The compound described by V2P5O16 crystallizes in the monoclinic P2/c space group. V(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form VO6 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(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-40°. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent V(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 40-41°. In the third P site, P(3) is bonded to two equivalent O(7) and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one V(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one V(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one V(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(1) 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 bent 150 degrees geometry to one V(1) and one P(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. is represented by the CIF file [CIF]
data_V2P5O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.818
_cell_length_b   5.135
_cell_length_c   19.072
_cell_angle_alpha   89.096
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   667.656
_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
  V  V0  1  0.819  0.749  0.907  1.0
  V  V1  1  0.819  0.251  0.593  1.0
  V  V2  1  0.181  0.749  0.407  1.0
  V  V3  1  0.181  0.251  0.093  1.0
  P  P4  1  0.125  0.245  0.924  1.0
  P  P5  1  0.536  0.253  0.869  1.0
  P  P6  1  0.726  0.000  0.750  1.0
  P  P7  1  0.536  0.747  0.631  1.0
  P  P8  1  0.125  0.755  0.576  1.0
  P  P9  1  0.875  0.245  0.424  1.0
  P  P10  1  0.464  0.253  0.369  1.0
  P  P11  1  0.274  0.000  0.250  1.0
  P  P12  1  0.464  0.747  0.131  1.0
  P  P13  1  0.875  0.755  0.076  1.0
  O  O14  1  0.213  0.321  0.994  1.0
  O  O15  1  0.039  0.973  0.924  1.0
  O  O16  1  0.632  0.048  0.915  1.0
  O  O17  1  0.586  0.533  0.884  1.0
  O  O18  1  0.990  0.453  0.893  1.0
  O  O19  1  0.305  0.226  0.869  1.0
  O  O20  1  0.841  0.849  0.804  1.0
  O  O21  1  0.577  0.198  0.787  1.0
  O  O22  1  0.577  0.802  0.713  1.0
  O  O23  1  0.841  0.151  0.696  1.0
  O  O24  1  0.305  0.774  0.631  1.0
  O  O25  1  0.990  0.547  0.607  1.0
  O  O26  1  0.586  0.467  0.616  1.0
  O  O27  1  0.632  0.952  0.585  1.0
  O  O28  1  0.039  0.027  0.576  1.0
  O  O29  1  0.213  0.679  0.506  1.0
  O  O30  1  0.787  0.321  0.494  1.0
  O  O31  1  0.961  0.973  0.424  1.0
  O  O32  1  0.368  0.048  0.415  1.0
  O  O33  1  0.414  0.533  0.384  1.0
  O  O34  1  0.010  0.453  0.393  1.0
  O  O35  1  0.695  0.226  0.369  1.0
  O  O36  1  0.159  0.849  0.304  1.0
  O  O37  1  0.423  0.198  0.287  1.0
  O  O38  1  0.423  0.802  0.213  1.0
  O  O39  1  0.159  0.151  0.196  1.0
  O  O40  1  0.695  0.774  0.131  1.0
  O  O41  1  0.010  0.547  0.107  1.0
  O  O42  1  0.414  0.467  0.116  1.0
  O  O43  1  0.368  0.952  0.085  1.0
  O  O44  1  0.961  0.027  0.076  1.0
  O  O45  1  0.787  0.679  0.006  1.0
[/CIF]
.
The compound described by V2P5O16 crystallizes in the monoclinic P2/c space group. V(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form VO6 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(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-40°. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent V(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 40-41°. In the third P site, P(3) is bonded to two equivalent O(7) and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one V(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one V(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one V(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(1) 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 bent 150 degrees geometry to one V(1) and one P(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. is represented by the CIF file [CIF]
data_V2P5O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.818
_cell_length_b   5.135
_cell_length_c   19.072
_cell_angle_alpha   89.096
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   667.656
_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
  V  V0  1  0.819  0.749  0.907  1.0
  V  V1  1  0.819  0.251  0.593  1.0
  V  V2  1  0.181  0.749  0.407  1.0
  V  V3  1  0.181  0.251  0.093  1.0
  P  P4  1  0.125  0.245  0.924  1.0
  P  P5  1  0.536  0.253  0.869  1.0
  P  P6  1  0.726  0.000  0.750  1.0
  P  P7  1  0.536  0.747  0.631  1.0
  P  P8  1  0.125  0.755  0.576  1.0
  P  P9  1  0.875  0.245  0.424  1.0
  P  P10  1  0.464  0.253  0.369  1.0
  P  P11  1  0.274  0.000  0.250  1.0
  P  P12  1  0.464  0.747  0.131  1.0
  P  P13  1  0.875  0.755  0.076  1.0
  O  O14  1  0.213  0.321  0.994  1.0
  O  O15  1  0.039  0.973  0.924  1.0
  O  O16  1  0.632  0.048  0.915  1.0
  O  O17  1  0.586  0.533  0.884  1.0
  O  O18  1  0.990  0.453  0.893  1.0
  O  O19  1  0.305  0.226  0.869  1.0
  O  O20  1  0.841  0.849  0.804  1.0
  O  O21  1  0.577  0.198  0.787  1.0
  O  O22  1  0.577  0.802  0.713  1.0
  O  O23  1  0.841  0.151  0.696  1.0
  O  O24  1  0.305  0.774  0.631  1.0
  O  O25  1  0.990  0.547  0.607  1.0
  O  O26  1  0.586  0.467  0.616  1.0
  O  O27  1  0.632  0.952  0.585  1.0
  O  O28  1  0.039  0.027  0.576  1.0
  O  O29  1  0.213  0.679  0.506  1.0
  O  O30  1  0.787  0.321  0.494  1.0
  O  O31  1  0.961  0.973  0.424  1.0
  O  O32  1  0.368  0.048  0.415  1.0
  O  O33  1  0.414  0.533  0.384  1.0
  O  O34  1  0.010  0.453  0.393  1.0
  O  O35  1  0.695  0.226  0.369  1.0
  O  O36  1  0.159  0.849  0.304  1.0
  O  O37  1  0.423  0.198  0.287  1.0
  O  O38  1  0.423  0.802  0.213  1.0
  O  O39  1  0.159  0.151  0.196  1.0
  O  O40  1  0.695  0.774  0.131  1.0
  O  O41  1  0.010  0.547  0.107  1.0
  O  O42  1  0.414  0.467  0.116  1.0
  O  O43  1  0.368  0.952  0.085  1.0
  O  O44  1  0.961  0.027  0.076  1.0
  O  O45  1  0.787  0.679  0.006  1.0
[/CIF]
.