The material described by CrP2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Cr(1)O6 octahedra. 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(7) 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 37-56°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) 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 13-45°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one P(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Cr(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the seventh O site, O(7) 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   7.052
_cell_length_b   8.197
_cell_length_c   8.832
_cell_angle_alpha   90.000
_cell_angle_beta   111.773
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   474.116
_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  0.377  0.086  0.613  1.0
  Cr  Cr1  1  0.623  0.914  0.387  1.0
  Cr  Cr2  1  0.123  0.586  0.887  1.0
  Cr  Cr3  1  0.877  0.414  0.113  1.0
  P  P4  1  0.178  0.730  0.247  1.0
  P  P5  1  0.424  0.240  0.961  1.0
  P  P6  1  0.678  0.770  0.747  1.0
  P  P7  1  0.924  0.260  0.461  1.0
  P  P8  1  0.322  0.230  0.253  1.0
  P  P9  1  0.076  0.740  0.539  1.0
  P  P10  1  0.576  0.760  0.039  1.0
  P  P11  1  0.822  0.270  0.753  1.0
  O  O12  1  0.371  0.156  0.105  1.0
  O  O13  1  0.564  0.615  0.680  1.0
  O  O14  1  0.064  0.885  0.180  1.0
  O  O15  1  0.307  0.400  0.917  1.0
  O  O16  1  0.629  0.844  0.895  1.0
  O  O17  1  0.392  0.083  0.377  1.0
  O  O18  1  0.693  0.600  0.083  1.0
  O  O19  1  0.363  0.109  0.830  1.0
  O  O20  1  0.156  0.234  0.528  1.0
  O  O21  1  0.608  0.917  0.623  1.0
  O  O22  1  0.892  0.417  0.877  1.0
  O  O23  1  0.910  0.748  0.811  1.0
  O  O24  1  0.590  0.248  0.689  1.0
  O  O25  1  0.871  0.344  0.605  1.0
  O  O26  1  0.108  0.583  0.123  1.0
  O  O27  1  0.936  0.115  0.820  1.0
  O  O28  1  0.090  0.252  0.189  1.0
  O  O29  1  0.637  0.891  0.170  1.0
  O  O30  1  0.656  0.266  0.028  1.0
  O  O31  1  0.344  0.734  0.972  1.0
  O  O32  1  0.193  0.900  0.583  1.0
  O  O33  1  0.863  0.391  0.330  1.0
  O  O34  1  0.137  0.609  0.670  1.0
  O  O35  1  0.436  0.385  0.320  1.0
  O  O36  1  0.410  0.752  0.311  1.0
  O  O37  1  0.807  0.100  0.417  1.0
  O  O38  1  0.844  0.766  0.472  1.0
  O  O39  1  0.129  0.656  0.395  1.0
[/CIF]
.
The material described by CrP2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Cr(1)O6 octahedra. 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(7) 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 37-56°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) 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 13-45°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one P(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Cr(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the seventh O site, O(7) 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   7.052
_cell_length_b   8.197
_cell_length_c   8.832
_cell_angle_alpha   90.000
_cell_angle_beta   111.773
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   474.116
_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  0.377  0.086  0.613  1.0
  Cr  Cr1  1  0.623  0.914  0.387  1.0
  Cr  Cr2  1  0.123  0.586  0.887  1.0
  Cr  Cr3  1  0.877  0.414  0.113  1.0
  P  P4  1  0.178  0.730  0.247  1.0
  P  P5  1  0.424  0.240  0.961  1.0
  P  P6  1  0.678  0.770  0.747  1.0
  P  P7  1  0.924  0.260  0.461  1.0
  P  P8  1  0.322  0.230  0.253  1.0
  P  P9  1  0.076  0.740  0.539  1.0
  P  P10  1  0.576  0.760  0.039  1.0
  P  P11  1  0.822  0.270  0.753  1.0
  O  O12  1  0.371  0.156  0.105  1.0
  O  O13  1  0.564  0.615  0.680  1.0
  O  O14  1  0.064  0.885  0.180  1.0
  O  O15  1  0.307  0.400  0.917  1.0
  O  O16  1  0.629  0.844  0.895  1.0
  O  O17  1  0.392  0.083  0.377  1.0
  O  O18  1  0.693  0.600  0.083  1.0
  O  O19  1  0.363  0.109  0.830  1.0
  O  O20  1  0.156  0.234  0.528  1.0
  O  O21  1  0.608  0.917  0.623  1.0
  O  O22  1  0.892  0.417  0.877  1.0
  O  O23  1  0.910  0.748  0.811  1.0
  O  O24  1  0.590  0.248  0.689  1.0
  O  O25  1  0.871  0.344  0.605  1.0
  O  O26  1  0.108  0.583  0.123  1.0
  O  O27  1  0.936  0.115  0.820  1.0
  O  O28  1  0.090  0.252  0.189  1.0
  O  O29  1  0.637  0.891  0.170  1.0
  O  O30  1  0.656  0.266  0.028  1.0
  O  O31  1  0.344  0.734  0.972  1.0
  O  O32  1  0.193  0.900  0.583  1.0
  O  O33  1  0.863  0.391  0.330  1.0
  O  O34  1  0.137  0.609  0.670  1.0
  O  O35  1  0.436  0.385  0.320  1.0
  O  O36  1  0.410  0.752  0.311  1.0
  O  O37  1  0.807  0.100  0.417  1.0
  O  O38  1  0.844  0.766  0.472  1.0
  O  O39  1  0.129  0.656  0.395  1.0
[/CIF]
.