The structure described by UNb2O7 crystallizes in the orthorhombic Cmcm space group. U(1) is bonded to one O(2), two equivalent O(5), and four equivalent O(1) atoms to form distorted edge-sharing UO7 hexagonal pyramids. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(3), and four equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent U(1) and one Nb(1) atom. In the second O site, O(2) is bonded in a linear geometry to one U(1) and one Nb(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and two equivalent Nb(2) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one U(1) and two equivalent Nb(2) atoms. is represented by the CIF file [CIF]
data_UNb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.818
_cell_length_b   10.818
_cell_length_c   6.543
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   159.674
_symmetry_Int_Tables_number   1
_cell_volume   265.989
_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
  U  U0  1  0.144  0.856  0.250  1.0
  U  U1  1  0.856  0.144  0.750  1.0
  Nb  Nb2  1  0.664  0.336  0.750  1.0
  Nb  Nb3  1  0.336  0.664  0.250  1.0
  Nb  Nb4  1  0.024  0.976  0.750  1.0
  Nb  Nb5  1  0.976  0.024  0.250  1.0
  O  O6  1  0.653  0.347  0.056  1.0
  O  O7  1  0.347  0.653  0.944  1.0
  O  O8  1  0.347  0.653  0.556  1.0
  O  O9  1  0.653  0.347  0.444  1.0
  O  O10  1  0.751  0.249  0.750  1.0
  O  O11  1  0.249  0.751  0.250  1.0
  O  O12  1  0.451  0.549  0.250  1.0
  O  O13  1  0.549  0.451  0.750  1.0
  O  O14  1  0.863  0.137  0.250  1.0
  O  O15  1  0.137  0.863  0.750  1.0
  O  O16  1  0.052  0.948  0.434  1.0
  O  O17  1  0.948  0.052  0.566  1.0
  O  O18  1  0.948  0.052  0.934  1.0
  O  O19  1  0.052  0.948  0.066  1.0
[/CIF]
.
The structure described by UNb2O7 crystallizes in the orthorhombic Cmcm space group. U(1) is bonded to one O(2), two equivalent O(5), and four equivalent O(1) atoms to form distorted edge-sharing UO7 hexagonal pyramids. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(3), and four equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent U(1) and one Nb(1) atom. In the second O site, O(2) is bonded in a linear geometry to one U(1) and one Nb(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and two equivalent Nb(2) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one U(1) and two equivalent Nb(2) atoms. is represented by the CIF file [CIF]
data_UNb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.818
_cell_length_b   10.818
_cell_length_c   6.543
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   159.674
_symmetry_Int_Tables_number   1
_cell_volume   265.989
_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
  U  U0  1  0.144  0.856  0.250  1.0
  U  U1  1  0.856  0.144  0.750  1.0
  Nb  Nb2  1  0.664  0.336  0.750  1.0
  Nb  Nb3  1  0.336  0.664  0.250  1.0
  Nb  Nb4  1  0.024  0.976  0.750  1.0
  Nb  Nb5  1  0.976  0.024  0.250  1.0
  O  O6  1  0.653  0.347  0.056  1.0
  O  O7  1  0.347  0.653  0.944  1.0
  O  O8  1  0.347  0.653  0.556  1.0
  O  O9  1  0.653  0.347  0.444  1.0
  O  O10  1  0.751  0.249  0.750  1.0
  O  O11  1  0.249  0.751  0.250  1.0
  O  O12  1  0.451  0.549  0.250  1.0
  O  O13  1  0.549  0.451  0.750  1.0
  O  O14  1  0.863  0.137  0.250  1.0
  O  O15  1  0.137  0.863  0.750  1.0
  O  O16  1  0.052  0.948  0.434  1.0
  O  O17  1  0.948  0.052  0.566  1.0
  O  O18  1  0.948  0.052  0.934  1.0
  O  O19  1  0.052  0.948  0.066  1.0
[/CIF]
.