The structure described by U2Sm2Se3O4 crystallizes in the orthorhombic Pbam space group. U(1) is bonded in a 4-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent O(1), and two equivalent O(2) atoms. Sm(1) is bonded in a 8-coordinate geometry to one Se(2), four equivalent Se(1), one O(1), and two equivalent O(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to two equivalent U(1) and four equivalent Sm(1) atoms. In the second Se site, Se(2) is bonded to four equivalent U(1) and two equivalent Sm(1) atoms to form distorted SeSm2U4 octahedra that share corners with four equivalent O(2)Sm2U2 tetrahedra, edges with two equivalent Se(2)Sm2U4 octahedra, and edges with four equivalent O(2)Sm2U2 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent U(1) and one Sm(1) atom. In the second O site, O(2) is bonded to two equivalent U(1) and two equivalent Sm(1) atoms to form distorted OSm2U2 tetrahedra that share corners with two equivalent Se(2)Sm2U4 octahedra, corners with two equivalent O(2)Sm2U2 tetrahedra, edges with two equivalent Se(2)Sm2U4 octahedra, and  an edgeedge with one O(2)Sm2U2 tetrahedra. The corner-sharing octahedral tilt angles are 50°. is represented by the CIF file [CIF]
data_Sm2U2Se3O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.992
_cell_length_b   7.056
_cell_length_c   14.978
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   421.885
_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
  Sm  Sm0  1  0.000  0.710  0.152  1.0
  Sm  Sm1  1  0.000  0.290  0.848  1.0
  Sm  Sm2  1  0.000  0.210  0.348  1.0
  Sm  Sm3  1  0.000  0.790  0.652  1.0
  U  U4  1  0.500  0.796  0.423  1.0
  U  U5  1  0.500  0.204  0.577  1.0
  U  U6  1  0.500  0.296  0.077  1.0
  U  U7  1  0.500  0.704  0.923  1.0
  Se  Se8  1  0.500  0.502  0.277  1.0
  Se  Se9  1  0.500  0.498  0.723  1.0
  Se  Se10  1  0.500  0.002  0.223  1.0
  Se  Se11  1  0.500  0.998  0.777  1.0
  Se  Se12  1  0.000  0.500  0.500  1.0
  Se  Se13  1  0.000  0.000  0.000  1.0
  O  O14  1  0.000  0.889  0.390  1.0
  O  O15  1  0.000  0.111  0.610  1.0
  O  O16  1  0.000  0.389  0.110  1.0
  O  O17  1  0.000  0.611  0.890  1.0
  O  O18  1  0.500  0.639  0.067  1.0
  O  O19  1  0.500  0.361  0.933  1.0
  O  O20  1  0.500  0.139  0.433  1.0
  O  O21  1  0.500  0.861  0.567  1.0
[/CIF]
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The structure described by U2Sm2Se3O4 crystallizes in the orthorhombic Pbam space group. U(1) is bonded in a 4-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent O(1), and two equivalent O(2) atoms. Sm(1) is bonded in a 8-coordinate geometry to one Se(2), four equivalent Se(1), one O(1), and two equivalent O(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to two equivalent U(1) and four equivalent Sm(1) atoms. In the second Se site, Se(2) is bonded to four equivalent U(1) and two equivalent Sm(1) atoms to form distorted SeSm2U4 octahedra that share corners with four equivalent O(2)Sm2U2 tetrahedra, edges with two equivalent Se(2)Sm2U4 octahedra, and edges with four equivalent O(2)Sm2U2 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent U(1) and one Sm(1) atom. In the second O site, O(2) is bonded to two equivalent U(1) and two equivalent Sm(1) atoms to form distorted OSm2U2 tetrahedra that share corners with two equivalent Se(2)Sm2U4 octahedra, corners with two equivalent O(2)Sm2U2 tetrahedra, edges with two equivalent Se(2)Sm2U4 octahedra, and  an edgeedge with one O(2)Sm2U2 tetrahedra. The corner-sharing octahedral tilt angles are 50°. is represented by the CIF file [CIF]
data_Sm2U2Se3O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.992
_cell_length_b   7.056
_cell_length_c   14.978
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   421.885
_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
  Sm  Sm0  1  0.000  0.710  0.152  1.0
  Sm  Sm1  1  0.000  0.290  0.848  1.0
  Sm  Sm2  1  0.000  0.210  0.348  1.0
  Sm  Sm3  1  0.000  0.790  0.652  1.0
  U  U4  1  0.500  0.796  0.423  1.0
  U  U5  1  0.500  0.204  0.577  1.0
  U  U6  1  0.500  0.296  0.077  1.0
  U  U7  1  0.500  0.704  0.923  1.0
  Se  Se8  1  0.500  0.502  0.277  1.0
  Se  Se9  1  0.500  0.498  0.723  1.0
  Se  Se10  1  0.500  0.002  0.223  1.0
  Se  Se11  1  0.500  0.998  0.777  1.0
  Se  Se12  1  0.000  0.500  0.500  1.0
  Se  Se13  1  0.000  0.000  0.000  1.0
  O  O14  1  0.000  0.889  0.390  1.0
  O  O15  1  0.000  0.111  0.610  1.0
  O  O16  1  0.000  0.389  0.110  1.0
  O  O17  1  0.000  0.611  0.890  1.0
  O  O18  1  0.500  0.639  0.067  1.0
  O  O19  1  0.500  0.361  0.933  1.0
  O  O20  1  0.500  0.139  0.433  1.0
  O  O21  1  0.500  0.861  0.567  1.0
[/CIF]
.