The material described by Bi2P2O9 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form BiO6 octahedra that share corners with two equivalent Bi(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 51°. In the second Bi site, Bi(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form BiO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and edges with two equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. 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 Bi(2)O6 octahedra and corners with three equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-49°. 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 Bi(2)O6 octahedra and  an edgeedge with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a distorted L-shaped geometry to one Bi(1) and one P(2) atom. In the second O site, O(5) is bonded in a bent 150 degrees geometry to one Bi(1) and one P(1) atom. In the third O site, O(6) is bonded in a linear geometry to one Bi(1) and one P(1) atom. In the fourth O site, O(7) is bonded in a distorted L-shaped geometry to one Bi(1) and one P(2) atom. In the fifth O site, O(1) is bonded in a 2-coordinate geometry to one Bi(2) and one P(2) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Bi(2) and one P(1) atom. In the seventh O site, O(3) is bonded in a trigonal planar geometry to one Bi(1) and two equivalent Bi(2) atoms. is represented by the CIF file [CIF]
data_Bi2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.006
_cell_length_b   8.534
_cell_length_c   15.330
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   916.565
_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
  Bi  Bi0  1  0.250  0.865  0.375  1.0
  Bi  Bi1  1  0.750  0.135  0.625  1.0
  Bi  Bi2  1  0.750  0.365  0.125  1.0
  Bi  Bi3  1  0.250  0.635  0.875  1.0
  Bi  Bi4  1  0.000  0.500  0.500  1.0
  Bi  Bi5  1  0.000  0.000  0.000  1.0
  Bi  Bi6  1  0.500  0.000  0.000  1.0
  Bi  Bi7  1  0.500  0.500  0.500  1.0
  P  P8  1  0.750  0.855  0.435  1.0
  P  P9  1  0.250  0.145  0.565  1.0
  P  P10  1  0.250  0.355  0.065  1.0
  P  P11  1  0.750  0.645  0.935  1.0
  P  P12  1  0.250  0.890  0.189  1.0
  P  P13  1  0.250  0.610  0.689  1.0
  P  P14  1  0.750  0.390  0.311  1.0
  P  P15  1  0.750  0.110  0.811  1.0
  O  O16  1  0.567  0.099  0.868  1.0
  O  O17  1  0.067  0.901  0.132  1.0
  O  O18  1  0.433  0.599  0.632  1.0
  O  O19  1  0.933  0.401  0.368  1.0
  O  O20  1  0.433  0.901  0.132  1.0
  O  O21  1  0.933  0.099  0.868  1.0
  O  O22  1  0.567  0.401  0.368  1.0
  O  O23  1  0.067  0.599  0.632  1.0
  O  O24  1  0.750  0.816  0.980  1.0
  O  O25  1  0.250  0.184  0.020  1.0
  O  O26  1  0.250  0.316  0.520  1.0
  O  O27  1  0.750  0.684  0.480  1.0
  O  O28  1  0.250  0.637  0.448  1.0
  O  O29  1  0.750  0.363  0.552  1.0
  O  O30  1  0.750  0.137  0.052  1.0
  O  O31  1  0.250  0.863  0.948  1.0
  O  O32  1  0.250  0.737  0.243  1.0
  O  O33  1  0.750  0.263  0.757  1.0
  O  O34  1  0.750  0.237  0.257  1.0
  O  O35  1  0.250  0.763  0.743  1.0
  O  O36  1  0.927  0.638  0.875  1.0
  O  O37  1  0.427  0.362  0.125  1.0
  O  O38  1  0.073  0.138  0.625  1.0
  O  O39  1  0.573  0.862  0.375  1.0
  O  O40  1  0.073  0.362  0.125  1.0
  O  O41  1  0.573  0.638  0.875  1.0
  O  O42  1  0.927  0.862  0.375  1.0
  O  O43  1  0.427  0.138  0.625  1.0
  O  O44  1  0.250  0.019  0.495  1.0
  O  O45  1  0.750  0.525  0.239  1.0
  O  O46  1  0.750  0.975  0.739  1.0
  O  O47  1  0.250  0.025  0.261  1.0
  O  O48  1  0.250  0.481  0.995  1.0
  O  O49  1  0.750  0.519  0.005  1.0
  O  O50  1  0.750  0.981  0.505  1.0
  O  O51  1  0.250  0.475  0.761  1.0
[/CIF]
.
