The structure described by CrP2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)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(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-47°. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-50°. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CrP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.235
_cell_length_b   8.047
_cell_length_c   9.359
_cell_angle_alpha   90.000
_cell_angle_beta   110.693
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   509.735
_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
  Cr  Cr0  1  0.273  0.492  0.747  1.0
  Cr  Cr1  1  0.273  0.008  0.247  1.0
  Cr  Cr2  1  0.727  0.992  0.753  1.0
  Cr  Cr3  1  0.727  0.508  0.253  1.0
  P  P4  1  0.073  0.239  0.944  1.0
  P  P5  1  0.073  0.261  0.444  1.0
  P  P6  1  0.927  0.739  0.556  1.0
  P  P7  1  0.927  0.761  0.056  1.0
  P  P8  1  0.325  0.798  0.551  1.0
  P  P9  1  0.675  0.298  0.949  1.0
  P  P10  1  0.325  0.702  0.051  1.0
  P  P11  1  0.675  0.202  0.449  1.0
  O  O12  1  0.009  0.586  0.657  1.0
  O  O13  1  0.009  0.914  0.157  1.0
  O  O14  1  0.991  0.086  0.843  1.0
  O  O15  1  0.991  0.414  0.343  1.0
  O  O16  1  0.200  0.354  0.892  1.0
  O  O17  1  0.200  0.146  0.392  1.0
  O  O18  1  0.800  0.854  0.608  1.0
  O  O19  1  0.800  0.646  0.108  1.0
  O  O20  1  0.110  0.850  0.551  1.0
  O  O21  1  0.110  0.650  0.051  1.0
  O  O22  1  0.890  0.350  0.949  1.0
  O  O23  1  0.890  0.150  0.449  1.0
  O  O24  1  0.326  0.679  0.889  1.0
  O  O25  1  0.326  0.821  0.389  1.0
  O  O26  1  0.674  0.179  0.611  1.0
  O  O27  1  0.674  0.321  0.111  1.0
  O  O28  1  0.191  0.311  0.610  1.0
  O  O29  1  0.191  0.189  0.110  1.0
  O  O30  1  0.809  0.811  0.890  1.0
  O  O31  1  0.809  0.689  0.390  1.0
  O  O32  1  0.360  0.617  0.601  1.0
  O  O33  1  0.640  0.117  0.899  1.0
  O  O34  1  0.360  0.883  0.101  1.0
  O  O35  1  0.640  0.383  0.399  1.0
  O  O36  1  0.537  0.419  0.833  1.0
  O  O37  1  0.463  0.919  0.667  1.0
  O  O38  1  0.537  0.081  0.333  1.0
  O  O39  1  0.463  0.581  0.167  1.0
[/CIF]
.
The structure described by CrP2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)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(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-47°. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-50°. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CrP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.235
_cell_length_b   8.047
_cell_length_c   9.359
_cell_angle_alpha   90.000
_cell_angle_beta   110.693
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   509.735
_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
  Cr  Cr0  1  0.273  0.492  0.747  1.0
  Cr  Cr1  1  0.273  0.008  0.247  1.0
  Cr  Cr2  1  0.727  0.992  0.753  1.0
  Cr  Cr3  1  0.727  0.508  0.253  1.0
  P  P4  1  0.073  0.239  0.944  1.0
  P  P5  1  0.073  0.261  0.444  1.0
  P  P6  1  0.927  0.739  0.556  1.0
  P  P7  1  0.927  0.761  0.056  1.0
  P  P8  1  0.325  0.798  0.551  1.0
  P  P9  1  0.675  0.298  0.949  1.0
  P  P10  1  0.325  0.702  0.051  1.0
  P  P11  1  0.675  0.202  0.449  1.0
  O  O12  1  0.009  0.586  0.657  1.0
  O  O13  1  0.009  0.914  0.157  1.0
  O  O14  1  0.991  0.086  0.843  1.0
  O  O15  1  0.991  0.414  0.343  1.0
  O  O16  1  0.200  0.354  0.892  1.0
  O  O17  1  0.200  0.146  0.392  1.0
  O  O18  1  0.800  0.854  0.608  1.0
  O  O19  1  0.800  0.646  0.108  1.0
  O  O20  1  0.110  0.850  0.551  1.0
  O  O21  1  0.110  0.650  0.051  1.0
  O  O22  1  0.890  0.350  0.949  1.0
  O  O23  1  0.890  0.150  0.449  1.0
  O  O24  1  0.326  0.679  0.889  1.0
  O  O25  1  0.326  0.821  0.389  1.0
  O  O26  1  0.674  0.179  0.611  1.0
  O  O27  1  0.674  0.321  0.111  1.0
  O  O28  1  0.191  0.311  0.610  1.0
  O  O29  1  0.191  0.189  0.110  1.0
  O  O30  1  0.809  0.811  0.890  1.0
  O  O31  1  0.809  0.689  0.390  1.0
  O  O32  1  0.360  0.617  0.601  1.0
  O  O33  1  0.640  0.117  0.899  1.0
  O  O34  1  0.360  0.883  0.101  1.0
  O  O35  1  0.640  0.383  0.399  1.0
  O  O36  1  0.537  0.419  0.833  1.0
  O  O37  1  0.463  0.919  0.667  1.0
  O  O38  1  0.537  0.081  0.333  1.0
  O  O39  1  0.463  0.581  0.167  1.0
[/CIF]
.