The material structure described by Fe2O(PO4)2 crystallizes in the triclinic P1 space group. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(13), one O(17), one O(24), one O(27), one O(29), and one O(32) atom to form FeO6 octahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the second Fe site, Fe(2) is bonded to one O(14), one O(18), one O(23), one O(28), one O(31), and one O(35) atom to form FeO6 octahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(8)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the third Fe site, Fe(3) is bonded to one O(15), one O(19), one O(22), one O(25), one O(30), and one O(34) atom to form FeO6 octahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one P(7)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the fourth Fe site, Fe(4) is bonded to one O(16), one O(20), one O(21), one O(26), one O(33), and one O(36) atom to form FeO6 octahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the fifth Fe site, Fe(5) is bonded to one O(11), one O(12), one O(13), one O(14), one O(4), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and edges with two equivalent Fe(8)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(15), one O(16), one O(2), one O(6), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(8)O4 tetrahedra, and edges with two equivalent Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the seventh Fe site, Fe(7) is bonded to one O(1), one O(10), one O(15), one O(16), one O(5), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(8)O4 tetrahedra, and edges with two equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the eighth Fe site, Fe(8) is bonded to one O(11), one O(12), one O(13), one O(14), one O(3), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and edges with two equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are eight inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(24), one O(27), and one O(35) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-52°. In the second P site, P(2) is bonded to one O(11), one O(23), one O(28), and one O(29) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-52°. In the third P site, P(3) is bonded to one O(10), one O(22), one O(25), and one O(33) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-52°. In the fourth P site, P(4) is bonded to one O(21), one O(26), one O(34), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and corners with two equivalent Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-52°. In the fifth P site, P(5) is bonded to one O(17), one O(2), one O(32), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the sixth P site, P(6) is bonded to one O(20), one O(3), one O(36), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the seventh P site, P(7) is bonded to one O(19), one O(30), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the eighth P site, P(8) is bonded to one O(1), one O(18), one O(31), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are thirty-six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Fe(7) and one P(8) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Fe(6) and one P(5) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Fe(8) and one P(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Fe(5) and one P(7) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Fe(7) and one P(5) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Fe(6) and one P(8) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Fe(8) and one P(7) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Fe(5) and one P(6) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(6), one Fe(7), and one P(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(6), one Fe(7), and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Fe(5), one Fe(8), and one P(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Fe(5), one Fe(8), and one P(1) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Fe(2), one Fe(5), and one Fe(8) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(7) atom. In the sixteenth O site, O(16) is bonded in a trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the seventeenth O site, O(17) is bonded in an L-shaped geometry to one Fe(1) and one P(5) atom. In the eighteenth O site, O(18) is bonded in an L-shaped geometry to one Fe(2) and one P(8) atom. In the nineteenth O site, O(19) is bonded in an L-shaped geometry to one Fe(3) and one P(7) atom. In the twentieth O site, O(20) is bonded in an L-shaped geometry to one Fe(4) and one P(6) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one Fe(4) and one P(4) atom. