1) atom to form distorted corner-sharing OCaCu2P tetrahedra. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaCu3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.857
_cell_length_b   7.335
_cell_length_c   9.458
_cell_angle_alpha   69.670
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   511.102
_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  0.000  0.500  0.000  1.0
  Ca  Ca1  1  0.500  0.500  0.500  1.0
  Cu  Cu2  1  0.130  0.810  0.522  1.0
  Cu  Cu3  1  0.630  0.190  0.978  1.0
  Cu  Cu4  1  0.870  0.190  0.478  1.0
  Cu  Cu5  1  0.370  0.810  0.022  1.0
  Cu  Cu6  1  0.000  0.000  0.000  1.0
  Cu  Cu7  1  0.500  0.000  0.500  1.0
  P  P8  1  0.947  0.406  0.700  1.0
  P  P9  1  0.447  0.594  0.800  1.0
  P  P10  1  0.053  0.594  0.300  1.0
  P  P11  1  0.553  0.406  0.200  1.0
  P  P12  1  0.208  0.107  0.696  1.0
  P  P13  1  0.708  0.893  0.804  1.0
  P  P14  1  0.792  0.893  0.304  1.0
  P  P15  1  0.292  0.107  0.196  1.0
  O  O16  1  0.381  0.158  0.615  1.0
  O  O17  1  0.881  0.842  0.885  1.0
  O  O18  1  0.619  0.842  0.385  1.0
  O  O19  1  0.119  0.158  0.115  1.0
  O  O20  1  0.398  0.702  0.634  1.0
  O  O21  1  0.898  0.298  0.866  1.0
  O  O22  1  0.602  0.298  0.366  1.0
  O  O23  1  0.102  0.702  0.134  1.0
  O  O24  1  0.818  0.375  0.588  1.0
  O  O25  1  0.318  0.625  0.912  1.0
  O  O26  1  0.182  0.625  0.412  1.0
  O  O27  1  0.682  0.375  0.088  1.0
  O  O28  1  0.128  0.317  0.672  1.0
  O  O29  1  0.628  0.683  0.828  1.0
  O  O30  1  0.872  0.683  0.328  1.0
  O  O31  1  0.372  0.317  0.172  1.0
  O  O32  1  0.511  0.616  0.182  1.0
  O  O33  1  0.011  0.384  0.318  1.0
  O  O34  1  0.489  0.384  0.818  1.0
  O  O35  1  0.989  0.616  0.682  1.0
  O  O36  1  0.785  0.991  0.130  1.0
  O  O37  1  0.285  0.009  0.370  1.0
  O  O38  1  0.215  0.009  0.870  1.0
  O  O39  1  0.715  0.991  0.630  1.0
  O  O40  1  0.412  0.004  0.122  1.0
  O  O41  1  0.912  0.996  0.378  1.0
  O  O42  1  0.588  0.996  0.878  1.0
  O  O43  1  0.088  0.004  0.622  1.0
[/CIF]
.
The material described by CaCu3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(7) atoms to form CuO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Cu(1)O6 octahedra, and  an edgeedge with one Cu(2)O6 octahedra. In the second Cu site, Cu(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form CuO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(2)O6 octahedra, corners with three equivalent Cu(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-60°. In the second P site, P(2) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cu(2)O6 octahedra, corners with three equivalent Cu(1)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-64°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Cu(1), and one P(1) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one P(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Cu(1) and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one P(2) atom. In the fifth O site, O(2) is bonded to one Ca(1), one Cu(1), one Cu(2), and one P(1) atom to form distorted corner-sharing OCaCu2P tetrahedra. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaCu3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.857
_cell_length_b   7.335
_cell_length_c   9.458
_cell_angle_alpha   69.670
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   511.102
_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  0.000  0.500  0.000  1.0
  Ca  Ca1  1  0.500  0.500  0.500  1.0
  Cu  Cu2  1  0.130  0.810  0.522  1.0
  Cu  Cu3  1  0.630  0.190  0.978  1.0
  Cu  Cu4  1  0.870  0.190  0.478  1.0
  Cu  Cu5  1  0.370  0.810  0.022  1.0
  Cu  Cu6  1  0.000  0.000  0.000  1.0
  Cu  Cu7  1  0.500  0.000  0.500  1.0
  P  P8  1  0.947  0.406  0.700  1.0
  P  P9  1  0.447  0.594  0.800  1.0
  P  P10  1  0.053  0.594  0.300  1.0
  P  P11  1  0.553  0.406  0.200  1.0
  P  P12  1  0.208  0.107  0.696  1.0
  P  P13  1  0.708  0.893  0.804  1.0
  P  P14  1  0.792  0.893  0.304  1.0
  P  P15  1  0.292  0.107  0.196  1.0
  O  O16  1  0.381  0.158  0.615  1.0
  O  O17  1  0.881  0.842  0.885  1.0
  O  O18  1  0.619  0.842  0.385  1.0
  O  O19  1  0.119  0.158  0.115  1.0
  O  O20  1  0.398  0.702  0.634  1.0
  O  O21  1  0.898  0.298  0.866  1.0
  O  O22  1  0.602  0.298  0.366  1.0
  O  O23  1  0.102  0.702  0.134  1.0
  O  O24  1  0.818  0.375  0.588  1.0
  O  O25  1  0.318  0.625  0.912  1.0
  O  O26  1  0.182  0.625  0.412  1.0
  O  O27  1  0.682  0.375  0.088  1.0
  O  O28  1  0.128  0.317  0.672  1.0
  O  O29  1  0.628  0.683  0.828  1.0
  O  O30  1  0.872  0.683  0.328  1.0
  O  O31  1  0.372  0.317  0.172  1.0
  O  O32  1  0.511  0.616  0.182  1.0
  O  O33  1  0.011  0.384  0.318  1.0
  O  O34  1  0.489  0.384  0.818  1.0
  O  O35  1  0.989  0.616  0.682  1.0
  O  O36  1  0.785  0.991  0.130  1.0
  O  O37  1  0.285  0.009  0.370  1.0
  O  O38  1  0.215  0.009  0.870  1.0
  O  O39  1  0.715  0.991  0.630  1.0
  O  O40  1  0.412  0.004  0.122  1.0
  O  O41  1  0.912  0.996  0.378  1.0
  O  O42  1  0.588  0.996  0.878  1.0
  O  O43  1  0.088  0.004  0.622  1.0
[/CIF]
.