The material described by UNb6O16 crystallizes in the monoclinic C2 space group. U(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form distorted UO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 pentagonal pyramids, and edges with two equivalent U(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-64°. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form distorted NbO6 octahedra that share corners with two equivalent U(1)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 pentagonal pyramid,  an edgeedge with one Nb(1)O6 octahedra, and edges with two equivalent Nb(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 36-64°. In the second Nb site, Nb(2) is bonded to one O(2), one O(3), one O(6), one O(7), and two equivalent O(4) atoms to form distorted NbO6 pentagonal pyramids that share corners with two equivalent U(1)O6 octahedra, corners with two equivalent Nb(2)O6 pentagonal pyramids, corners with two equivalent Nb(3)O6 pentagonal pyramids, and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-67°. In the third Nb site, Nb(3) is bonded to one O(5), one O(6), one O(7), and three equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing NbO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 9°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one U(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Nb(2) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent U(1) and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Nb(2) atoms. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(1) and one Nb(3) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to three equivalent Nb(3) atoms. is represented by the CIF card [CIF]
data_UNb6O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.537
_cell_length_b   11.537
_cell_length_c   7.438
_cell_angle_alpha   83.859
_cell_angle_beta   83.859
_cell_angle_gamma   19.095
_symmetry_Int_Tables_number   1
_cell_volume   321.938
_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
  U  U0  1  0.993  0.007  0.000  1.0
  Nb  Nb1  1  0.903  0.952  0.531  1.0
  Nb  Nb2  1  0.322  0.413  0.891  1.0
  Nb  Nb3  1  0.875  0.682  0.324  1.0
  Nb  Nb4  1  0.318  0.125  0.676  1.0
  Nb  Nb5  1  0.587  0.678  0.109  1.0
  Nb  Nb6  1  0.048  0.097  0.469  1.0
  O  O7  1  0.971  0.002  0.325  1.0
  O  O8  1  0.397  0.446  0.614  1.0
  O  O9  1  0.442  0.446  0.020  1.0
  O  O10  1  0.863  0.923  0.827  1.0
  O  O11  1  0.863  0.856  0.420  1.0
  O  O12  1  0.333  0.257  0.786  1.0
  O  O13  1  0.109  0.539  0.108  1.0
  O  O14  1  0.349  0.183  0.405  1.0
  O  O15  1  0.817  0.651  0.595  1.0
  O  O16  1  0.461  0.891  0.892  1.0
  O  O17  1  0.743  0.667  0.214  1.0
  O  O18  1  0.144  0.137  0.580  1.0
  O  O19  1  0.077  0.137  0.173  1.0
  O  O20  1  0.554  0.558  0.980  1.0
  O  O21  1  0.554  0.603  0.386  1.0
  O  O22  1  0.998  0.029  0.675  1.0
[/CIF]
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The material described by UNb6O16 crystallizes in the monoclinic C2 space group. U(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form distorted UO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 pentagonal pyramids, and edges with two equivalent U(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-64°. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form distorted NbO6 octahedra that share corners with two equivalent U(1)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 pentagonal pyramid,  an edgeedge with one Nb(1)O6 octahedra, and edges with two equivalent Nb(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 36-64°. In the second Nb site, Nb(2) is bonded to one O(2), one O(3), one O(6), one O(7), and two equivalent O(4) atoms to form distorted NbO6 pentagonal pyramids that share corners with two equivalent U(1)O6 octahedra, corners with two equivalent Nb(2)O6 pentagonal pyramids, corners with two equivalent Nb(3)O6 pentagonal pyramids, and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-67°. In the third Nb site, Nb(3) is bonded to one O(5), one O(6), one O(7), and three equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing NbO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 9°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one U(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Nb(2) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent U(1) and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Nb(2) atoms. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(1) and one Nb(3) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to three equivalent Nb(3) atoms. is represented by the CIF card [CIF]
data_UNb6O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.537
_cell_length_b   11.537
_cell_length_c   7.438
_cell_angle_alpha   83.859
_cell_angle_beta   83.859
_cell_angle_gamma   19.095
_symmetry_Int_Tables_number   1
_cell_volume   321.938
_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
  U  U0  1  0.993  0.007  0.000  1.0
  Nb  Nb1  1  0.903  0.952  0.531  1.0
  Nb  Nb2  1  0.322  0.413  0.891  1.0
  Nb  Nb3  1  0.875  0.682  0.324  1.0
  Nb  Nb4  1  0.318  0.125  0.676  1.0
  Nb  Nb5  1  0.587  0.678  0.109  1.0
  Nb  Nb6  1  0.048  0.097  0.469  1.0
  O  O7  1  0.971  0.002  0.325  1.0
  O  O8  1  0.397  0.446  0.614  1.0
  O  O9  1  0.442  0.446  0.020  1.0
  O  O10  1  0.863  0.923  0.827  1.0
  O  O11  1  0.863  0.856  0.420  1.0
  O  O12  1  0.333  0.257  0.786  1.0
  O  O13  1  0.109  0.539  0.108  1.0
  O  O14  1  0.349  0.183  0.405  1.0
  O  O15  1  0.817  0.651  0.595  1.0
  O  O16  1  0.461  0.891  0.892  1.0
  O  O17  1  0.743  0.667  0.214  1.0
  O  O18  1  0.144  0.137  0.580  1.0
  O  O19  1  0.077  0.137  0.173  1.0
  O  O20  1  0.554  0.558  0.980  1.0
  O  O21  1  0.554  0.603  0.386  1.0
  O  O22  1  0.998  0.029  0.675  1.0
[/CIF]
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