The material described by Fe2P5O16 crystallizes in the monoclinic P2/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-43°. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-44°. In the third P site, P(3) is bonded to two equivalent O(4) and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Fe2P5O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.849
_cell_length_b   5.148
_cell_length_c   18.979
_cell_angle_alpha   89.591
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   669.242
_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
  Fe  Fe0  1  0.183  0.740  0.906  1.0
  Fe  Fe1  1  0.817  0.260  0.094  1.0
  Fe  Fe2  1  0.817  0.740  0.406  1.0
  Fe  Fe3  1  0.183  0.260  0.594  1.0
  P  P4  1  0.129  0.234  0.422  1.0
  P  P5  1  0.871  0.234  0.922  1.0
  P  P6  1  0.463  0.753  0.630  1.0
  P  P7  1  0.738  0.000  0.250  1.0
  P  P8  1  0.129  0.766  0.078  1.0
  P  P9  1  0.537  0.753  0.130  1.0
  P  P10  1  0.262  0.000  0.750  1.0
  P  P11  1  0.871  0.766  0.578  1.0
  P  P12  1  0.537  0.247  0.370  1.0
  P  P13  1  0.463  0.247  0.870  1.0
  O  O14  1  0.016  0.421  0.888  1.0
  O  O15  1  0.213  0.336  0.491  1.0
  O  O16  1  0.631  0.955  0.083  1.0
  O  O17  1  0.213  0.664  0.009  1.0
  O  O18  1  0.149  0.154  0.696  1.0
  O  O19  1  0.410  0.196  0.788  1.0
  O  O20  1  0.984  0.579  0.112  1.0
  O  O21  1  0.787  0.336  0.991  1.0
  O  O22  1  0.984  0.421  0.388  1.0
  O  O23  1  0.016  0.579  0.612  1.0
  O  O24  1  0.149  0.846  0.804  1.0
  O  O25  1  0.307  0.212  0.365  1.0
  O  O26  1  0.421  0.473  0.614  1.0
  O  O27  1  0.631  0.045  0.417  1.0
  O  O28  1  0.421  0.527  0.886  1.0
  O  O29  1  0.947  0.044  0.572  1.0
  O  O30  1  0.053  0.044  0.072  1.0
  O  O31  1  0.369  0.045  0.917  1.0
  O  O32  1  0.851  0.846  0.304  1.0
  O  O33  1  0.590  0.196  0.288  1.0
  O  O34  1  0.579  0.527  0.386  1.0
  O  O35  1  0.787  0.664  0.509  1.0
  O  O36  1  0.851  0.154  0.196  1.0
  O  O37  1  0.053  0.956  0.428  1.0
  O  O38  1  0.947  0.956  0.928  1.0
  O  O39  1  0.410  0.804  0.712  1.0
  O  O40  1  0.590  0.804  0.212  1.0
  O  O41  1  0.579  0.473  0.114  1.0
  O  O42  1  0.307  0.788  0.135  1.0
  O  O43  1  0.693  0.212  0.865  1.0
  O  O44  1  0.369  0.955  0.583  1.0
  O  O45  1  0.693  0.788  0.635  1.0
[/CIF]
.
The material described by Fe2P5O16 crystallizes in the monoclinic P2/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-43°. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-44°. In the third P site, P(3) is bonded to two equivalent O(4) and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Fe2P5O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.849
_cell_length_b   5.148
_cell_length_c   18.979
_cell_angle_alpha   89.591
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   669.242
_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
  Fe  Fe0  1  0.183  0.740  0.906  1.0
  Fe  Fe1  1  0.817  0.260  0.094  1.0
  Fe  Fe2  1  0.817  0.740  0.406  1.0
  Fe  Fe3  1  0.183  0.260  0.594  1.0
  P  P4  1  0.129  0.234  0.422  1.0
  P  P5  1  0.871  0.234  0.922  1.0
  P  P6  1  0.463  0.753  0.630  1.0
  P  P7  1  0.738  0.000  0.250  1.0
  P  P8  1  0.129  0.766  0.078  1.0
  P  P9  1  0.537  0.753  0.130  1.0
  P  P10  1  0.262  0.000  0.750  1.0
  P  P11  1  0.871  0.766  0.578  1.0
  P  P12  1  0.537  0.247  0.370  1.0
  P  P13  1  0.463  0.247  0.870  1.0
  O  O14  1  0.016  0.421  0.888  1.0
  O  O15  1  0.213  0.336  0.491  1.0
  O  O16  1  0.631  0.955  0.083  1.0
  O  O17  1  0.213  0.664  0.009  1.0
  O  O18  1  0.149  0.154  0.696  1.0
  O  O19  1  0.410  0.196  0.788  1.0
  O  O20  1  0.984  0.579  0.112  1.0
  O  O21  1  0.787  0.336  0.991  1.0
  O  O22  1  0.984  0.421  0.388  1.0
  O  O23  1  0.016  0.579  0.612  1.0
  O  O24  1  0.149  0.846  0.804  1.0
  O  O25  1  0.307  0.212  0.365  1.0
  O  O26  1  0.421  0.473  0.614  1.0
  O  O27  1  0.631  0.045  0.417  1.0
  O  O28  1  0.421  0.527  0.886  1.0
  O  O29  1  0.947  0.044  0.572  1.0
  O  O30  1  0.053  0.044  0.072  1.0
  O  O31  1  0.369  0.045  0.917  1.0
  O  O32  1  0.851  0.846  0.304  1.0
  O  O33  1  0.590  0.196  0.288  1.0
  O  O34  1  0.579  0.527  0.386  1.0
  O  O35  1  0.787  0.664  0.509  1.0
  O  O36  1  0.851  0.154  0.196  1.0
  O  O37  1  0.053  0.956  0.428  1.0
  O  O38  1  0.947  0.956  0.928  1.0
  O  O39  1  0.410  0.804  0.712  1.0
  O  O40  1  0.590  0.804  0.212  1.0
  O  O41  1  0.579  0.473  0.114  1.0
  O  O42  1  0.307  0.788  0.135  1.0
  O  O43  1  0.693  0.212  0.865  1.0
  O  O44  1  0.369  0.955  0.583  1.0
  O  O45  1  0.693  0.788  0.635  1.0
[/CIF]
.