The crystal structure described by Nb2P4H3O16 crystallizes in the triclinic P1 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(12), one O(14), one O(15), one O(2), one O(3), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)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(11), one O(16), one O(6), one O(8), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(16), one O(2), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-45°. In the second P site, P(2) is bonded to one O(11), one O(12), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(2)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-42°. In the third P site, P(3) is bonded to one O(10), one O(14), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(2)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-42°. In the fourth P site, P(4) is bonded to one O(1), one O(13), one O(15), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-44°. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(13) atom. In the third H site, H(3) is bonded in a linear geometry to one O(10) and one O(7) atom. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Nb(2) and one P(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one P(1) and one H(1) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(1) and one P(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(3) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one P(2) and one H(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Nb(2) and one P(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one P(3) and one H(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a linear geometry to one Nb(1) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a water-like geometry to one P(4) and one H(2) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(3) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to one Nb(2) and one P(1) atom. is represented by the CIF file [CIF]
data_Nb2P4H3O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.122
_cell_length_b   7.539
_cell_length_c   8.224
_cell_angle_alpha   90.961
_cell_angle_beta   91.835
_cell_angle_gamma   103.528
_symmetry_Int_Tables_number   1
_cell_volume   308.475
_cell_formula_units_Z   1
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  0.998  0.497  0.003  1.0
  Nb  Nb1  1  0.500  0.002  0.499  1.0
  P  P2  1  0.108  0.257  0.663  1.0
  P  P3  1  0.383  0.229  0.145  1.0
  P  P4  1  0.611  0.763  0.851  1.0
  P  P5  1  0.891  0.744  0.337  1.0
  H  H6  1  0.397  0.447  0.552  1.0
  H  H7  1  0.601  0.550  0.444  1.0
  H  H8  1  0.947  0.979  0.987  1.0
  O  O9  1  0.138  0.851  0.437  1.0
  O  O10  1  0.020  0.309  0.829  1.0
  O  O11  1  0.203  0.374  0.155  1.0
  O  O12  1  0.212  0.445  0.574  1.0
  O  O13  1  0.351  0.659  0.933  1.0
  O  O14  1  0.541  0.811  0.676  1.0
  O  O15  1  0.242  0.064  0.048  1.0
  O  O16  1  0.333  0.155  0.669  1.0
  O  O17  1  0.667  0.846  0.330  1.0
  O  O18  1  0.746  0.937  0.951  1.0
  O  O19  1  0.458  0.191  0.325  1.0
  O  O20  1  0.651  0.342  0.069  1.0
  O  O21  1  0.788  0.557  0.428  1.0
  O  O22  1  0.804  0.631  0.844  1.0
  O  O23  1  0.978  0.692  0.170  1.0
  O  O24  1  0.862  0.149  0.563  1.0
[/CIF]
.
The crystal structure described by Nb2P4H3O16 crystallizes in the triclinic P1 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(12), one O(14), one O(15), one O(2), one O(3), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)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(11), one O(16), one O(6), one O(8), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(16), one O(2), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-45°. In the second P site, P(2) is bonded to one O(11), one O(12), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(2)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-42°. In the third P site, P(3) is bonded to one O(10), one O(14), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(2)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-42°. In the fourth P site, P(4) is bonded to one O(1), one O(13), one O(15), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-44°. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(13) atom. In the third H site, H(3) is bonded in a linear geometry to one O(10) and one O(7) atom. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Nb(2) and one P(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one P(1) and one H(1) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(1) and one P(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(3) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one P(2) and one H(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Nb(2) and one P(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one P(3) and one H(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a linear geometry to one Nb(1) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a water-like geometry to one P(4) and one H(2) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(3) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to one Nb(2) and one P(1) atom. is represented by the CIF file [CIF]
data_Nb2P4H3O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.122
_cell_length_b   7.539
_cell_length_c   8.224
_cell_angle_alpha   90.961
_cell_angle_beta   91.835
_cell_angle_gamma   103.528
_symmetry_Int_Tables_number   1
_cell_volume   308.475
_cell_formula_units_Z   1
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  0.998  0.497  0.003  1.0
  Nb  Nb1  1  0.500  0.002  0.499  1.0
  P  P2  1  0.108  0.257  0.663  1.0
  P  P3  1  0.383  0.229  0.145  1.0
  P  P4  1  0.611  0.763  0.851  1.0
  P  P5  1  0.891  0.744  0.337  1.0
  H  H6  1  0.397  0.447  0.552  1.0
  H  H7  1  0.601  0.550  0.444  1.0
  H  H8  1  0.947  0.979  0.987  1.0
  O  O9  1  0.138  0.851  0.437  1.0
  O  O10  1  0.020  0.309  0.829  1.0
  O  O11  1  0.203  0.374  0.155  1.0
  O  O12  1  0.212  0.445  0.574  1.0
  O  O13  1  0.351  0.659  0.933  1.0
  O  O14  1  0.541  0.811  0.676  1.0
  O  O15  1  0.242  0.064  0.048  1.0
  O  O16  1  0.333  0.155  0.669  1.0
  O  O17  1  0.667  0.846  0.330  1.0
  O  O18  1  0.746  0.937  0.951  1.0
  O  O19  1  0.458  0.191  0.325  1.0
  O  O20  1  0.651  0.342  0.069  1.0
  O  O21  1  0.788  0.557  0.428  1.0
  O  O22  1  0.804  0.631  0.844  1.0
  O  O23  1  0.978  0.692  0.170  1.0
  O  O24  1  0.862  0.149  0.563  1.0
[/CIF]
.