The compound described by USe2 crystallizes in the hexagonal P-62m space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 9-coordinate geometry to three equivalent Se(1) and six equivalent Se(2) atoms. In the second U site, U(2) is bonded in a 9-coordinate geometry to three equivalent Se(2) and six equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one U(1) and four equivalent U(2) atoms to form distorted SeU5 trigonal bipyramids that share corners with six equivalent Se(2)U4 tetrahedra, corners with ten equivalent Se(1)U5 trigonal bipyramids, edges with six equivalent Se(2)U4 tetrahedra, and edges with six equivalent Se(1)U5 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent U(1) and two equivalent U(2) atoms to form SeU4 tetrahedra that share corners with ten equivalent Se(2)U4 tetrahedra, corners with six equivalent Se(1)U5 trigonal bipyramids, edges with two equivalent Se(2)U4 tetrahedra, and edges with six equivalent Se(1)U5 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_USe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.698
_cell_length_b   7.698
_cell_length_c   4.166
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   213.770
_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  0.000  0.000  0.000  1.0
  U  U1  1  0.667  0.333  0.500  1.0
  U  U2  1  0.333  0.667  0.500  1.0
  Se  Se3  1  0.000  0.597  0.000  1.0
  Se  Se4  1  0.403  0.403  0.000  1.0
  Se  Se5  1  0.597  0.000  0.000  1.0
  Se  Se6  1  0.259  0.000  0.500  1.0
  Se  Se7  1  0.741  0.741  0.500  1.0
  Se  Se8  1  0.000  0.259  0.500  1.0
[/CIF]
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The compound described by USe2 crystallizes in the hexagonal P-62m space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 9-coordinate geometry to three equivalent Se(1) and six equivalent Se(2) atoms. In the second U site, U(2) is bonded in a 9-coordinate geometry to three equivalent Se(2) and six equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one U(1) and four equivalent U(2) atoms to form distorted SeU5 trigonal bipyramids that share corners with six equivalent Se(2)U4 tetrahedra, corners with ten equivalent Se(1)U5 trigonal bipyramids, edges with six equivalent Se(2)U4 tetrahedra, and edges with six equivalent Se(1)U5 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent U(1) and two equivalent U(2) atoms to form SeU4 tetrahedra that share corners with ten equivalent Se(2)U4 tetrahedra, corners with six equivalent Se(1)U5 trigonal bipyramids, edges with two equivalent Se(2)U4 tetrahedra, and edges with six equivalent Se(1)U5 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_USe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.698
_cell_length_b   7.698
_cell_length_c   4.166
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   213.770
_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  0.000  0.000  0.000  1.0
  U  U1  1  0.667  0.333  0.500  1.0
  U  U2  1  0.333  0.667  0.500  1.0
  Se  Se3  1  0.000  0.597  0.000  1.0
  Se  Se4  1  0.403  0.403  0.000  1.0
  Se  Se5  1  0.597  0.000  0.000  1.0
  Se  Se6  1  0.259  0.000  0.500  1.0
  Se  Se7  1  0.741  0.741  0.500  1.0
  Se  Se8  1  0.000  0.259  0.500  1.0
[/CIF]
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