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(3) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the twenty-fourth O site, O(24) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(3) atom. In the twenty-sixth O site, O(26) is bonded in a bent 150 degrees geometry to one Fe(4) and one P(4) atom. In the twenty-seventh O site, O(27) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the twenty-eighth O site, O(28) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the twenty-ninth O site, O(29) is bonded in a linear geometry to one Fe(1) and one P(2) atom. In the thirtieth O site, O(30) is bonded in an L-shaped geometry to one Fe(3) and one P(7) atom. In the thirty-first O site, O(31) is bonded in an L-shaped geometry to one Fe(2) and one P(8) atom. In the thirty-second O site, O(32) is bonded in an L-shaped geometry to one Fe(1) and one P(5) atom. In the thirty-third O site, O(33) is bonded in a linear geometry to one Fe(4) and one P(3) atom. In the thirty-fourth O site, O(34) is bonded in a linear geometry to one Fe(3) and one P(4) atom. In the thirty-fifth O site, O(35) is bonded in a linear geometry to one Fe(2) and one P(1) atom. In the thirty-sixth O site, O(36) is bonded in an L-shaped geometry to one Fe(4) and one P(6) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Fe2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.431
_cell_length_b   7.822
_cell_length_c   14.107
_cell_angle_alpha   90.044
_cell_angle_beta   90.001
_cell_angle_gamma   89.973
_symmetry_Int_Tables_number   1
_cell_volume   709.647
_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
  Fe  Fe0  1  0.751  0.345  0.879  1.0
  Fe  Fe1  1  0.249  0.655  0.121  1.0
  Fe  Fe2  1  0.250  0.844  0.622  1.0
  Fe  Fe3  1  0.750  0.156  0.378  1.0
  Fe  Fe4  1  0.500  1.000  1.000  1.0
  Fe  Fe5  1  0.500  0.500  0.500  1.0
  Fe  Fe6  1  0.000  0.500  0.500  1.0
  Fe  Fe7  1  0.000  1.000  1.000  1.0
  P  P8  1  0.250  0.351  0.940  1.0
  P  P9  1  0.750  0.649  0.060  1.0
  P  P10  1  0.750  0.852  0.560  1.0
  P  P11  1  0.250  0.148  0.441  1.0
  P  P12  1  0.750  0.395  0.689  1.0
  P  P13  1  0.750  0.106  0.189  1.0
  P  P14  1  0.250  0.894  0.811  1.0
  P  P15  1  0.250  0.605  0.311  1.0
  O  O16  1  0.053  0.588  0.372  1.0
  O  O17  1  0.552  0.411  0.628  1.0
  O  O18  1  0.948  0.089  0.128  1.0
  O  O19  1  0.447  0.911  0.872  1.0
  O  O20  1  0.947  0.412  0.628  1.0
  O  O21  1  0.447  0.589  0.373  1.0
  O  O22  1  0.052  0.911  0.872  1.0
  O  O23  1  0.553  0.089  0.128  1.0
  O  O24  1  0.250  0.332  0.486  1.0
  O  O25  1  0.750  0.667  0.515  1.0
  O  O26  1  0.750  0.833  0.014  1.0
  O  O27  1  0.250  0.167  0.985  1.0
  O  O28  1  0.751  0.141  0.955  1.0
  O  O29  1  0.249  0.860  0.045  1.0
  O  O30  1  0.250  0.639  0.546  1.0
  O  O31  1  0.750  0.360  0.455  1.0
  O  O32  1  0.750  0.227  0.750  1.0
  O  O33  1  0.250  0.772  0.250  1.0
  O  O34  1  0.250  0.727  0.750  1.0
  O  O35  1  0.750  0.273  0.249  1.0
  O  O36  1  0.444  0.132  0.379  1.0
  O  O37  1  0.943  0.869  0.622  1.0
  O  O38  1  0.556  0.634  0.122  1.0
  O  O39  1  0.057  0.366  0.877  1.0
  O  O40  1  0.556  0.869  0.622  1.0
  O  O41  1  0.057  0.131  0.378  1.0
  O  O42  1  0.444  0.366  0.878  1.0
  O  O43  1  0.943  0.633  0.122  1.0
  O  O44  1  0.750  0.511  0.983  1.0
  O  O45  1  0.250  0.022  0.726  1.0
  O  O46  1  0.250  0.477  0.226  1.0
  O  O47  1  0.750  0.523  0.774  1.0
  O  O48  1  0.750  0.989  0.482  1.0
  O  O49  1  0.250  0.010  0.517  1.0
  O  O50  1  0.250  0.489  0.016  1.0
  O  O51  1  0.750  0.978  0.274  1.0
[/CIF]
.
