The crystal structure described by NaFeP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form FeO6 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 Fe(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-53°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-50°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Na(1), one P(1), and one P(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one Fe(1), and one P(2) atom. In the third O site, O(7) is bonded in a distorted trigonal planar geometry to one Na(1), one Fe(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the fifth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. is represented by the CIF card [CIF]
data_NaFeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.040
_cell_length_b   7.424
_cell_length_c   9.692
_cell_angle_alpha   68.284
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   537.466
_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
  Na  Na0  1  0.524  0.712  0.291  1.0
  Na  Na1  1  0.024  0.288  0.209  1.0
  Na  Na2  1  0.976  0.712  0.791  1.0
  Na  Na3  1  0.476  0.288  0.709  1.0
  Fe  Fe4  1  0.991  0.741  0.250  1.0
  Fe  Fe5  1  0.491  0.259  0.250  1.0
  Fe  Fe6  1  0.009  0.259  0.750  1.0
  Fe  Fe7  1  0.509  0.741  0.750  1.0
  P  P8  1  0.788  0.328  0.453  1.0
  P  P9  1  0.755  0.928  0.954  1.0
  P  P10  1  0.245  0.072  0.046  1.0
  P  P11  1  0.745  0.928  0.454  1.0
  P  P12  1  0.712  0.328  0.953  1.0
  P  P13  1  0.212  0.672  0.547  1.0
  P  P14  1  0.255  0.072  0.546  1.0
  P  P15  1  0.288  0.672  0.047  1.0
  O  O16  1  0.892  0.365  0.897  1.0
  O  O17  1  0.392  0.635  0.603  1.0
  O  O18  1  0.108  0.635  0.103  1.0
  O  O19  1  0.608  0.365  0.397  1.0
  O  O20  1  0.700  0.309  0.115  1.0
  O  O21  1  0.200  0.691  0.385  1.0
  O  O22  1  0.300  0.691  0.885  1.0
  O  O23  1  0.800  0.309  0.615  1.0
  O  O24  1  0.587  0.467  0.848  1.0
  O  O25  1  0.087  0.533  0.652  1.0
  O  O26  1  0.413  0.533  0.152  1.0
  O  O27  1  0.913  0.467  0.348  1.0
  O  O28  1  0.636  0.819  0.892  1.0
  O  O29  1  0.136  0.181  0.608  1.0
  O  O30  1  0.364  0.181  0.108  1.0
  O  O31  1  0.864  0.819  0.392  1.0
  O  O32  1  0.846  0.124  0.438  1.0
  O  O33  1  0.346  0.876  0.062  1.0
  O  O34  1  0.154  0.876  0.562  1.0
  O  O35  1  0.654  0.124  0.938  1.0
  O  O36  1  0.714  0.815  0.620  1.0
  O  O37  1  0.214  0.185  0.880  1.0
  O  O38  1  0.286  0.185  0.380  1.0
  O  O39  1  0.786  0.815  0.120  1.0
  O  O40  1  0.585  0.989  0.361  1.0
  O  O41  1  0.085  0.011  0.139  1.0
  O  O42  1  0.415  0.011  0.639  1.0
  O  O43  1  0.915  0.989  0.861  1.0
[/CIF]
.
The crystal structure described by NaFeP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form FeO6 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 Fe(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-53°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-50°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Na(1), one P(1), and one P(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one Fe(1), and one P(2) atom. In the third O site, O(7) is bonded in a distorted trigonal planar geometry to one Na(1), one Fe(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the fifth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. is represented by the CIF card [CIF]
data_NaFeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.040
_cell_length_b   7.424
_cell_length_c   9.692
_cell_angle_alpha   68.284
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   537.466
_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
  Na  Na0  1  0.524  0.712  0.291  1.0
  Na  Na1  1  0.024  0.288  0.209  1.0
  Na  Na2  1  0.976  0.712  0.791  1.0
  Na  Na3  1  0.476  0.288  0.709  1.0
  Fe  Fe4  1  0.991  0.741  0.250  1.0
  Fe  Fe5  1  0.491  0.259  0.250  1.0
  Fe  Fe6  1  0.009  0.259  0.750  1.0
  Fe  Fe7  1  0.509  0.741  0.750  1.0
  P  P8  1  0.788  0.328  0.453  1.0
  P  P9  1  0.755  0.928  0.954  1.0
  P  P10  1  0.245  0.072  0.046  1.0
  P  P11  1  0.745  0.928  0.454  1.0
  P  P12  1  0.712  0.328  0.953  1.0
  P  P13  1  0.212  0.672  0.547  1.0
  P  P14  1  0.255  0.072  0.546  1.0
  P  P15  1  0.288  0.672  0.047  1.0
  O  O16  1  0.892  0.365  0.897  1.0
  O  O17  1  0.392  0.635  0.603  1.0
  O  O18  1  0.108  0.635  0.103  1.0
  O  O19  1  0.608  0.365  0.397  1.0
  O  O20  1  0.700  0.309  0.115  1.0
  O  O21  1  0.200  0.691  0.385  1.0
  O  O22  1  0.300  0.691  0.885  1.0
  O  O23  1  0.800  0.309  0.615  1.0
  O  O24  1  0.587  0.467  0.848  1.0
  O  O25  1  0.087  0.533  0.652  1.0
  O  O26  1  0.413  0.533  0.152  1.0
  O  O27  1  0.913  0.467  0.348  1.0
  O  O28  1  0.636  0.819  0.892  1.0
  O  O29  1  0.136  0.181  0.608  1.0
  O  O30  1  0.364  0.181  0.108  1.0
  O  O31  1  0.864  0.819  0.392  1.0
  O  O32  1  0.846  0.124  0.438  1.0
  O  O33  1  0.346  0.876  0.062  1.0
  O  O34  1  0.154  0.876  0.562  1.0
  O  O35  1  0.654  0.124  0.938  1.0
  O  O36  1  0.714  0.815  0.620  1.0
  O  O37  1  0.214  0.185  0.880  1.0
  O  O38  1  0.286  0.185  0.380  1.0
  O  O39  1  0.786  0.815  0.120  1.0
  O  O40  1  0.585  0.989  0.361  1.0
  O  O41  1  0.085  0.011  0.139  1.0
  O  O42  1  0.415  0.011  0.639  1.0
  O  O43  1  0.915  0.989  0.861  1.0
[/CIF]
.