The compound described by Na2Fe7(PO4)6 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(11), one O(5), one O(9), and two equivalent O(3) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(2), one O(6), and two equivalent O(4) atoms to form FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(11), one O(12), one O(5), one O(6), one O(7), and one O(8) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(2), one O(3), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, and corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-61°. In the second P site, P(2) is bonded to one O(1), one O(12), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, and corners with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-59°. In the third P site, P(3) is bonded to one O(10), one O(5), one O(6), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-71°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one P(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Fe(2), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Fe(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Fe(1), one Fe(3), and one P(3) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), one Fe(2), one Fe(3), and one P(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Fe(3), one Fe(4), and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one P(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), one Fe(3), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Fe(2), one Fe(3), and one P(2) atom. is represented by the CIF file [CIF]
data_Na2Fe7(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.566
_cell_length_b   8.525
_cell_length_c   8.771
_cell_angle_alpha   92.873
_cell_angle_beta   107.357
_cell_angle_gamma   106.080
_symmetry_Int_Tables_number   1
_cell_volume   445.491
_cell_formula_units_Z   1
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  0.249  0.980  0.022  1.0
  Na  Na1  1  0.751  0.020  0.978  1.0
  Fe  Fe2  1  0.630  0.059  0.385  1.0
  Fe  Fe3  1  0.871  0.620  0.943  1.0
  Fe  Fe4  1  0.370  0.941  0.615  1.0
  Fe  Fe5  1  0.129  0.380  0.057  1.0
  Fe  Fe6  1  0.748  0.729  0.272  1.0
  Fe  Fe7  1  0.252  0.271  0.728  1.0
  Fe  Fe8  1  0.000  0.500  0.500  1.0
  P  P9  1  0.116  0.129  0.341  1.0
  P  P10  1  0.369  0.659  0.872  1.0
  P  P11  1  0.884  0.871  0.659  1.0
  P  P12  1  0.631  0.341  0.128  1.0
  P  P13  1  0.246  0.702  0.292  1.0
  P  P14  1  0.754  0.298  0.708  1.0
  O  O15  1  0.612  0.166  0.174  1.0
  O  O16  1  0.893  0.831  0.831  1.0
  O  O17  1  0.388  0.834  0.826  1.0
  O  O18  1  0.107  0.169  0.169  1.0
  O  O19  1  0.688  0.949  0.598  1.0
  O  O20  1  0.808  0.390  0.040  1.0
  O  O21  1  0.312  0.051  0.402  1.0
  O  O22  1  0.192  0.610  0.960  1.0
  O  O23  1  0.461  0.821  0.271  1.0
  O  O24  1  0.036  0.740  0.178  1.0
  O  O25  1  0.539  0.179  0.729  1.0
  O  O26  1  0.964  0.260  0.822  1.0
  O  O27  1  0.710  0.474  0.280  1.0
  O  O28  1  0.852  0.724  0.536  1.0
  O  O29  1  0.290  0.526  0.720  1.0
  O  O30  1  0.148  0.276  0.464  1.0
  O  O31  1  0.767  0.275  0.534  1.0
  O  O32  1  0.754  0.475  0.737  1.0
  O  O33  1  0.233  0.725  0.466  1.0
  O  O34  1  0.246  0.525  0.263  1.0
  O  O35  1  0.889  0.991  0.322  1.0
  O  O36  1  0.601  0.667  0.994  1.0
  O  O37  1  0.111  0.009  0.678  1.0
  O  O38  1  0.399  0.333  0.006  1.0
[/CIF]
.
The compound described by Na2Fe7(PO4)6 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(11), one O(5), one O(9), and two equivalent O(3) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(2), one O(6), and two equivalent O(4) atoms to form FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(11), one O(12), one O(5), one O(6), one O(7), and one O(8) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(2), one O(3), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, and corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-61°. In the second P site, P(2) is bonded to one O(1), one O(12), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, and corners with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-59°. In the third P site, P(3) is bonded to one O(10), one O(5), one O(6), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-71°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one P(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Fe(2), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Fe(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Fe(1), one Fe(3), and one P(3) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), one Fe(2), one Fe(3), and one P(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Fe(3), one Fe(4), and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one P(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), one Fe(3), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Fe(2), one Fe(3), and one P(2) atom. is represented by the CIF file [CIF]
data_Na2Fe7(PO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.566
_cell_length_b   8.525
_cell_length_c   8.771
_cell_angle_alpha   92.873
_cell_angle_beta   107.357
_cell_angle_gamma   106.080
_symmetry_Int_Tables_number   1
_cell_volume   445.491
_cell_formula_units_Z   1
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  0.249  0.980  0.022  1.0
  Na  Na1  1  0.751  0.020  0.978  1.0
  Fe  Fe2  1  0.630  0.059  0.385  1.0
  Fe  Fe3  1  0.871  0.620  0.943  1.0
  Fe  Fe4  1  0.370  0.941  0.615  1.0
  Fe  Fe5  1  0.129  0.380  0.057  1.0
  Fe  Fe6  1  0.748  0.729  0.272  1.0
  Fe  Fe7  1  0.252  0.271  0.728  1.0
  Fe  Fe8  1  0.000  0.500  0.500  1.0
  P  P9  1  0.116  0.129  0.341  1.0
  P  P10  1  0.369  0.659  0.872  1.0
  P  P11  1  0.884  0.871  0.659  1.0
  P  P12  1  0.631  0.341  0.128  1.0
  P  P13  1  0.246  0.702  0.292  1.0
  P  P14  1  0.754  0.298  0.708  1.0
  O  O15  1  0.612  0.166  0.174  1.0
  O  O16  1  0.893  0.831  0.831  1.0
  O  O17  1  0.388  0.834  0.826  1.0
  O  O18  1  0.107  0.169  0.169  1.0
  O  O19  1  0.688  0.949  0.598  1.0
  O  O20  1  0.808  0.390  0.040  1.0
  O  O21  1  0.312  0.051  0.402  1.0
  O  O22  1  0.192  0.610  0.960  1.0
  O  O23  1  0.461  0.821  0.271  1.0
  O  O24  1  0.036  0.740  0.178  1.0
  O  O25  1  0.539  0.179  0.729  1.0
  O  O26  1  0.964  0.260  0.822  1.0
  O  O27  1  0.710  0.474  0.280  1.0
  O  O28  1  0.852  0.724  0.536  1.0
  O  O29  1  0.290  0.526  0.720  1.0
  O  O30  1  0.148  0.276  0.464  1.0
  O  O31  1  0.767  0.275  0.534  1.0
  O  O32  1  0.754  0.475  0.737  1.0
  O  O33  1  0.233  0.725  0.466  1.0
  O  O34  1  0.246  0.525  0.263  1.0
  O  O35  1  0.889  0.991  0.322  1.0
  O  O36  1  0.601  0.667  0.994  1.0
  O  O37  1  0.111  0.009  0.678  1.0
  O  O38  1  0.399  0.333  0.006  1.0
[/CIF]
.