The material structure described by Fe2O(PO4)2 crystallizes in the triclinic P1 space group. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(13), one O(17), one O(24), one O(27), one O(29), and one O(32) atom to form FeO6 octahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the second Fe site, Fe(2) is bonded to one O(14), one O(18), one O(23), one O(28), one O(31), and one O(35) atom to form FeO6 octahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(8)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the third Fe site, Fe(3) is bonded to one O(15), one O(19), one O(22), one O(25), one O(30), and one O(34) atom to form FeO6 octahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one P(7)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the fourth Fe site, Fe(4) is bonded to one O(16), one O(20), one O(21), one O(26), one O(33), and one O(36) atom to form FeO6 octahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the fifth Fe site, Fe(5) is bonded to one O(11), one O(12), one O(13), one O(14), one O(4), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and edges with two equivalent Fe(8)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(15), one O(16), one O(2), one O(6), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(8)O4 tetrahedra, and edges with two equivalent Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the seventh Fe site, Fe(7) is bonded to one O(1), one O(10), one O(15), one O(16), one O(5), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(8)O4 tetrahedra, and edges with two equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the eighth Fe site, Fe(8) is bonded to one O(11), one O(12), one O(13), one O(14), one O(3), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and edges with two equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are eight inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(24), one O(27), and one O(35) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and corners with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-52°. In the second P site, P(2) is bonded to one O(11), one O(23), one O(28), and one O(29) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-52°. In the third P site, P(3) is bonded to one O(10), one O(22), one O(25), and one O(33) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-52°. In the fourth P site, P(4) is bonded to one O(21), one O(26), one O(34), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and corners with two equivalent Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-52°. In the fifth P site, P(5) is bonded to one O(17), one O(2), one O(32), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the sixth P site, P(6) is bonded to one O(20), one O(3), one O(36), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the seventh P site, P(7) is bonded to one O(19), one O(30), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(5)O6 octahedra,  a cornercorner with one Fe(8)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the eighth P site, P(8) is bonded to one O(1), one O(18), one O(31), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(6)O6 octahedra,  a cornercorner with one Fe(7)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are thirty-six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Fe(7) and one P(8) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Fe(6) and one P(5) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Fe(8) and one P(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Fe(5) and one P(7) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Fe(7) and one P(5) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Fe(6) and one P(8) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Fe(8) and one P(7) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Fe(5) and one P(6) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(6), one Fe(7), and one P(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(6), one Fe(7), and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Fe(5), one Fe(8), and one P(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Fe(5), one Fe(8), and one P(1) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Fe(2), one Fe(5), and one Fe(8) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(7) atom. In the sixteenth O site, O(16) is bonded in a trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the seventeenth O site, O(17) is bonded in an L-shaped geometry to one Fe(1) and one P(5) atom. In the eighteenth O site, O(18) is bonded in an L-shaped geometry to one Fe(2) and one P(8) atom. In the nineteenth O site, O(19) is bonded in an L-shaped geometry to one Fe(3) and one P(7) atom. In the twentieth O site, O(20) is bonded in an L-shaped geometry to one Fe(4) and one P(6) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one Fe(4) and one P(4) atom. