The structure described by NbP2O7 crystallizes in the cubic Pa-3 space group. Nb(1) is bonded to six equivalent O(1) atoms to form NbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(2) and three equivalent O(1) atoms to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 8°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Nb(1) and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent P(1) atoms. is represented by the CIF file [CIF]
data_NbP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.458
_cell_length_b   8.458
_cell_length_c   8.458
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   605.006
_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
  Nb  Nb0  1  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.000  0.500  0.500  1.0
  Nb  Nb2  1  0.500  0.000  0.500  1.0
  Nb  Nb3  1  0.500  0.500  0.000  1.0
  P  P4  1  0.108  0.608  0.892  1.0
  P  P5  1  0.108  0.892  0.392  1.0
  P  P6  1  0.392  0.392  0.392  1.0
  P  P7  1  0.392  0.108  0.892  1.0
  P  P8  1  0.608  0.608  0.608  1.0
  P  P9  1  0.608  0.892  0.108  1.0
  P  P10  1  0.892  0.108  0.608  1.0
  P  P11  1  0.892  0.392  0.108  1.0
  O  O12  1  0.059  0.722  0.423  1.0
  O  O13  1  0.077  0.941  0.222  1.0
  O  O14  1  0.278  0.923  0.441  1.0
  O  O15  1  0.500  0.000  0.000  1.0
  O  O16  1  0.559  0.778  0.577  1.0
  O  O17  1  0.559  0.722  0.077  1.0
  O  O18  1  0.577  0.559  0.778  1.0
  O  O19  1  0.577  0.941  0.278  1.0
  O  O20  1  0.722  0.423  0.059  1.0
  O  O21  1  0.778  0.577  0.559  1.0
  O  O22  1  0.778  0.923  0.059  1.0
  O  O23  1  0.923  0.441  0.278  1.0
  O  O24  1  0.941  0.222  0.077  1.0
  O  O25  1  0.000  0.500  0.000  1.0
  O  O26  1  0.059  0.778  0.923  1.0
  O  O27  1  0.077  0.559  0.722  1.0
  O  O28  1  0.222  0.077  0.941  1.0
  O  O29  1  0.222  0.423  0.441  1.0
  O  O30  1  0.278  0.577  0.941  1.0
  O  O31  1  0.423  0.059  0.722  1.0
  O  O32  1  0.423  0.441  0.222  1.0
  O  O33  1  0.441  0.278  0.923  1.0
  O  O34  1  0.441  0.222  0.423  1.0
  O  O35  1  0.500  0.500  0.500  1.0
  O  O36  1  0.722  0.077  0.559  1.0
  O  O37  1  0.923  0.059  0.778  1.0
  O  O38  1  0.941  0.278  0.577  1.0
  O  O39  1  0.000  0.000  0.500  1.0
[/CIF]
.
The structure described by NbP2O7 crystallizes in the cubic Pa-3 space group. Nb(1) is bonded to six equivalent O(1) atoms to form NbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(2) and three equivalent O(1) atoms to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 8°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Nb(1) and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent P(1) atoms. is represented by the CIF file [CIF]
data_NbP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.458
_cell_length_b   8.458
_cell_length_c   8.458
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   605.006
_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
  Nb  Nb0  1  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.000  0.500  0.500  1.0
  Nb  Nb2  1  0.500  0.000  0.500  1.0
  Nb  Nb3  1  0.500  0.500  0.000  1.0
  P  P4  1  0.108  0.608  0.892  1.0
  P  P5  1  0.108  0.892  0.392  1.0
  P  P6  1  0.392  0.392  0.392  1.0
  P  P7  1  0.392  0.108  0.892  1.0
  P  P8  1  0.608  0.608  0.608  1.0
  P  P9  1  0.608  0.892  0.108  1.0
  P  P10  1  0.892  0.108  0.608  1.0
  P  P11  1  0.892  0.392  0.108  1.0
  O  O12  1  0.059  0.722  0.423  1.0
  O  O13  1  0.077  0.941  0.222  1.0
  O  O14  1  0.278  0.923  0.441  1.0
  O  O15  1  0.500  0.000  0.000  1.0
  O  O16  1  0.559  0.778  0.577  1.0
  O  O17  1  0.559  0.722  0.077  1.0
  O  O18  1  0.577  0.559  0.778  1.0
  O  O19  1  0.577  0.941  0.278  1.0
  O  O20  1  0.722  0.423  0.059  1.0
  O  O21  1  0.778  0.577  0.559  1.0
  O  O22  1  0.778  0.923  0.059  1.0
  O  O23  1  0.923  0.441  0.278  1.0
  O  O24  1  0.941  0.222  0.077  1.0
  O  O25  1  0.000  0.500  0.000  1.0
  O  O26  1  0.059  0.778  0.923  1.0
  O  O27  1  0.077  0.559  0.722  1.0
  O  O28  1  0.222  0.077  0.941  1.0
  O  O29  1  0.222  0.423  0.441  1.0
  O  O30  1  0.278  0.577  0.941  1.0
  O  O31  1  0.423  0.059  0.722  1.0
  O  O32  1  0.423  0.441  0.222  1.0
  O  O33  1  0.441  0.278  0.923  1.0
  O  O34  1  0.441  0.222  0.423  1.0
  O  O35  1  0.500  0.500  0.500  1.0
  O  O36  1  0.722  0.077  0.559  1.0
  O  O37  1  0.923  0.059  0.778  1.0
  O  O38  1  0.941  0.278  0.577  1.0
  O  O39  1  0.000  0.000  0.500  1.0
[/CIF]
.