The crystal structure described by U2Zn17 crystallizes in the trigonal R-3m space group. U(1) is bonded in a 19-coordinate geometry to one Zn(2), three equivalent Zn(3), six equivalent Zn(4), and nine equivalent Zn(1) atoms. There are four inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to three equivalent U(1), one Zn(2), two equivalent Zn(1), two equivalent Zn(3), and four equivalent Zn(4) atoms to form distorted ZnU3Zn9 cuboctahedra that share corners with five equivalent Zn(3)U2Zn10 cuboctahedra, corners with eight equivalent Zn(4)U2Zn10 cuboctahedra, corners with ten equivalent Zn(1)U3Zn9 cuboctahedra, edges with two equivalent Zn(4)U2Zn10 cuboctahedra, edges with three equivalent Zn(3)U2Zn10 cuboctahedra, edges with five equivalent Zn(1)U3Zn9 cuboctahedra, faces with three equivalent Zn(3)U2Zn10 cuboctahedra, faces with seven equivalent Zn(1)U3Zn9 cuboctahedra, and faces with ten equivalent Zn(4)U2Zn10 cuboctahedra. In the second Zn site, Zn(2) is bonded in a 14-coordinate geometry to one U(1), one Zn(2), three equivalent Zn(1), three equivalent Zn(3), and six equivalent Zn(4) atoms. In the third Zn site, Zn(3) is bonded to two equivalent U(1), two equivalent Zn(2), four equivalent Zn(1), and four equivalent Zn(4) atoms to form distorted ZnU2Zn10 cuboctahedra that share corners with four equivalent Zn(3)U2Zn10 cuboctahedra, corners with eight equivalent Zn(4)U2Zn10 cuboctahedra, corners with ten equivalent Zn(1)U3Zn9 cuboctahedra, edges with four equivalent Zn(4)U2Zn10 cuboctahedra, edges with six equivalent Zn(1)U3Zn9 cuboctahedra, faces with four equivalent Zn(3)U2Zn10 cuboctahedra, faces with six equivalent Zn(1)U3Zn9 cuboctahedra, and faces with eight equivalent Zn(4)U2Zn10 cuboctahedra. In the fourth Zn site, Zn(4) is bonded to two equivalent U(1), two equivalent Zn(2), two equivalent Zn(3), two equivalent Zn(4), and four equivalent Zn(1) atoms to form distorted ZnU2Zn10 cuboctahedra that share corners with four equivalent Zn(3)U2Zn10 cuboctahedra, corners with eight equivalent Zn(1)U3Zn9 cuboctahedra, corners with twelve equivalent Zn(4)U2Zn10 cuboctahedra,  an edgeedge with one Zn(4)U2Zn10 cuboctahedra, edges with two equivalent Zn(3)U2Zn10 cuboctahedra, edges with two equivalent Zn(1)U3Zn9 cuboctahedra, faces with four equivalent Zn(3)U2Zn10 cuboctahedra, faces with seven equivalent Zn(4)U2Zn10 cuboctahedra, and faces with ten equivalent Zn(1)U3Zn9 cuboctahedra. is represented by the CIF file [CIF]
data_U2Zn17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.716
_cell_length_b   6.717
_cell_length_c   6.716
_cell_angle_alpha   83.104
_cell_angle_beta   83.104
_cell_angle_gamma   83.104
_symmetry_Int_Tables_number   1
_cell_volume   296.900
_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  0.662  0.662  0.662  1.0
  U  U1  1  0.338  0.338  0.338  1.0
  Zn  Zn2  1  0.351  0.351  0.840  1.0
  Zn  Zn3  1  0.351  0.840  0.351  1.0
  Zn  Zn4  1  0.100  0.100  0.100  1.0
  Zn  Zn5  1  0.900  0.900  0.900  1.0
  Zn  Zn6  1  0.000  0.000  0.500  1.0
  Zn  Zn7  1  0.500  0.000  0.000  1.0
  Zn  Zn8  1  0.000  0.500  0.000  1.0
  Zn  Zn9  1  0.706  0.000  0.294  1.0
  Zn  Zn10  1  0.294  0.706  0.000  1.0
  Zn  Zn11  1  0.000  0.294  0.706  1.0
  Zn  Zn12  1  0.294  0.000  0.706  1.0
  Zn  Zn13  1  0.706  0.294  0.000  1.0
  Zn  Zn14  1  0.000  0.706  0.294  1.0
  Zn  Zn15  1  0.649  0.160  0.649  1.0
  Zn  Zn16  1  0.649  0.649  0.160  1.0
  Zn  Zn17  1  0.160  0.649  0.649  1.0
  Zn  Zn18  1  0.840  0.351  0.351  1.0
[/CIF]
.
