The material structure described by Na2FeCPO7 crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(8), and one O(9) atom. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(5), and one O(7) atom. In the third Na site, Na(3) is bonded to one O(1), one O(11), one O(14), one O(4), one O(5), one O(7), and one O(9) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Na(4)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 67°. In the fourth Na site, Na(4) is bonded to one O(10), one O(11), one O(13), one O(2), one O(4), one O(5), and one O(8) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one P(2)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Na(3)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 63°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(12), one O(14), one O(3), one O(5), and one O(9) atom to form distorted FeO6 octahedra that share  a cornercorner with one Na(3)O7 pentagonal bipyramid, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Na(3)O7 pentagonal bipyramid, and  an edgeedge with one Na(4)O7 pentagonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(11), one O(13), one O(4), one O(6), one O(7), and one O(8) atom to form distorted FeO6 octahedra that share  a cornercorner with one Na(4)O7 pentagonal bipyramid, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a faceface with one Na(3)O7 pentagonal bipyramid, and  a faceface with one Na(4)O7 pentagonal bipyramid. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(14), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Na(3)O7 pentagonal bipyramid, corners with two equivalent Na(4)O7 pentagonal bipyramids, and  an edgeedge with one Na(3)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 35-43°. In the second P site, P(2) is bonded to one O(10), one O(12), one O(13), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Na(3)O7 pentagonal bipyramid, and  an edgeedge with one Na(4)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 33-48°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(3), and one C(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(4), and one C(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), one Fe(2), and one C(2) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), one Fe(1), and one C(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(2), and one C(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Fe(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(1), one Na(4), one Fe(2), and one P(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Fe(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Na(2), one Na(4), one Fe(1), and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Na(3), one Na(4), one Fe(2), and one P(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Na(4), one Fe(2), and one P(2) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Na(3), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Na2FePCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.343
_cell_length_b   8.356
_cell_length_c   10.353
_cell_angle_alpha   108.051
_cell_angle_beta   108.082
_cell_angle_gamma   102.509
_symmetry_Int_Tables_number   1
_cell_volume   612.032
_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  0.461  0.706  0.928  1.0
  Na  Na1  1  0.946  0.200  0.913  1.0
  Na  Na2  1  0.728  0.748  0.732  1.0
  Na  Na3  1  1.000  0.482  0.733  1.0
  Na  Na4  1  0.000  0.518  0.267  1.0
  Na  Na5  1  0.272  0.252  0.268  1.0
  Na  Na6  1  0.539  0.294  0.072  1.0
  Na  Na7  1  0.054  0.800  0.087  1.0
  Fe  Fe8  1  0.549  0.300  0.657  1.0
  Fe  Fe9  1  0.071  0.822  0.654  1.0
  Fe  Fe10  1  0.929  0.178  0.346  1.0
  Fe  Fe11  1  0.451  0.700  0.343  1.0
  P  P12  1  0.308  0.557  0.574  1.0
  P  P13  1  0.809  0.061  0.578  1.0
  P  P14  1  0.692  0.443  0.426  1.0
  P  P15  1  0.191  0.939  0.422  1.0
  C  C16  1  0.736  0.482  0.936  1.0
  C  C17  1  0.221  0.975  0.935  1.0
  C  C18  1  0.779  0.025  0.065  1.0
  C  C19  1  0.264  0.518  0.064  1.0
  O  O20  1  0.702  0.937  0.926  1.0
  O  O21  1  0.176  0.441  0.923  1.0
  O  O22  1  0.590  0.340  0.874  1.0
  O  O23  1  0.078  0.827  0.870  1.0
  O  O24  1  0.786  0.537  0.844  1.0
  O  O25  1  0.277  0.024  0.843  1.0
  O  O26  1  0.915  0.978  0.676  1.0
  O  O27  1  0.226  0.664  0.671  1.0
  O  O28  1  0.431  0.491  0.676  1.0
  O  O29  1  0.742  0.183  0.679  1.0
  O  O30  1  0.843  0.598  0.570  1.0
  O  O31  1  0.342  0.086  0.566  1.0
  O  O32  1  0.936  0.184  0.537  1.0
  O  O33  1  0.427  0.678  0.526  1.0
  O  O34  1  0.064  0.816  0.463  1.0
  O  O35  1  0.573  0.322  0.474  1.0
  O  O36  1  0.658  0.914  0.434  1.0
  O  O37  1  0.157  0.402  0.430  1.0
  O  O38  1  0.258  0.817  0.321  1.0
  O  O39  1  0.569  0.509  0.324  1.0
  O  O40  1  0.774  0.336  0.329  1.0
  O  O41  1  0.085  0.022  0.324  1.0
  O  O42  1  0.723  0.976  0.157  1.0
  O  O43  1  0.214  0.463  0.156  1.0
  O  O44  1  0.922  0.173  0.130  1.0
  O  O45  1  0.410  0.660  0.126  1.0
  O  O46  1  0.824  0.559  0.077  1.0
  O  O47  1  0.298  0.063  0.074  1.0
[/CIF]
.
