The structure described by UYb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. U(1) is bonded to four equivalent Yb(2) and eight equivalent Yb(1) atoms to form UYb12 cuboctahedra that share corners with four equivalent U(1)Yb12 cuboctahedra, corners with eight equivalent Yb(2)Yb8U4 cuboctahedra, edges with eight equivalent U(1)Yb12 cuboctahedra, edges with sixteen equivalent Yb(1)Yb8U4 cuboctahedra, faces with four equivalent U(1)Yb12 cuboctahedra, faces with six equivalent Yb(2)Yb8U4 cuboctahedra, and faces with eight equivalent Yb(1)Yb8U4 cuboctahedra. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to four equivalent U(1), four equivalent Yb(1), and four equivalent Yb(2) atoms to form YbYb8U4 cuboctahedra that share corners with twelve equivalent Yb(1)Yb8U4 cuboctahedra, edges with eight equivalent U(1)Yb12 cuboctahedra, edges with eight equivalent Yb(1)Yb8U4 cuboctahedra, edges with eight equivalent Yb(2)Yb8U4 cuboctahedra, faces with four equivalent U(1)Yb12 cuboctahedra, faces with four equivalent Yb(2)Yb8U4 cuboctahedra, and faces with ten equivalent Yb(1)Yb8U4 cuboctahedra. In the second Yb site, Yb(2) is bonded to four equivalent U(1) and eight equivalent Yb(1) atoms to form distorted YbYb8U4 cuboctahedra that share corners with four equivalent Yb(2)Yb8U4 cuboctahedra, corners with eight equivalent U(1)Yb12 cuboctahedra, edges with eight equivalent Yb(2)Yb8U4 cuboctahedra, edges with sixteen equivalent Yb(1)Yb8U4 cuboctahedra, faces with four equivalent Yb(2)Yb8U4 cuboctahedra, faces with six equivalent U(1)Yb12 cuboctahedra, and faces with eight equivalent Yb(1)Yb8U4 cuboctahedra. is represented by the CIF file [CIF]
data_Yb3U
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.478
_cell_length_b   6.478
_cell_length_c   6.478
_cell_angle_alpha   133.096
_cell_angle_beta   133.096
_cell_angle_gamma   68.503
_symmetry_Int_Tables_number   1
_cell_volume   142.358
_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
  Yb  Yb0  1  0.750  0.250  0.500  1.0
  Yb  Yb1  1  0.250  0.750  0.500  1.0
  Yb  Yb2  1  0.500  0.500  0.000  1.0
  U  U3  1  0.000  0.000  0.000  1.0
[/CIF]
.
The structure described by UYb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. U(1) is bonded to four equivalent Yb(2) and eight equivalent Yb(1) atoms to form UYb12 cuboctahedra that share corners with four equivalent U(1)Yb12 cuboctahedra, corners with eight equivalent Yb(2)Yb8U4 cuboctahedra, edges with eight equivalent U(1)Yb12 cuboctahedra, edges with sixteen equivalent Yb(1)Yb8U4 cuboctahedra, faces with four equivalent U(1)Yb12 cuboctahedra, faces with six equivalent Yb(2)Yb8U4 cuboctahedra, and faces with eight equivalent Yb(1)Yb8U4 cuboctahedra. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to four equivalent U(1), four equivalent Yb(1), and four equivalent Yb(2) atoms to form YbYb8U4 cuboctahedra that share corners with twelve equivalent Yb(1)Yb8U4 cuboctahedra, edges with eight equivalent U(1)Yb12 cuboctahedra, edges with eight equivalent Yb(1)Yb8U4 cuboctahedra, edges with eight equivalent Yb(2)Yb8U4 cuboctahedra, faces with four equivalent U(1)Yb12 cuboctahedra, faces with four equivalent Yb(2)Yb8U4 cuboctahedra, and faces with ten equivalent Yb(1)Yb8U4 cuboctahedra. In the second Yb site, Yb(2) is bonded to four equivalent U(1) and eight equivalent Yb(1) atoms to form distorted YbYb8U4 cuboctahedra that share corners with four equivalent Yb(2)Yb8U4 cuboctahedra, corners with eight equivalent U(1)Yb12 cuboctahedra, edges with eight equivalent Yb(2)Yb8U4 cuboctahedra, edges with sixteen equivalent Yb(1)Yb8U4 cuboctahedra, faces with four equivalent Yb(2)Yb8U4 cuboctahedra, faces with six equivalent U(1)Yb12 cuboctahedra, and faces with eight equivalent Yb(1)Yb8U4 cuboctahedra. is represented by the CIF file [CIF]
data_Yb3U
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.478
_cell_length_b   6.478
_cell_length_c   6.478
_cell_angle_alpha   133.096
_cell_angle_beta   133.096
_cell_angle_gamma   68.503
_symmetry_Int_Tables_number   1
_cell_volume   142.358
_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
  Yb  Yb0  1  0.750  0.250  0.500  1.0
  Yb  Yb1  1  0.250  0.750  0.500  1.0
  Yb  Yb2  1  0.500  0.500  0.000  1.0
  U  U3  1  0.000  0.000  0.000  1.0
[/CIF]
.