The compound described by UCe2Se4 crystallizes in the tetragonal I-42d space group. U(1) is bonded to eight equivalent Se(1) atoms to form distorted USe8 hexagonal bipyramids that share corners with eight equivalent Ce(1)Se8 hexagonal bipyramids, edges with four equivalent U(1)Se8 hexagonal bipyramids, and faces with eight equivalent Ce(1)Se8 hexagonal bipyramids. Ce(1) is bonded to eight equivalent Se(1) atoms to form distorted CeSe8 hexagonal bipyramids that share corners with four equivalent U(1)Se8 hexagonal bipyramids, corners with four equivalent Ce(1)Se8 hexagonal bipyramids, edges with four equivalent Ce(1)Se8 hexagonal bipyramids, faces with four equivalent U(1)Se8 hexagonal bipyramids, and faces with four equivalent Ce(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent U(1) and four equivalent Ce(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeCe4U2 octahedra. The corner-sharing octahedral tilt angles range from 16-50°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ce2USe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.769
_cell_length_b   7.769
_cell_length_c   7.770
_cell_angle_alpha   109.344
_cell_angle_beta   109.344
_cell_angle_gamma   109.728
_symmetry_Int_Tables_number   1
_cell_volume   361.033
_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
  Ce  Ce0  1  0.625  0.001  0.876  1.0
  Ce  Ce1  1  0.999  0.875  0.624  1.0
  Ce  Ce2  1  0.125  0.749  0.124  1.0
  Ce  Ce3  1  0.251  0.375  0.376  1.0
  U  U4  1  0.500  0.500  1.000  1.0
  U  U5  1  0.750  0.250  0.500  1.0
  Se  Se6  1  0.528  0.778  0.399  1.0
  Se  Se7  1  0.871  0.972  0.250  1.0
  Se  Se8  1  0.722  0.622  0.750  1.0
  Se  Se9  1  0.028  0.278  0.899  1.0
  Se  Se10  1  0.872  0.473  0.251  1.0
  Se  Se11  1  0.378  0.129  0.101  1.0
  Se  Se12  1  0.222  0.621  0.749  1.0
  Se  Se13  1  0.379  0.128  0.601  1.0
[/CIF]
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The compound described by UCe2Se4 crystallizes in the tetragonal I-42d space group. U(1) is bonded to eight equivalent Se(1) atoms to form distorted USe8 hexagonal bipyramids that share corners with eight equivalent Ce(1)Se8 hexagonal bipyramids, edges with four equivalent U(1)Se8 hexagonal bipyramids, and faces with eight equivalent Ce(1)Se8 hexagonal bipyramids. Ce(1) is bonded to eight equivalent Se(1) atoms to form distorted CeSe8 hexagonal bipyramids that share corners with four equivalent U(1)Se8 hexagonal bipyramids, corners with four equivalent Ce(1)Se8 hexagonal bipyramids, edges with four equivalent Ce(1)Se8 hexagonal bipyramids, faces with four equivalent U(1)Se8 hexagonal bipyramids, and faces with four equivalent Ce(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent U(1) and four equivalent Ce(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeCe4U2 octahedra. The corner-sharing octahedral tilt angles range from 16-50°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ce2USe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.769
_cell_length_b   7.769
_cell_length_c   7.770
_cell_angle_alpha   109.344
_cell_angle_beta   109.344
_cell_angle_gamma   109.728
_symmetry_Int_Tables_number   1
_cell_volume   361.033
_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
  Ce  Ce0  1  0.625  0.001  0.876  1.0
  Ce  Ce1  1  0.999  0.875  0.624  1.0
  Ce  Ce2  1  0.125  0.749  0.124  1.0
  Ce  Ce3  1  0.251  0.375  0.376  1.0
  U  U4  1  0.500  0.500  1.000  1.0
  U  U5  1  0.750  0.250  0.500  1.0
  Se  Se6  1  0.528  0.778  0.399  1.0
  Se  Se7  1  0.871  0.972  0.250  1.0
  Se  Se8  1  0.722  0.622  0.750  1.0
  Se  Se9  1  0.028  0.278  0.899  1.0
  Se  Se10  1  0.872  0.473  0.251  1.0
  Se  Se11  1  0.378  0.129  0.101  1.0
  Se  Se12  1  0.222  0.621  0.749  1.0
  Se  Se13  1  0.379  0.128  0.601  1.0
[/CIF]
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