The crystal structure described by U2Zn17 crystallizes in the trigonal R-3m space group. U(1) is bonded in a 19-coordinate geometry to one Zn(2), three equivalent Zn(3), six equivalent Zn(4), and nine equivalent Zn(1) atoms. There are four inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to three equivalent U(1), one Zn(2), two equivalent Zn(1), two equivalent Zn(3), and four equivalent Zn(4) atoms to form distorted ZnU3Zn9 cuboctahedra that share corners with five equivalent Zn(3)U2Zn10 cuboctahedra, corners with eight equivalent Zn(4)U2Zn10 cuboctahedra, corners with ten equivalent Zn(1)U3Zn9 cuboctahedra, edges with two equivalent Zn(4)U2Zn10 cuboctahedra, edges with three equivalent Zn(3)U2Zn10 cuboctahedra, edges with five equivalent Zn(1)U3Zn9 cuboctahedra, faces with three equivalent Zn(3)U2Zn10 cuboctahedra, faces with seven equivalent Zn(1)U3Zn9 cuboctahedra, and faces with ten equivalent Zn(4)U2Zn10 cuboctahedra. In the second Zn site, Zn(2) is bonded in a 14-coordinate geometry to one U(1), one Zn(2), three equivalent Zn(1), three equivalent Zn(3), and six equivalent Zn(4) atoms. In the third Zn site, Zn(3) is bonded to two equivalent U(1), two equivalent Zn(2), four equivalent Zn(1), and four equivalent Zn(4) atoms to form distorted ZnU2Zn10 cuboctahedra that share corners with four equivalent Zn(3)U2Zn10 cuboctahedra, corners with eight equivalent Zn(4)U2Zn10 cuboctahedra, corners with ten equivalent Zn(1)U3Zn9 cuboctahedra, edges with four equivalent Zn(4)U2Zn10 cuboctahedra, edges with six equivalent Zn(1)U3Zn9 cuboctahedra, faces with four equivalent Zn(3)U2Zn10 cuboctahedra, faces with six equivalent Zn(1)U3Zn9 cuboctahedra, and faces with eight equivalent Zn(4)U2Zn10 cuboctahedra. In the fourth Zn site, Zn(4) is bonded to two equivalent U(1), two equivalent Zn(2), two equivalent Zn(3), two equivalent Zn(4), and four equivalent Zn(1) atoms to form distorted ZnU2Zn10 cuboctahedra that share corners with four equivalent Zn(3)U2Zn10 cuboctahedra, corners with eight equivalent Zn(1)U3Zn9 cuboctahedra, corners with twelve equivalent Zn(4)U2Zn10 cuboctahedra,  an edgeedge with one Zn(4)U2Zn10 cuboctahedra, edges with two equivalent Zn(3)U2Zn10 cuboctahedra, edges with two equivalent Zn(1)U3Zn9 cuboctahedra, faces with four equivalent Zn(3)U2Zn10 cuboctahedra, faces with seven equivalent Zn(4)U2Zn10 cuboctahedra, and faces with ten equivalent Zn(1)U3Zn9 cuboctahedra. is represented by the CIF file [CIF]
data_U2Zn17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.716
_cell_length_b   6.717
_cell_length_c   6.716
_cell_angle_alpha   83.104
_cell_angle_beta   83.104
_cell_angle_gamma   83.104
_symmetry_Int_Tables_number   1
_cell_volume   296.900
_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  0.662  0.662  0.662  1.0
  U  U1  1  0.338  0.338  0.338  1.0
  Zn  Zn2  1  0.351  0.351  0.840  1.0
  Zn  Zn3  1  0.351  0.840  0.351  1.0
  Zn  Zn4  1  0.100  0.100  0.100  1.0
  Zn  Zn5  1  0.900  0.900  0.900  1.0
  Zn  Zn6  1  0.000  0.000  0.500  1.0
  Zn  Zn7  1  0.500  0.000  0.000  1.0
  Zn  Zn8  1  0.000  0.500  0.000  1.0
  Zn  Zn9  1  0.706  0.000  0.294  1.0
  Zn  Zn10  1  0.294  0.706  0.000  1.0
  Zn  Zn11  1  0.000  0.294  0.706  1.0
  Zn  Zn12  1  0.294  0.000  0.706  1.0
  Zn  Zn13  1  0.706  0.294  0.000  1.0
  Zn  Zn14  1  0.000  0.706  0.294  1.0
  Zn  Zn15  1  0.649  0.160  0.649  1.0
  Zn  Zn16  1  0.649  0.649  0.160  1.0
  Zn  Zn17  1  0.160  0.649  0.649  1.0
  Zn  Zn18  1  0.840  0.351  0.351  1.0
[/CIF]
.