The material structure described by Na2FeCPO7 crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(8), and one O(9) atom. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(5), and one O(7) atom. In the third Na site, Na(3) is bonded to one O(1), one O(11), one O(14), one O(4), one O(5), one O(7), and one O(9) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Na(4)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 67°. In the fourth Na site, Na(4) is bonded to one O(10), one O(11), one O(13), one O(2), one O(4), one O(5), and one O(8) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one P(2)O4 tetrahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Na(3)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 63°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(12), one O(14), one O(3), one O(5), and one O(9) atom to form distorted FeO6 octahedra that share  a cornercorner with one Na(3)O7 pentagonal bipyramid, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Na(3)O7 pentagonal bipyramid, and  an edgeedge with one Na(4)O7 pentagonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(11), one O(13), one O(4), one O(6), one O(7), and one O(8) atom to form distorted FeO6 octahedra that share  a cornercorner with one Na(4)O7 pentagonal bipyramid, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a faceface with one Na(3)O7 pentagonal bipyramid, and  a faceface with one Na(4)O7 pentagonal bipyramid. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(14), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Na(3)O7 pentagonal bipyramid, corners with two equivalent Na(4)O7 pentagonal bipyramids, and  an edgeedge with one Na(3)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 35-43°. In the second P site, P(2) is bonded to one O(10), one O(12), one O(13), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Na(3)O7 pentagonal bipyramid, and  an edgeedge with one Na(4)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 33-48°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(3), and one C(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(4), and one C(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), one Fe(2), and one C(2) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), one Fe(1), and one C(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(2), and one C(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Fe(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(1), one Na(4), one Fe(2), and one P(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Fe(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Na(2), one Na(4), one Fe(1), and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Na(3), one Na(4), one Fe(2), and one P(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Na(4), one Fe(2), and one P(2) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Na(3), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Na2FePCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.343
_cell_length_b   8.356
_cell_length_c   10.353
_cell_angle_alpha   108.051
_cell_angle_beta   108.082
_cell_angle_gamma   102.509
_symmetry_Int_Tables_number   1
_cell_volume   612.032
_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  0.461  0.706  0.928  1.0
  Na  Na1  1  0.946  0.200  0.913  1.0
  Na  Na2  1  0.728  0.748  0.732  1.0
  Na  Na3  1  1.000  0.482  0.733  1.0
  Na  Na4  1  0.000  0.518  0.267  1.0
  Na  Na5  1  0.272  0.252  0.268  1.0
  Na  Na6  1  0.539  0.294  0.072  1.0
  Na  Na7  1  0.054  0.800  0.087  1.0
  Fe  Fe8  1  0.549  0.300  0.657  1.0
  Fe  Fe9  1  0.071  0.822  0.654  1.0
  Fe  Fe10  1  0.929  0.178  0.346  1.0
  Fe  Fe11  1  0.451  0.700  0.343  1.0
  P  P12  1  0.308  0.557  0.574  1.0
  P  P13  1  0.809  0.061  0.578  1.0
  P  P14  1  0.692  0.443  0.426  1.0
  P  P15  1  0.191  0.939  0.422  1.0
  C  C16  1  0.736  0.482  0.936  1.0
  C  C17  1  0.221  0.975  0.935  1.0
  C  C18  1  0.779  0.025  0.065  1.0
  C  C19  1  0.264  0.518  0.064  1.0
  O  O20  1  0.702  0.937  0.926  1.0
  O  O21  1  0.176  0.441  0.923  1.0
  O  O22  1  0.590  0.340  0.874  1.0
  O  O23  1  0.078  0.827  0.870  1.0
  O  O24  1  0.786  0.537  0.844  1.0
  O  O25  1  0.277  0.024  0.843  1.0
  O  O26  1  0.915  0.978  0.676  1.0
  O  O27  1  0.226  0.664  0.671  1.0
  O  O28  1  0.431  0.491  0.676  1.0
  O  O29  1  0.742  0.183  0.679  1.0
  O  O30  1  0.843  0.598  0.570  1.0
  O  O31  1  0.342  0.086  0.566  1.0
  O  O32  1  0.936  0.184  0.537  1.0
  O  O33  1  0.427  0.678  0.526  1.0
  O  O34  1  0.064  0.816  0.463  1.0
  O  O35  1  0.573  0.322  0.474  1.0
  O  O36  1  0.658  0.914  0.434  1.0
  O  O37  1  0.157  0.402  0.430  1.0
  O  O38  1  0.258  0.817  0.321  1.0
  O  O39  1  0.569  0.509  0.324  1.0
  O  O40  1  0.774  0.336  0.329  1.0
  O  O41  1  0.085  0.022  0.324  1.0
  O  O42  1  0.723  0.976  0.157  1.0
  O  O43  1  0.214  0.463  0.156  1.0
  O  O44  1  0.922  0.173  0.130  1.0
  O  O45  1  0.410  0.660  0.126  1.0
  O  O46  1  0.824  0.559  0.077  1.0
  O  O47  1  0.298  0.063  0.074  1.0
[/CIF]
.