The material described by UO3 crystallizes in the monoclinic P2_1 space group. There are five inequivalent U sites. In the first U site, U(1) is bonded to one O(1), one O(2), one O(5), one O(9), and two equivalent O(14) atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 30°. In the second U site, U(2) is bonded in a 2-coordinate geometry to one O(12), one O(15), one O(4), one O(7), one O(8), and one O(9) atom. In the third U site, U(3) is bonded in a 7-coordinate geometry to one O(10), one O(15), one O(8), two equivalent O(11), and two equivalent O(5) atoms. In the fourth U site, U(4) is bonded in a 7-coordinate geometry to one O(14), one O(3), one O(6), two equivalent O(1), and two equivalent O(13) atoms. In the fifth U site, U(5) is bonded in a 6-coordinate geometry to one O(11), one O(13), one O(2), one O(7), and two equivalent O(10) atoms. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one U(1) and two equivalent U(4) atoms. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one U(1) and one U(5) atom. In the third O site, O(3) is bonded in a single-bond geometry to one U(4) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one U(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one U(1) and two equivalent U(3) atoms. In the sixth O site, O(6) is bonded in a single-bond geometry to one U(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one U(2) and one U(5) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one U(2) and one U(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one U(1) and one U(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one U(3) and two equivalent U(5) atoms. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one U(5) and two equivalent U(3) atoms. In the twelfth O site, O(12) is bonded in a single-bond geometry to one U(2) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one U(5) and two equivalent U(4) atoms. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one U(4) and two equivalent U(1) atoms. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one U(2) and one U(3) atom. is represented by the CIF card [CIF]
data_UO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.510
_cell_length_b   4.075
_cell_length_c   10.486
_cell_angle_alpha   82.523
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   614.685
_cell_formula_units_Z   10
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  0.498  0.345  0.334  1.0
  U  U1  1  0.234  0.202  0.199  1.0
  U  U2  1  0.482  0.997  0.001  1.0
  U  U3  1  0.218  0.160  0.657  1.0
  U  U4  1  0.958  0.385  0.301  1.0
  U  U5  1  0.998  0.655  0.666  1.0
  U  U6  1  0.718  0.840  0.343  1.0
  U  U7  1  0.458  0.615  0.699  1.0
  U  U8  1  0.982  0.003  0.999  1.0
  U  U9  1  0.734  0.798  0.801  1.0
  O  O10  1  0.145  0.661  0.651  1.0
  O  O11  1  0.478  0.296  0.528  1.0
  O  O12  1  0.722  0.903  0.171  1.0
  O  O13  1  0.726  0.198  0.702  1.0
  O  O14  1  0.012  0.577  0.860  1.0
  O  O15  1  0.718  0.775  0.516  1.0
  O  O16  1  0.086  0.352  0.282  1.0
  O  O17  1  0.366  0.004  0.076  1.0
  O  O18  1  0.861  0.691  0.701  1.0
  O  O19  1  0.937  0.907  0.228  1.0
  O  O20  1  0.457  0.539  0.910  1.0
  O  O21  1  0.736  0.452  0.927  1.0
  O  O22  1  0.645  0.339  0.349  1.0
  O  O23  1  0.218  0.225  0.484  1.0
  O  O24  1  0.827  0.356  0.342  1.0
  O  O25  1  0.512  0.423  0.140  1.0
  O  O26  1  0.978  0.704  0.472  1.0
  O  O27  1  0.586  0.648  0.718  1.0
  O  O28  1  0.236  0.548  0.073  1.0
  O  O29  1  0.327  0.644  0.658  1.0
  O  O30  1  0.437  0.093  0.772  1.0
  O  O31  1  0.535  0.847  0.328  1.0
  O  O32  1  0.035  0.153  0.672  1.0
  O  O33  1  0.226  0.802  0.298  1.0
  O  O34  1  0.601  0.982  0.939  1.0
  O  O35  1  0.361  0.309  0.299  1.0
  O  O36  1  0.866  0.996  0.924  1.0
  O  O37  1  0.101  0.018  0.061  1.0
  O  O38  1  0.222  0.097  0.829  1.0
  O  O39  1  0.957  0.461  0.090  1.0
[/CIF]
.
