The compound described by U2AsSe is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent As(1) and four equivalent Se(1) atoms to form UAs2Se4 octahedra that share corners with six equivalent U(1)As2Se4 octahedra, edges with four equivalent U(1)As2Se4 octahedra, and edges with eight equivalent U(2)As4Se2 octahedra. The corner-sharing octahedra are not tilted. In the second U site, U(2) is bonded to four equivalent As(1) and two equivalent Se(1) atoms to form UAs4Se2 octahedra that share corners with six equivalent U(2)As4Se2 octahedra, edges with four equivalent U(2)As4Se2 octahedra, and edges with eight equivalent U(1)As2Se4 octahedra. The corner-sharing octahedra are not tilted. As(1) is bonded to two equivalent U(1) and four equivalent U(2) atoms to form AsU6 octahedra that share corners with six equivalent As(1)U6 octahedra, edges with four equivalent As(1)U6 octahedra, and edges with eight equivalent Se(1)U6 octahedra. The corner-sharing octahedra are not tilted. Se(1) is bonded to two equivalent U(2) and four equivalent U(1) atoms to form SeU6 octahedra that share corners with six equivalent Se(1)U6 octahedra, edges with four equivalent Se(1)U6 octahedra, and edges with eight equivalent As(1)U6 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_U2AsSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.186
_cell_length_b   4.186
_cell_length_c   5.923
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   103.775
_cell_formula_units_Z   1
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  0.500  1.0
  U  U1  1  0.500  0.500  0.000  1.0
  As  As2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.500  0.500  0.500  1.0
[/CIF]
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The compound described by U2AsSe is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent As(1) and four equivalent Se(1) atoms to form UAs2Se4 octahedra that share corners with six equivalent U(1)As2Se4 octahedra, edges with four equivalent U(1)As2Se4 octahedra, and edges with eight equivalent U(2)As4Se2 octahedra. The corner-sharing octahedra are not tilted. In the second U site, U(2) is bonded to four equivalent As(1) and two equivalent Se(1) atoms to form UAs4Se2 octahedra that share corners with six equivalent U(2)As4Se2 octahedra, edges with four equivalent U(2)As4Se2 octahedra, and edges with eight equivalent U(1)As2Se4 octahedra. The corner-sharing octahedra are not tilted. As(1) is bonded to two equivalent U(1) and four equivalent U(2) atoms to form AsU6 octahedra that share corners with six equivalent As(1)U6 octahedra, edges with four equivalent As(1)U6 octahedra, and edges with eight equivalent Se(1)U6 octahedra. The corner-sharing octahedra are not tilted. Se(1) is bonded to two equivalent U(2) and four equivalent U(1) atoms to form SeU6 octahedra that share corners with six equivalent Se(1)U6 octahedra, edges with four equivalent Se(1)U6 octahedra, and edges with eight equivalent As(1)U6 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_U2AsSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.186
_cell_length_b   4.186
_cell_length_c   5.923
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   103.775
_cell_formula_units_Z   1
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  0.500  1.0
  U  U1  1  0.500  0.500  0.000  1.0
  As  As2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.500  0.500  0.500  1.0
[/CIF]
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