The structure described by Na2Fe2Zn(PO4)3 is Esseneite-derived structured and crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(6), and four equivalent O(5) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(2) atoms. Fe(1) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Zn(1)O6 octahedra. Zn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted ZnO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-61°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-58°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(2), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(2), one Zn(1), and one P(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Fe(1), one Zn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), one Zn(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Na2ZnFe2(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.675
_cell_length_b   8.675
_cell_length_c   6.587
_cell_angle_alpha   73.882
_cell_angle_beta   73.882
_cell_angle_gamma   93.439
_symmetry_Int_Tables_number   1
_cell_volume   452.399
_cell_formula_units_Z   2
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  0.986  0.014  0.250  1.0
  Na  Na1  1  0.014  0.986  0.750  1.0
  Na  Na2  1  0.500  0.500  0.000  1.0
  Na  Na3  1  0.500  0.500  0.500  1.0
  Zn  Zn4  1  0.269  0.731  0.250  1.0
  Zn  Zn5  1  0.731  0.269  0.750  1.0
  Fe  Fe6  1  0.381  0.057  0.374  1.0
  Fe  Fe7  1  0.619  0.943  0.626  1.0
  Fe  Fe8  1  0.943  0.619  0.126  1.0
  Fe  Fe9  1  0.057  0.381  0.874  1.0
  P  P10  1  0.711  0.289  0.250  1.0
  P  P11  1  0.289  0.711  0.750  1.0
  P  P12  1  0.656  0.874  0.119  1.0
  P  P13  1  0.344  0.126  0.881  1.0
  P  P14  1  0.126  0.344  0.381  1.0
  P  P15  1  0.874  0.656  0.619  1.0
  O  O16  1  0.533  0.262  0.253  1.0
  O  O17  1  0.467  0.738  0.747  1.0
  O  O18  1  0.738  0.467  0.247  1.0
  O  O19  1  0.262  0.533  0.753  1.0
  O  O20  1  0.524  0.729  0.169  1.0
  O  O21  1  0.476  0.271  0.831  1.0
  O  O22  1  0.271  0.476  0.331  1.0
  O  O23  1  0.729  0.524  0.669  1.0
  O  O24  1  0.742  0.177  0.462  1.0
  O  O25  1  0.258  0.823  0.538  1.0
  O  O26  1  0.823  0.258  0.038  1.0
  O  O27  1  0.177  0.742  0.962  1.0
  O  O28  1  0.604  0.955  0.308  1.0
  O  O29  1  0.396  0.045  0.692  1.0
  O  O30  1  0.045  0.396  0.192  1.0
  O  O31  1  0.955  0.604  0.808  1.0
  O  O32  1  0.827  0.825  0.108  1.0
  O  O33  1  0.173  0.175  0.892  1.0
  O  O34  1  0.175  0.173  0.392  1.0
  O  O35  1  0.825  0.827  0.608  1.0
  O  O36  1  0.324  0.996  0.110  1.0
  O  O37  1  0.676  0.004  0.890  1.0
  O  O38  1  0.004  0.676  0.390  1.0
  O  O39  1  0.996  0.324  0.610  1.0
[/CIF]
.
The structure described by Na2Fe2Zn(PO4)3 is Esseneite-derived structured and crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(6), and four equivalent O(5) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(2) atoms. Fe(1) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Zn(1)O6 octahedra. Zn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted ZnO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-61°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-58°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(2), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(2), one Zn(1), and one P(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Fe(1), one Zn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), one Zn(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Na2ZnFe2(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.675
_cell_length_b   8.675
_cell_length_c   6.587
_cell_angle_alpha   73.882
_cell_angle_beta   73.882
_cell_angle_gamma   93.439
_symmetry_Int_Tables_number   1
_cell_volume   452.399
_cell_formula_units_Z   2
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  0.986  0.014  0.250  1.0
  Na  Na1  1  0.014  0.986  0.750  1.0
  Na  Na2  1  0.500  0.500  0.000  1.0
  Na  Na3  1  0.500  0.500  0.500  1.0
  Zn  Zn4  1  0.269  0.731  0.250  1.0
  Zn  Zn5  1  0.731  0.269  0.750  1.0
  Fe  Fe6  1  0.381  0.057  0.374  1.0
  Fe  Fe7  1  0.619  0.943  0.626  1.0
  Fe  Fe8  1  0.943  0.619  0.126  1.0
  Fe  Fe9  1  0.057  0.381  0.874  1.0
  P  P10  1  0.711  0.289  0.250  1.0
  P  P11  1  0.289  0.711  0.750  1.0
  P  P12  1  0.656  0.874  0.119  1.0
  P  P13  1  0.344  0.126  0.881  1.0
  P  P14  1  0.126  0.344  0.381  1.0
  P  P15  1  0.874  0.656  0.619  1.0
  O  O16  1  0.533  0.262  0.253  1.0
  O  O17  1  0.467  0.738  0.747  1.0
  O  O18  1  0.738  0.467  0.247  1.0
  O  O19  1  0.262  0.533  0.753  1.0
  O  O20  1  0.524  0.729  0.169  1.0
  O  O21  1  0.476  0.271  0.831  1.0
  O  O22  1  0.271  0.476  0.331  1.0
  O  O23  1  0.729  0.524  0.669  1.0
  O  O24  1  0.742  0.177  0.462  1.0
  O  O25  1  0.258  0.823  0.538  1.0
  O  O26  1  0.823  0.258  0.038  1.0
  O  O27  1  0.177  0.742  0.962  1.0
  O  O28  1  0.604  0.955  0.308  1.0
  O  O29  1  0.396  0.045  0.692  1.0
  O  O30  1  0.045  0.396  0.192  1.0
  O  O31  1  0.955  0.604  0.808  1.0
  O  O32  1  0.827  0.825  0.108  1.0
  O  O33  1  0.173  0.175  0.892  1.0
  O  O34  1  0.175  0.173  0.392  1.0
  O  O35  1  0.825  0.827  0.608  1.0
  O  O36  1  0.324  0.996  0.110  1.0
  O  O37  1  0.676  0.004  0.890  1.0
  O  O38  1  0.004  0.676  0.390  1.0
  O  O39  1  0.996  0.324  0.610  1.0
[/CIF]
.