The material described by Cu2P2O7 crystallizes in the monoclinic C2/c space group. Cu(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted CuO5 trigonal bipyramids that share corners with five equivalent P(1)O4 tetrahedra and edges with two equivalent Cu(1)O5 trigonal bipyramids. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with five equivalent Cu(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Cu(1) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Cu(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent P(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cu2P2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.345
_cell_length_b   5.345
_cell_length_c   9.206
_cell_angle_alpha   76.838
_cell_angle_beta   76.838
_cell_angle_gamma   98.358
_symmetry_Int_Tables_number   1
_cell_volume   243.927
_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
  Cu  Cu0  1  0.289  0.661  0.991  1.0
  Cu  Cu1  1  0.339  0.711  0.509  1.0
  Cu  Cu2  1  0.711  0.339  0.009  1.0
  Cu  Cu3  1  0.661  0.289  0.491  1.0
  P  P4  1  0.205  0.182  0.294  1.0
  P  P5  1  0.818  0.795  0.206  1.0
  P  P6  1  0.795  0.818  0.706  1.0
  P  P7  1  0.182  0.205  0.794  1.0
  O  O8  1  0.016  0.312  0.380  1.0
  O  O9  1  0.688  0.984  0.120  1.0
  O  O10  1  0.984  0.688  0.620  1.0
  O  O11  1  0.312  0.016  0.880  1.0
  O  O12  1  0.382  0.067  0.386  1.0
  O  O13  1  0.933  0.618  0.114  1.0
  O  O14  1  0.618  0.933  0.614  1.0
  O  O15  1  0.067  0.382  0.886  1.0
  O  O16  1  0.941  0.059  0.750  1.0
  O  O17  1  0.059  0.941  0.250  1.0
  O  O18  1  0.372  0.373  0.638  1.0
  O  O19  1  0.627  0.628  0.862  1.0
  O  O20  1  0.628  0.627  0.362  1.0
  O  O21  1  0.373  0.372  0.138  1.0
[/CIF]
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The material described by Cu2P2O7 crystallizes in the monoclinic C2/c space group. Cu(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted CuO5 trigonal bipyramids that share corners with five equivalent P(1)O4 tetrahedra and edges with two equivalent Cu(1)O5 trigonal bipyramids. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with five equivalent Cu(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Cu(1) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Cu(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent P(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cu2P2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.345
_cell_length_b   5.345
_cell_length_c   9.206
_cell_angle_alpha   76.838
_cell_angle_beta   76.838
_cell_angle_gamma   98.358
_symmetry_Int_Tables_number   1
_cell_volume   243.927
_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
  Cu  Cu0  1  0.289  0.661  0.991  1.0
  Cu  Cu1  1  0.339  0.711  0.509  1.0
  Cu  Cu2  1  0.711  0.339  0.009  1.0
  Cu  Cu3  1  0.661  0.289  0.491  1.0
  P  P4  1  0.205  0.182  0.294  1.0
  P  P5  1  0.818  0.795  0.206  1.0
  P  P6  1  0.795  0.818  0.706  1.0
  P  P7  1  0.182  0.205  0.794  1.0
  O  O8  1  0.016  0.312  0.380  1.0
  O  O9  1  0.688  0.984  0.120  1.0
  O  O10  1  0.984  0.688  0.620  1.0
  O  O11  1  0.312  0.016  0.880  1.0
  O  O12  1  0.382  0.067  0.386  1.0
  O  O13  1  0.933  0.618  0.114  1.0
  O  O14  1  0.618  0.933  0.614  1.0
  O  O15  1  0.067  0.382  0.886  1.0
  O  O16  1  0.941  0.059  0.750  1.0
  O  O17  1  0.059  0.941  0.250  1.0
  O  O18  1  0.372  0.373  0.638  1.0
  O  O19  1  0.627  0.628  0.862  1.0
  O  O20  1  0.628  0.627  0.362  1.0
  O  O21  1  0.373  0.372  0.138  1.0
[/CIF]
.