The crystal structure described by Fe3(P2O7)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), one O(7), and two equivalent O(3) atoms to form FeO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 63°. In the second Fe site, Fe(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 41°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 38-56°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Fe3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.613
_cell_length_b   6.890
_cell_length_c   7.466
_cell_angle_alpha   76.951
_cell_angle_beta   77.821
_cell_angle_gamma   70.381
_symmetry_Int_Tables_number   1
_cell_volume   262.046
_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
  Fe  Fe0  1  0.770  0.510  0.669  1.0
  Fe  Fe1  1  0.230  0.490  0.331  1.0
  Fe  Fe2  1  0.000  0.000  0.000  1.0
  P  P3  1  0.207  0.712  0.666  1.0
  P  P4  1  0.381  0.297  0.939  1.0
  P  P5  1  0.619  0.703  0.061  1.0
  P  P6  1  0.792  0.288  0.334  1.0
  O  O7  1  0.469  0.698  0.552  1.0
  O  O8  1  0.747  0.845  0.109  1.0
  O  O9  1  0.952  0.345  0.453  1.0
  O  O10  1  0.253  0.155  0.891  1.0
  O  O11  1  0.048  0.655  0.547  1.0
  O  O12  1  0.333  0.306  0.144  1.0
  O  O13  1  0.070  0.907  0.752  1.0
  O  O14  1  0.235  0.528  0.845  1.0
  O  O15  1  0.930  0.093  0.248  1.0
  O  O16  1  0.531  0.302  0.448  1.0
  O  O17  1  0.667  0.694  0.856  1.0
  O  O18  1  0.671  0.257  0.859  1.0
  O  O19  1  0.765  0.472  0.155  1.0
  O  O20  1  0.329  0.743  0.141  1.0
[/CIF]
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The crystal structure described by Fe3(P2O7)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), one O(7), and two equivalent O(3) atoms to form FeO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 63°. In the second Fe site, Fe(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 41°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 38-56°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Fe3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.613
_cell_length_b   6.890
_cell_length_c   7.466
_cell_angle_alpha   76.951
_cell_angle_beta   77.821
_cell_angle_gamma   70.381
_symmetry_Int_Tables_number   1
_cell_volume   262.046
_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
  Fe  Fe0  1  0.770  0.510  0.669  1.0
  Fe  Fe1  1  0.230  0.490  0.331  1.0
  Fe  Fe2  1  0.000  0.000  0.000  1.0
  P  P3  1  0.207  0.712  0.666  1.0
  P  P4  1  0.381  0.297  0.939  1.0
  P  P5  1  0.619  0.703  0.061  1.0
  P  P6  1  0.792  0.288  0.334  1.0
  O  O7  1  0.469  0.698  0.552  1.0
  O  O8  1  0.747  0.845  0.109  1.0
  O  O9  1  0.952  0.345  0.453  1.0
  O  O10  1  0.253  0.155  0.891  1.0
  O  O11  1  0.048  0.655  0.547  1.0
  O  O12  1  0.333  0.306  0.144  1.0
  O  O13  1  0.070  0.907  0.752  1.0
  O  O14  1  0.235  0.528  0.845  1.0
  O  O15  1  0.930  0.093  0.248  1.0
  O  O16  1  0.531  0.302  0.448  1.0
  O  O17  1  0.667  0.694  0.856  1.0
  O  O18  1  0.671  0.257  0.859  1.0
  O  O19  1  0.765  0.472  0.155  1.0
  O  O20  1  0.329  0.743  0.141  1.0
[/CIF]
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