The compound described by USe2O9 crystallizes in the monoclinic C2/c space group. U(1) is bonded to one O(2), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted UO7 pentagonal bipyramids that share corners with four equivalent Se(1)O4 tetrahedra. Se(1) is bonded to one O(3), one O(4), and two equivalent O(5) atoms to form SeO4 tetrahedra that share corners with two equivalent U(1)O7 pentagonal bipyramids and corners with two equivalent Se(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one U(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one U(1) atom. In the third O site, O(3) is bonded in a linear geometry to one U(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one U(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to two equivalent Se(1) atoms. is represented by the CIF card [CIF]
data_USe2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.715
_cell_length_b   8.715
_cell_length_c   5.740
_cell_angle_alpha   87.809
_cell_angle_beta   87.809
_cell_angle_gamma   99.305
_symmetry_Int_Tables_number   1
_cell_volume   429.485
_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  0.307  0.693  0.250  1.0
  U  U1  1  0.693  0.307  0.750  1.0
  Se  Se2  1  0.886  0.730  0.556  1.0
  Se  Se3  1  0.270  0.114  0.944  1.0
  Se  Se4  1  0.114  0.270  0.444  1.0
  Se  Se5  1  0.730  0.886  0.056  1.0
  O  O6  1  0.395  0.790  0.494  1.0
  O  O7  1  0.210  0.605  0.006  1.0
  O  O8  1  0.605  0.210  0.506  1.0
  O  O9  1  0.790  0.395  0.994  1.0
  O  O10  1  0.479  0.521  0.250  1.0
  O  O11  1  0.521  0.479  0.750  1.0
  O  O12  1  0.061  0.725  0.432  1.0
  O  O13  1  0.275  0.939  0.068  1.0
  O  O14  1  0.939  0.275  0.568  1.0
  O  O15  1  0.725  0.061  0.932  1.0
  O  O16  1  0.776  0.555  0.534  1.0
  O  O17  1  0.445  0.224  0.966  1.0
  O  O18  1  0.224  0.445  0.466  1.0
  O  O19  1  0.555  0.776  0.034  1.0
  O  O20  1  0.803  0.871  0.417  1.0
  O  O21  1  0.129  0.197  0.083  1.0
  O  O22  1  0.197  0.129  0.583  1.0
  O  O23  1  0.871  0.803  0.917  1.0
[/CIF]
.
The compound described by USe2O9 crystallizes in the monoclinic C2/c space group. U(1) is bonded to one O(2), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted UO7 pentagonal bipyramids that share corners with four equivalent Se(1)O4 tetrahedra. Se(1) is bonded to one O(3), one O(4), and two equivalent O(5) atoms to form SeO4 tetrahedra that share corners with two equivalent U(1)O7 pentagonal bipyramids and corners with two equivalent Se(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one U(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one U(1) atom. In the third O site, O(3) is bonded in a linear geometry to one U(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one U(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to two equivalent Se(1) atoms. is represented by the CIF card [CIF]
data_USe2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.715
_cell_length_b   8.715
_cell_length_c   5.740
_cell_angle_alpha   87.809
_cell_angle_beta   87.809
_cell_angle_gamma   99.305
_symmetry_Int_Tables_number   1
_cell_volume   429.485
_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  0.307  0.693  0.250  1.0
  U  U1  1  0.693  0.307  0.750  1.0
  Se  Se2  1  0.886  0.730  0.556  1.0
  Se  Se3  1  0.270  0.114  0.944  1.0
  Se  Se4  1  0.114  0.270  0.444  1.0
  Se  Se5  1  0.730  0.886  0.056  1.0
  O  O6  1  0.395  0.790  0.494  1.0
  O  O7  1  0.210  0.605  0.006  1.0
  O  O8  1  0.605  0.210  0.506  1.0
  O  O9  1  0.790  0.395  0.994  1.0
  O  O10  1  0.479  0.521  0.250  1.0
  O  O11  1  0.521  0.479  0.750  1.0
  O  O12  1  0.061  0.725  0.432  1.0
  O  O13  1  0.275  0.939  0.068  1.0
  O  O14  1  0.939  0.275  0.568  1.0
  O  O15  1  0.725  0.061  0.932  1.0
  O  O16  1  0.776  0.555  0.534  1.0
  O  O17  1  0.445  0.224  0.966  1.0
  O  O18  1  0.224  0.445  0.466  1.0
  O  O19  1  0.555  0.776  0.034  1.0
  O  O20  1  0.803  0.871  0.417  1.0
  O  O21  1  0.129  0.197  0.083  1.0
  O  O22  1  0.197  0.129  0.583  1.0
  O  O23  1  0.871  0.803  0.917  1.0
[/CIF]
.