The material structure described by NiP2O7 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form NiO6 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(4), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 39-52°. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-50°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(2) atom. is represented by the CIF card [CIF]
data_NiP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.195
_cell_length_b   7.255
_cell_length_c   9.343
_cell_angle_alpha   71.150
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   525.697
_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
  Ni  Ni0  1  0.994  0.230  0.248  1.0
  Ni  Ni1  1  0.506  0.230  0.748  1.0
  Ni  Ni2  1  0.006  0.770  0.752  1.0
  Ni  Ni3  1  0.494  0.770  0.252  1.0
  P  P4  1  0.698  0.829  0.938  1.0
  P  P5  1  0.198  0.171  0.562  1.0
  P  P6  1  0.802  0.829  0.438  1.0
  P  P7  1  0.263  0.568  0.561  1.0
  P  P8  1  0.237  0.568  0.061  1.0
  P  P9  1  0.737  0.432  0.439  1.0
  P  P10  1  0.302  0.171  0.062  1.0
  P  P11  1  0.763  0.432  0.939  1.0
  O  O12  1  0.415  0.037  0.182  1.0
  O  O13  1  0.380  0.143  0.600  1.0
  O  O14  1  0.321  0.660  0.398  1.0
  O  O15  1  0.620  0.857  0.400  1.0
  O  O16  1  0.331  0.159  0.904  1.0
  O  O17  1  0.179  0.660  0.898  1.0
  O  O18  1  0.404  0.492  0.673  1.0
  O  O19  1  0.148  0.386  0.563  1.0
  O  O20  1  0.904  0.508  0.827  1.0
  O  O21  1  0.679  0.340  0.602  1.0
  O  O22  1  0.880  0.857  0.900  1.0
  O  O23  1  0.596  0.508  0.327  1.0
  O  O24  1  0.169  0.159  0.404  1.0
  O  O25  1  0.669  0.841  0.096  1.0
  O  O26  1  0.096  0.492  0.173  1.0
  O  O27  1  0.654  0.286  0.901  1.0
  O  O28  1  0.346  0.714  0.099  1.0
  O  O29  1  0.846  0.286  0.401  1.0
  O  O30  1  0.154  0.714  0.599  1.0
  O  O31  1  0.915  0.963  0.318  1.0
  O  O32  1  0.352  0.386  0.063  1.0
  O  O33  1  0.120  0.143  0.100  1.0
  O  O34  1  0.831  0.841  0.596  1.0
  O  O35  1  0.585  0.963  0.818  1.0
  O  O36  1  0.648  0.614  0.937  1.0
  O  O37  1  0.085  0.037  0.682  1.0
  O  O38  1  0.852  0.614  0.437  1.0
  O  O39  1  0.821  0.340  0.102  1.0
[/CIF]
.
The material structure described by NiP2O7 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form NiO6 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(4), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 39-52°. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-50°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(2) atom. is represented by the CIF card [CIF]
data_NiP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.195
_cell_length_b   7.255
_cell_length_c   9.343
_cell_angle_alpha   71.150
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   525.697
_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
  Ni  Ni0  1  0.994  0.230  0.248  1.0
  Ni  Ni1  1  0.506  0.230  0.748  1.0
  Ni  Ni2  1  0.006  0.770  0.752  1.0
  Ni  Ni3  1  0.494  0.770  0.252  1.0
  P  P4  1  0.698  0.829  0.938  1.0
  P  P5  1  0.198  0.171  0.562  1.0
  P  P6  1  0.802  0.829  0.438  1.0
  P  P7  1  0.263  0.568  0.561  1.0
  P  P8  1  0.237  0.568  0.061  1.0
  P  P9  1  0.737  0.432  0.439  1.0
  P  P10  1  0.302  0.171  0.062  1.0
  P  P11  1  0.763  0.432  0.939  1.0
  O  O12  1  0.415  0.037  0.182  1.0
  O  O13  1  0.380  0.143  0.600  1.0
  O  O14  1  0.321  0.660  0.398  1.0
  O  O15  1  0.620  0.857  0.400  1.0
  O  O16  1  0.331  0.159  0.904  1.0
  O  O17  1  0.179  0.660  0.898  1.0
  O  O18  1  0.404  0.492  0.673  1.0
  O  O19  1  0.148  0.386  0.563  1.0
  O  O20  1  0.904  0.508  0.827  1.0
  O  O21  1  0.679  0.340  0.602  1.0
  O  O22  1  0.880  0.857  0.900  1.0
  O  O23  1  0.596  0.508  0.327  1.0
  O  O24  1  0.169  0.159  0.404  1.0
  O  O25  1  0.669  0.841  0.096  1.0
  O  O26  1  0.096  0.492  0.173  1.0
  O  O27  1  0.654  0.286  0.901  1.0
  O  O28  1  0.346  0.714  0.099  1.0
  O  O29  1  0.846  0.286  0.401  1.0
  O  O30  1  0.154  0.714  0.599  1.0
  O  O31  1  0.915  0.963  0.318  1.0
  O  O32  1  0.352  0.386  0.063  1.0
  O  O33  1  0.120  0.143  0.100  1.0
  O  O34  1  0.831  0.841  0.596  1.0
  O  O35  1  0.585  0.963  0.818  1.0
  O  O36  1  0.648  0.614  0.937  1.0
  O  O37  1  0.085  0.037  0.682  1.0
  O  O38  1  0.852  0.614  0.437  1.0
  O  O39  1  0.821  0.340  0.102  1.0
[/CIF]
.