The crystal structure described by Sb2P2O9 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and edges with two equivalent Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(6), and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent Sb(2)O6 octahedra and corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-48°. In the second P site, P(2) is bonded to one O(4), one O(7), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Sb(2)O6 octahedra and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are seven inequivalent O sites. In the first O site, O(4) is bonded in an L-shaped geometry to one Sb(1) and one P(2) atom. In the second O site, O(5) is bonded in a bent 150 degrees geometry to one Sb(1) and one P(1) atom. In the third O site, O(6) is bonded in a linear geometry to one Sb(1) and one P(1) atom. In the fourth O site, O(7) is bonded in an L-shaped geometry to one Sb(1) and one P(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Sb(2) and one P(2) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Sb(2) and one P(1) atom. In the seventh O site, O(3) is bonded in a 3-coordinate geometry to one Sb(1) and two equivalent Sb(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sb2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.637
_cell_length_b   8.416
_cell_length_c   14.672
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   819.580
_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
  Sb  Sb0  1  0.250  0.861  0.379  1.0
  Sb  Sb1  1  0.750  0.139  0.621  1.0
  Sb  Sb2  1  0.750  0.361  0.121  1.0
  Sb  Sb3  1  0.250  0.639  0.879  1.0
  Sb  Sb4  1  0.000  0.500  0.500  1.0
  Sb  Sb5  1  0.000  0.000  0.000  1.0
  Sb  Sb6  1  0.500  0.000  0.000  1.0
  Sb  Sb7  1  0.500  0.500  0.500  1.0
  P  P8  1  0.750  0.863  0.439  1.0
  P  P9  1  0.250  0.137  0.561  1.0
  P  P10  1  0.250  0.363  0.061  1.0
  P  P11  1  0.750  0.637  0.939  1.0
  P  P12  1  0.250  0.893  0.196  1.0
  P  P13  1  0.250  0.607  0.696  1.0
  P  P14  1  0.750  0.393  0.304  1.0
  P  P15  1  0.750  0.107  0.804  1.0
  O  O16  1  0.559  0.094  0.861  1.0
  O  O17  1  0.059  0.906  0.139  1.0
  O  O18  1  0.441  0.594  0.639  1.0
  O  O19  1  0.941  0.406  0.361  1.0
  O  O20  1  0.441  0.906  0.139  1.0
  O  O21  1  0.941  0.094  0.861  1.0
  O  O22  1  0.559  0.406  0.361  1.0
  O  O23  1  0.059  0.594  0.639  1.0
  O  O24  1  0.750  0.805  0.986  1.0
  O  O25  1  0.250  0.195  0.014  1.0
  O  O26  1  0.250  0.305  0.514  1.0
  O  O27  1  0.750  0.695  0.486  1.0
  O  O28  1  0.250  0.666  0.450  1.0
  O  O29  1  0.750  0.334  0.550  1.0
  O  O30  1  0.750  0.166  0.050  1.0
  O  O31  1  0.250  0.834  0.950  1.0
  O  O32  1  0.250  0.738  0.259  1.0
  O  O33  1  0.750  0.262  0.741  1.0
  O  O34  1  0.750  0.238  0.241  1.0
  O  O35  1  0.250  0.762  0.759  1.0
  O  O36  1  0.939  0.621  0.879  1.0
  O  O37  1  0.439  0.379  0.121  1.0
  O  O38  1  0.061  0.121  0.621  1.0
  O  O39  1  0.561  0.879  0.379  1.0
  O  O40  1  0.061  0.379  0.121  1.0
  O  O41  1  0.561  0.621  0.879  1.0
  O  O42  1  0.939  0.879  0.379  1.0
  O  O43  1  0.439  0.121  0.621  1.0
  O  O44  1  0.250  0.007  0.487  1.0
  O  O45  1  0.750  0.522  0.221  1.0
  O  O46  1  0.750  0.978  0.721  1.0
  O  O47  1  0.250  0.022  0.279  1.0
  O  O48  1  0.250  0.493  0.987  1.0
  O  O49  1  0.750  0.507  0.013  1.0
  O  O50  1  0.750  0.993  0.513  1.0
  O  O51  1  0.250  0.478  0.779  1.0
[/CIF]
.