The material described by UO3 crystallizes in the monoclinic P2_1 space group. There are five inequivalent U sites. In the first U site, U(1) is bonded to one O(1), one O(2), one O(5), one O(9), and two equivalent O(14) atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 30°. In the second U site, U(2) is bonded in a 2-coordinate geometry to one O(12), one O(15), one O(4), one O(7), one O(8), and one O(9) atom. In the third U site, U(3) is bonded in a 7-coordinate geometry to one O(10), one O(15), one O(8), two equivalent O(11), and two equivalent O(5) atoms. In the fourth U site, U(4) is bonded in a 7-coordinate geometry to one O(14), one O(3), one O(6), two equivalent O(1), and two equivalent O(13) atoms. In the fifth U site, U(5) is bonded in a 6-coordinate geometry to one O(11), one O(13), one O(2), one O(7), and two equivalent O(10) atoms. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one U(1) and two equivalent U(4) atoms. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one U(1) and one U(5) atom. In the third O site, O(3) is bonded in a single-bond geometry to one U(4) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one U(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one U(1) and two equivalent U(3) atoms. In the sixth O site, O(6) is bonded in a single-bond geometry to one U(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one U(2) and one U(5) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one U(2) and one U(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one U(1) and one U(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one U(3) and two equivalent U(5) atoms. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one U(5) and two equivalent U(3) atoms. In the twelfth O site, O(12) is bonded in a single-bond geometry to one U(2) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one U(5) and two equivalent U(4) atoms. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one U(4) and two equivalent U(1) atoms. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one U(2) and one U(3) atom. is represented by the CIF card [CIF]
data_UO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.510
_cell_length_b   4.075
_cell_length_c   10.486
_cell_angle_alpha   82.523
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   614.685
_cell_formula_units_Z   10
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  0.498  0.345  0.334  1.0
  U  U1  1  0.234  0.202  0.199  1.0
  U  U2  1  0.482  0.997  0.001  1.0
  U  U3  1  0.218  0.160  0.657  1.0
  U  U4  1  0.958  0.385  0.301  1.0
  U  U5  1  0.998  0.655  0.666  1.0
  U  U6  1  0.718  0.840  0.343  1.0
  U  U7  1  0.458  0.615  0.699  1.0
  U  U8  1  0.982  0.003  0.999  1.0
  U  U9  1  0.734  0.798  0.801  1.0
  O  O10  1  0.145  0.661  0.651  1.0
  O  O11  1  0.478  0.296  0.528  1.0
  O  O12  1  0.722  0.903  0.171  1.0
  O  O13  1  0.726  0.198  0.702  1.0
  O  O14  1  0.012  0.577  0.860  1.0
  O  O15  1  0.718  0.775  0.516  1.0
  O  O16  1  0.086  0.352  0.282  1.0
  O  O17  1  0.366  0.004  0.076  1.0
  O  O18  1  0.861  0.691  0.701  1.0
  O  O19  1  0.937  0.907  0.228  1.0
  O  O20  1  0.457  0.539  0.910  1.0
  O  O21  1  0.736  0.452  0.927  1.0
  O  O22  1  0.645  0.339  0.349  1.0
  O  O23  1  0.218  0.225  0.484  1.0
  O  O24  1  0.827  0.356  0.342  1.0
  O  O25  1  0.512  0.423  0.140  1.0
  O  O26  1  0.978  0.704  0.472  1.0
  O  O27  1  0.586  0.648  0.718  1.0
  O  O28  1  0.236  0.548  0.073  1.0
  O  O29  1  0.327  0.644  0.658  1.0
  O  O30  1  0.437  0.093  0.772  1.0
  O  O31  1  0.535  0.847  0.328  1.0
  O  O32  1  0.035  0.153  0.672  1.0
  O  O33  1  0.226  0.802  0.298  1.0
  O  O34  1  0.601  0.982  0.939  1.0
  O  O35  1  0.361  0.309  0.299  1.0
  O  O36  1  0.866  0.996  0.924  1.0
  O  O37  1  0.101  0.018  0.061  1.0
  O  O38  1  0.222  0.097  0.829  1.0
  O  O39  1  0.957  0.461  0.090  1.0
[/CIF]
.