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(3) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the twenty-fourth O site, O(24) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(3) atom. In the twenty-sixth O site, O(26) is bonded in a bent 150 degrees geometry to one Fe(4) and one P(4) atom. In the twenty-seventh O site, O(27) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the twenty-eighth O site, O(28) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the twenty-ninth O site, O(29) is bonded in a linear geometry to one Fe(1) and one P(2) atom. In the thirtieth O site, O(30) is bonded in an L-shaped geometry to one Fe(3) and one P(7) atom. In the thirty-first O site, O(31) is bonded in an L-shaped geometry to one Fe(2) and one P(8) atom. In the thirty-second O site, O(32) is bonded in an L-shaped geometry to one Fe(1) and one P(5) atom. In the thirty-third O site, O(33) is bonded in a linear geometry to one Fe(4) and one P(3) atom. In the thirty-fourth O site, O(34) is bonded in a linear geometry to one Fe(3) and one P(4) atom. In the thirty-fifth O site, O(35) is bonded in a linear geometry to one Fe(2) and one P(1) atom. In the thirty-sixth O site, O(36) is bonded in an L-shaped geometry to one Fe(4) and one P(6) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Fe2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.431
_cell_length_b   7.822
_cell_length_c   14.107
_cell_angle_alpha   90.044
_cell_angle_beta   90.001
_cell_angle_gamma   89.973
_symmetry_Int_Tables_number   1
_cell_volume   709.647
_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
  Fe  Fe0  1  0.751  0.345  0.879  1.0
  Fe  Fe1  1  0.249  0.655  0.121  1.0
  Fe  Fe2  1  0.250  0.844  0.622  1.0
  Fe  Fe3  1  0.750  0.156  0.378  1.0
  Fe  Fe4  1  0.500  1.000  1.000  1.0
  Fe  Fe5  1  0.500  0.500  0.500  1.0
  Fe  Fe6  1  0.000  0.500  0.500  1.0
  Fe  Fe7  1  0.000  1.000  1.000  1.0
  P  P8  1  0.250  0.351  0.940  1.0
  P  P9  1  0.750  0.649  0.060  1.0
  P  P10  1  0.750  0.852  0.560  1.0
  P  P11  1  0.250  0.148  0.441  1.0
  P  P12  1  0.750  0.395  0.689  1.0
  P  P13  1  0.750  0.106  0.189  1.0
  P  P14  1  0.250  0.894  0.811  1.0
  P  P15  1  0.250  0.605  0.311  1.0
  O  O16  1  0.053  0.588  0.372  1.0
  O  O17  1  0.552  0.411  0.628  1.0
  O  O18  1  0.948  0.089  0.128  1.0
  O  O19  1  0.447  0.911  0.872  1.0
  O  O20  1  0.947  0.412  0.628  1.0
  O  O21  1  0.447  0.589  0.373  1.0
  O  O22  1  0.052  0.911  0.872  1.0
  O  O23  1  0.553  0.089  0.128  1.0
  O  O24  1  0.250  0.332  0.486  1.0
  O  O25  1  0.750  0.667  0.515  1.0
  O  O26  1  0.750  0.833  0.014  1.0
  O  O27  1  0.250  0.167  0.985  1.0
  O  O28  1  0.751  0.141  0.955  1.0
  O  O29  1  0.249  0.860  0.045  1.0
  O  O30  1  0.250  0.639  0.546  1.0
  O  O31  1  0.750  0.360  0.455  1.0
  O  O32  1  0.750  0.227  0.750  1.0
  O  O33  1  0.250  0.772  0.250  1.0
  O  O34  1  0.250  0.727  0.750  1.0
  O  O35  1  0.750  0.273  0.249  1.0
  O  O36  1  0.444  0.132  0.379  1.0
  O  O37  1  0.943  0.869  0.622  1.0
  O  O38  1  0.556  0.634  0.122  1.0
  O  O39  1  0.057  0.366  0.877  1.0
  O  O40  1  0.556  0.869  0.622  1.0
  O  O41  1  0.057  0.131  0.378  1.0
  O  O42  1  0.444  0.366  0.878  1.0
  O  O43  1  0.943  0.633  0.122  1.0
  O  O44  1  0.750  0.511  0.983  1.0
  O  O45  1  0.250  0.022  0.726  1.0
  O  O46  1  0.250  0.477  0.226  1.0
  O  O47  1  0.750  0.523  0.774  1.0
  O  O48  1  0.750  0.989  0.482  1.0
  O  O49  1  0.250  0.010  0.517  1.0
  O  O50  1  0.250  0.489  0.016  1.0
  O  O51  1  0.750  0.978  0.274  1.0
[/CIF]
.