The crystal structure described by Sb2P2O9 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and edges with two equivalent Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(6), and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent Sb(2)O6 octahedra and corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-48°. In the second P site, P(2) is bonded to one O(4), one O(7), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Sb(2)O6 octahedra and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are seven inequivalent O sites. In the first O site, O(4) is bonded in an L-shaped geometry to one Sb(1) and one P(2) atom. In the second O site, O(5) is bonded in a bent 150 degrees geometry to one Sb(1) and one P(1) atom. In the third O site, O(6) is bonded in a linear geometry to one Sb(1) and one P(1) atom. In the fourth O site, O(7) is bonded in an L-shaped geometry to one Sb(1) and one P(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Sb(2) and one P(2) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Sb(2) and one P(1) atom. In the seventh O site, O(3) is bonded in a 3-coordinate geometry to one Sb(1) and two equivalent Sb(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sb2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.637
_cell_length_b   8.416
_cell_length_c   14.672
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   819.580
_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
  Sb  Sb0  1  0.250  0.861  0.379  1.0
  Sb  Sb1  1  0.750  0.139  0.621  1.0
  Sb  Sb2  1  0.750  0.361  0.121  1.0
  Sb  Sb3  1  0.250  0.639  0.879  1.0
  Sb  Sb4  1  0.000  0.500  0.500  1.0
  Sb  Sb5  1  0.000  0.000  0.000  1.0
  Sb  Sb6  1  0.500  0.000  0.000  1.0
  Sb  Sb7  1  0.500  0.500  0.500  1.0
  P  P8  1  0.750  0.863  0.439  1.0
  P  P9  1  0.250  0.137  0.561  1.0
  P  P10  1  0.250  0.363  0.061  1.0
  P  P11  1  0.750  0.637  0.939  1.0
  P  P12  1  0.250  0.893  0.196  1.0
  P  P13  1  0.250  0.607  0.696  1.0
  P  P14  1  0.750  0.393  0.304  1.0
  P  P15  1  0.750  0.107  0.804  1.0
  O  O16  1  0.559  0.094  0.861  1.0
  O  O17  1  0.059  0.906  0.139  1.0
  O  O18  1  0.441  0.594  0.639  1.0
  O  O19  1  0.941  0.406  0.361  1.0
  O  O20  1  0.441  0.906  0.139  1.0
  O  O21  1  0.941  0.094  0.861  1.0
  O  O22  1  0.559  0.406  0.361  1.0
  O  O23  1  0.059  0.594  0.639  1.0
  O  O24  1  0.750  0.805  0.986  1.0
  O  O25  1  0.250  0.195  0.014  1.0
  O  O26  1  0.250  0.305  0.514  1.0
  O  O27  1  0.750  0.695  0.486  1.0
  O  O28  1  0.250  0.666  0.450  1.0
  O  O29  1  0.750  0.334  0.550  1.0
  O  O30  1  0.750  0.166  0.050  1.0
  O  O31  1  0.250  0.834  0.950  1.0
  O  O32  1  0.250  0.738  0.259  1.0
  O  O33  1  0.750  0.262  0.741  1.0
  O  O34  1  0.750  0.238  0.241  1.0
  O  O35  1  0.250  0.762  0.759  1.0
  O  O36  1  0.939  0.621  0.879  1.0
  O  O37  1  0.439  0.379  0.121  1.0
  O  O38  1  0.061  0.121  0.621  1.0
  O  O39  1  0.561  0.879  0.379  1.0
  O  O40  1  0.061  0.379  0.121  1.0
  O  O41  1  0.561  0.621  0.879  1.0
  O  O42  1  0.939  0.879  0.379  1.0
  O  O43  1  0.439  0.121  0.621  1.0
  O  O44  1  0.250  0.007  0.487  1.0
  O  O45  1  0.750  0.522  0.221  1.0
  O  O46  1  0.750  0.978  0.721  1.0
  O  O47  1  0.250  0.022  0.279  1.0
  O  O48  1  0.250  0.493  0.987  1.0
  O  O49  1  0.750  0.507  0.013  1.0
  O  O50  1  0.750  0.993  0.513  1.0
  O  O51  1  0.250  0.478  0.779  1.0
[/CIF]
.