The structure described by U2O5 crystallizes in the monoclinic C2/m space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(3), one O(7), three equivalent O(5), and three equivalent O(6) atoms. In the second U site, U(2) is bonded in a 11-coordinate geometry to one O(5), three equivalent O(1), three equivalent O(3), and four equivalent O(2) atoms. In the third U site, U(3) is bonded in a 11-coordinate geometry to one O(6), three equivalent O(7), three equivalent O(8), and four equivalent O(4) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent U(2) atoms. In the second O site, O(2) is bonded to four equivalent U(2) atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the third O site, O(3) is bonded in a single-bond geometry to one U(1) and three equivalent U(2) atoms. In the fourth O site, O(4) is bonded to four equivalent U(3) atoms to form OU4 trigonal pyramids that share corners with three equivalent O(8)U6 octahedra, corners with four equivalent O(6)U4 tetrahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(7)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and faces with three equivalent O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 40-41°. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one U(2) and three equivalent U(1) atoms. In the sixth O site, O(6) is bonded to one U(3) and three equivalent U(1) atoms to form OU4 tetrahedra that share corners with three equivalent O(8)U6 octahedra, corners with six equivalent O(6)U4 tetrahedra, corners with four equivalent O(4)U4 trigonal pyramids, and edges with three equivalent O(7)U4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the seventh O site, O(7) is bonded to one U(1) and three equivalent U(3) atoms to form distorted OU4 tetrahedra that share corners with six equivalent O(8)U6 octahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(6)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and  a faceface with one O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the eighth O site, O(8) is bonded to six equivalent U(3) atoms to form OU6 octahedra that share corners with six equivalent O(6)U4 tetrahedra, corners with twelve equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with six equivalent O(8)U6 octahedra, faces with two equivalent O(7)U4 tetrahedra, and faces with six equivalent O(4)U4 trigonal pyramids. is represented by the CIF card [CIF]
data_U2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.841
_cell_length_b   3.841
_cell_length_c   19.394
_cell_angle_alpha   84.868
_cell_angle_beta   84.868
_cell_angle_gamma   60.810
_symmetry_Int_Tables_number   1
_cell_volume   248.387
_cell_formula_units_Z   3
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  0.929  0.929  0.738  1.0
  U  U1  1  0.191  0.191  0.920  1.0
  U  U2  1  0.071  0.071  0.262  1.0
  U  U3  1  0.809  0.809  0.080  1.0
  U  U4  1  0.352  0.352  0.428  1.0
  U  U5  1  0.648  0.648  0.572  1.0
  O  O6  1  0.529  0.529  0.906  1.0
  O  O7  1  0.156  0.156  0.031  1.0
  O  O8  1  0.890  0.890  0.839  1.0
  O  O9  1  0.844  0.844  0.969  1.0
  O  O10  1  0.471  0.471  0.094  1.0
  O  O11  1  0.110  0.110  0.161  1.0
  O  O12  1  0.681  0.681  0.446  1.0
  O  O13  1  0.749  0.749  0.233  1.0
  O  O14  1  0.392  0.392  0.301  1.0
  O  O15  1  0.967  0.967  0.630  1.0
  O  O16  1  0.033  0.033  0.370  1.0
  O  O17  1  0.000  0.000  0.500  1.0
  O  O18  1  0.319  0.319  0.554  1.0
  O  O19  1  0.251  0.251  0.767  1.0
  O  O20  1  0.608  0.608  0.699  1.0
[/CIF]
.
The structure described by U2O5 crystallizes in the monoclinic C2/m space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to one O(3), one O(7), three equivalent O(5), and three equivalent O(6) atoms. In the second U site, U(2) is bonded in a 11-coordinate geometry to one O(5), three equivalent O(1), three equivalent O(3), and four equivalent O(2) atoms. In the third U site, U(3) is bonded in a 11-coordinate geometry to one O(6), three equivalent O(7), three equivalent O(8), and four equivalent O(4) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent U(2) atoms. In the second O site, O(2) is bonded to four equivalent U(2) atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the third O site, O(3) is bonded in a single-bond geometry to one U(1) and three equivalent U(2) atoms. In the fourth O site, O(4) is bonded to four equivalent U(3) atoms to form OU4 trigonal pyramids that share corners with three equivalent O(8)U6 octahedra, corners with four equivalent O(6)U4 tetrahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(7)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and faces with three equivalent O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 40-41°. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one U(2) and three equivalent U(1) atoms. In the sixth O site, O(6) is bonded to one U(3) and three equivalent U(1) atoms to form OU4 tetrahedra that share corners with three equivalent O(8)U6 octahedra, corners with six equivalent O(6)U4 tetrahedra, corners with four equivalent O(4)U4 trigonal pyramids, and edges with three equivalent O(7)U4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the seventh O site, O(7) is bonded to one U(1) and three equivalent U(3) atoms to form distorted OU4 tetrahedra that share corners with six equivalent O(8)U6 octahedra, corners with six equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with three equivalent O(6)U4 tetrahedra, edges with three equivalent O(4)U4 trigonal pyramids, and  a faceface with one O(8)U6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the eighth O site, O(8) is bonded to six equivalent U(3) atoms to form OU6 octahedra that share corners with six equivalent O(6)U4 tetrahedra, corners with twelve equivalent O(7)U4 tetrahedra, corners with six equivalent O(4)U4 trigonal pyramids, edges with six equivalent O(8)U6 octahedra, faces with two equivalent O(7)U4 tetrahedra, and faces with six equivalent O(4)U4 trigonal pyramids. is represented by the CIF card [CIF]
data_U2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.841
_cell_length_b   3.841
_cell_length_c   19.394
_cell_angle_alpha   84.868
_cell_angle_beta   84.868
_cell_angle_gamma   60.810
_symmetry_Int_Tables_number   1
_cell_volume   248.387
_cell_formula_units_Z   3
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  0.929  0.929  0.738  1.0
  U  U1  1  0.191  0.191  0.920  1.0
  U  U2  1  0.071  0.071  0.262  1.0
  U  U3  1  0.809  0.809  0.080  1.0
  U  U4  1  0.352  0.352  0.428  1.0
  U  U5  1  0.648  0.648  0.572  1.0
  O  O6  1  0.529  0.529  0.906  1.0
  O  O7  1  0.156  0.156  0.031  1.0
  O  O8  1  0.890  0.890  0.839  1.0
  O  O9  1  0.844  0.844  0.969  1.0
  O  O10  1  0.471  0.471  0.094  1.0
  O  O11  1  0.110  0.110  0.161  1.0
  O  O12  1  0.681  0.681  0.446  1.0
  O  O13  1  0.749  0.749  0.233  1.0
  O  O14  1  0.392  0.392  0.301  1.0
  O  O15  1  0.967  0.967  0.630  1.0
  O  O16  1  0.033  0.033  0.370  1.0
  O  O17  1  0.000  0.000  0.500  1.0
  O  O18  1  0.319  0.319  0.554  1.0
  O  O19  1  0.251  0.251  0.767  1.0
  O  O20  1  0.608  0.608  0.699  1.0
[/CIF]
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