The material described by Nb2P4O15 crystallizes in the triclinic P-1 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(13), one O(2), one O(6), one O(7), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. In the second Nb site, Nb(2) is bonded to one O(1), one O(15), one O(3), one O(4), one O(5), and one O(8) atom to form distorted NbO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(14), one O(15), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 25-36°. In the second P site, P(2) is bonded to one O(1), one O(14), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-21°. In the third P site, P(3) is bonded to one O(10), one O(11), one O(6), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-26°. In the fourth P site, P(4) is bonded to one O(11), one O(13), one O(16), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-36°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Nb(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Nb(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Nb(2) and one P(4) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(3) atom. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one P(3) and one P(4) atom. In the twelfth O site, O(12) is bonded in a linear geometry to two equivalent P(1) atoms. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to two equivalent P(4) atoms. is represented by the CIF file [CIF]
data_Nb2P4O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.807
_cell_length_b   8.536
_cell_length_c   11.223
_cell_angle_alpha   74.297
_cell_angle_beta   89.701
_cell_angle_gamma   89.891
_symmetry_Int_Tables_number   1
_cell_volume   627.727
_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
  Nb  Nb0  1  0.738  0.704  0.855  1.0
  Nb  Nb1  1  0.262  0.296  0.145  1.0
  Nb  Nb2  1  0.234  0.294  0.648  1.0
  Nb  Nb3  1  0.766  0.706  0.352  1.0
  P  P4  1  0.113  0.913  0.623  1.0
  P  P5  1  0.439  0.683  0.602  1.0
  P  P6  1  0.062  0.685  0.099  1.0
  P  P7  1  0.561  0.317  0.398  1.0
  P  P8  1  0.614  0.085  0.876  1.0
  P  P9  1  0.887  0.087  0.377  1.0
  P  P10  1  0.938  0.315  0.901  1.0
  P  P11  1  0.386  0.915  0.124  1.0
  O  O12  1  0.322  0.526  0.642  1.0
  O  O13  1  0.557  0.662  0.968  1.0
  O  O14  1  0.035  0.335  0.549  1.0
  O  O15  1  0.443  0.338  0.032  1.0
  O  O16  1  0.509  0.795  0.213  1.0
  O  O17  1  0.446  0.300  0.517  1.0
  O  O18  1  0.033  0.301  0.026  1.0
  O  O19  1  0.565  0.710  0.707  1.0
  O  O20  1  0.917  0.715  0.194  1.0
  O  O21  1  0.678  0.474  0.358  1.0
  O  O22  1  0.988  0.791  0.709  1.0
  O  O23  1  0.491  0.205  0.787  1.0
  O  O24  1  0.967  0.699  0.974  1.0
  O  O25  1  0.177  0.528  0.146  1.0
  O  O26  1  0.823  0.472  0.854  1.0
  O  O27  1  0.789  0.165  0.932  1.0
  O  O28  1  0.211  0.835  0.068  1.0
  O  O29  1  0.000  0.000  0.500  1.0
  O  O30  1  0.012  0.209  0.291  1.0
  O  O31  1  0.965  0.665  0.451  1.0
  O  O32  1  0.708  0.952  0.826  1.0
  O  O33  1  0.289  0.834  0.565  1.0
  O  O34  1  0.554  0.700  0.483  1.0
  O  O35  1  0.435  0.290  0.293  1.0
  O  O36  1  0.083  0.285  0.806  1.0
  O  O37  1  0.292  0.048  0.174  1.0
  O  O38  1  0.205  0.044  0.674  1.0
  O  O39  1  0.795  0.956  0.326  1.0
  O  O40  1  0.711  0.166  0.435  1.0
  O  O41  1  0.500  0.000  0.000  1.0
[/CIF]
.
The material described by Nb2P4O15 crystallizes in the triclinic P-1 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(13), one O(2), one O(6), one O(7), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. In the second Nb site, Nb(2) is bonded to one O(1), one O(15), one O(3), one O(4), one O(5), and one O(8) atom to form distorted NbO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(14), one O(15), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 25-36°. In the second P site, P(2) is bonded to one O(1), one O(14), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-21°. In the third P site, P(3) is bonded to one O(10), one O(11), one O(6), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-26°. In the fourth P site, P(4) is bonded to one O(11), one O(13), one O(16), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-36°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Nb(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Nb(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Nb(2) and one P(4) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(3) atom. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one P(3) and one P(4) atom. In the twelfth O site, O(12) is bonded in a linear geometry to two equivalent P(1) atoms. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to two equivalent P(4) atoms. is represented by the CIF file [CIF]
data_Nb2P4O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.807
_cell_length_b   8.536
_cell_length_c   11.223
_cell_angle_alpha   74.297
_cell_angle_beta   89.701
_cell_angle_gamma   89.891
_symmetry_Int_Tables_number   1
_cell_volume   627.727
_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
  Nb  Nb0  1  0.738  0.704  0.855  1.0
  Nb  Nb1  1  0.262  0.296  0.145  1.0
  Nb  Nb2  1  0.234  0.294  0.648  1.0
  Nb  Nb3  1  0.766  0.706  0.352  1.0
  P  P4  1  0.113  0.913  0.623  1.0
  P  P5  1  0.439  0.683  0.602  1.0
  P  P6  1  0.062  0.685  0.099  1.0
  P  P7  1  0.561  0.317  0.398  1.0
  P  P8  1  0.614  0.085  0.876  1.0
  P  P9  1  0.887  0.087  0.377  1.0
  P  P10  1  0.938  0.315  0.901  1.0
  P  P11  1  0.386  0.915  0.124  1.0
  O  O12  1  0.322  0.526  0.642  1.0
  O  O13  1  0.557  0.662  0.968  1.0
  O  O14  1  0.035  0.335  0.549  1.0
  O  O15  1  0.443  0.338  0.032  1.0
  O  O16  1  0.509  0.795  0.213  1.0
  O  O17  1  0.446  0.300  0.517  1.0
  O  O18  1  0.033  0.301  0.026  1.0
  O  O19  1  0.565  0.710  0.707  1.0
  O  O20  1  0.917  0.715  0.194  1.0
  O  O21  1  0.678  0.474  0.358  1.0
  O  O22  1  0.988  0.791  0.709  1.0
  O  O23  1  0.491  0.205  0.787  1.0
  O  O24  1  0.967  0.699  0.974  1.0
  O  O25  1  0.177  0.528  0.146  1.0
  O  O26  1  0.823  0.472  0.854  1.0
  O  O27  1  0.789  0.165  0.932  1.0
  O  O28  1  0.211  0.835  0.068  1.0
  O  O29  1  0.000  0.000  0.500  1.0
  O  O30  1  0.012  0.209  0.291  1.0
  O  O31  1  0.965  0.665  0.451  1.0
  O  O32  1  0.708  0.952  0.826  1.0
  O  O33  1  0.289  0.834  0.565  1.0
  O  O34  1  0.554  0.700  0.483  1.0
  O  O35  1  0.435  0.290  0.293  1.0
  O  O36  1  0.083  0.285  0.806  1.0
  O  O37  1  0.292  0.048  0.174  1.0
  O  O38  1  0.205  0.044  0.674  1.0
  O  O39  1  0.795  0.956  0.326  1.0
  O  O40  1  0.711  0.166  0.435  1.0
  O  O41  1  0.500  0.000  0.000  1.0
[/CIF]
.