The material described by Bi2P2O9 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form BiO6 octahedra that share corners with two equivalent Bi(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 51°. In the second Bi site, Bi(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form BiO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and edges with two equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. 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 Bi(2)O6 octahedra and corners with three equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-49°. 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 Bi(2)O6 octahedra and  an edgeedge with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a distorted L-shaped geometry to one Bi(1) and one P(2) atom. In the second O site, O(5) is bonded in a bent 150 degrees geometry to one Bi(1) and one P(1) atom. In the third O site, O(6) is bonded in a linear geometry to one Bi(1) and one P(1) atom. In the fourth O site, O(7) is bonded in a distorted L-shaped geometry to one Bi(1) and one P(2) atom. In the fifth O site, O(1) is bonded in a 2-coordinate geometry to one Bi(2) and one P(2) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Bi(2) and one P(1) atom. In the seventh O site, O(3) is bonded in a trigonal planar geometry to one Bi(1) and two equivalent Bi(2) atoms. is represented by the CIF file [CIF]
data_Bi2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.006
_cell_length_b   8.534
_cell_length_c   15.330
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   916.565
_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
  Bi  Bi0  1  0.250  0.865  0.375  1.0
  Bi  Bi1  1  0.750  0.135  0.625  1.0
  Bi  Bi2  1  0.750  0.365  0.125  1.0
  Bi  Bi3  1  0.250  0.635  0.875  1.0
  Bi  Bi4  1  0.000  0.500  0.500  1.0
  Bi  Bi5  1  0.000  0.000  0.000  1.0
  Bi  Bi6  1  0.500  0.000  0.000  1.0
  Bi  Bi7  1  0.500  0.500  0.500  1.0
  P  P8  1  0.750  0.855  0.435  1.0
  P  P9  1  0.250  0.145  0.565  1.0
  P  P10  1  0.250  0.355  0.065  1.0
  P  P11  1  0.750  0.645  0.935  1.0
  P  P12  1  0.250  0.890  0.189  1.0
  P  P13  1  0.250  0.610  0.689  1.0
  P  P14  1  0.750  0.390  0.311  1.0
  P  P15  1  0.750  0.110  0.811  1.0
  O  O16  1  0.567  0.099  0.868  1.0
  O  O17  1  0.067  0.901  0.132  1.0
  O  O18  1  0.433  0.599  0.632  1.0
  O  O19  1  0.933  0.401  0.368  1.0
  O  O20  1  0.433  0.901  0.132  1.0
  O  O21  1  0.933  0.099  0.868  1.0
  O  O22  1  0.567  0.401  0.368  1.0
  O  O23  1  0.067  0.599  0.632  1.0
  O  O24  1  0.750  0.816  0.980  1.0
  O  O25  1  0.250  0.184  0.020  1.0
  O  O26  1  0.250  0.316  0.520  1.0
  O  O27  1  0.750  0.684  0.480  1.0
  O  O28  1  0.250  0.637  0.448  1.0
  O  O29  1  0.750  0.363  0.552  1.0
  O  O30  1  0.750  0.137  0.052  1.0
  O  O31  1  0.250  0.863  0.948  1.0
  O  O32  1  0.250  0.737  0.243  1.0
  O  O33  1  0.750  0.263  0.757  1.0
  O  O34  1  0.750  0.237  0.257  1.0
  O  O35  1  0.250  0.763  0.743  1.0
  O  O36  1  0.927  0.638  0.875  1.0
  O  O37  1  0.427  0.362  0.125  1.0
  O  O38  1  0.073  0.138  0.625  1.0
  O  O39  1  0.573  0.862  0.375  1.0
  O  O40  1  0.073  0.362  0.125  1.0
  O  O41  1  0.573  0.638  0.875  1.0
  O  O42  1  0.927  0.862  0.375  1.0
  O  O43  1  0.427  0.138  0.625  1.0
  O  O44  1  0.250  0.019  0.495  1.0
  O  O45  1  0.750  0.525  0.239  1.0
  O  O46  1  0.750  0.975  0.739  1.0
  O  O47  1  0.250  0.025  0.261  1.0
  O  O48  1  0.250  0.481  0.995  1.0
  O  O49  1  0.750  0.519  0.005  1.0
  O  O50  1  0.750  0.981  0.505  1.0
  O  O51  1  0.250  0.475  0.761  1.0
[/CIF]
.