The crystal structure described by UHf(TaC2)2 is alpha Po-derived structured and crystallizes in the trigonal R3m space group. U(1) is bonded to three equivalent C(3) and three equivalent C(4) atoms to form UC6 octahedra that share corners with three equivalent Hf(1)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Hf(1)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent U(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. Hf(1) is bonded to three equivalent C(2) and three equivalent C(3) atoms to form HfC6 octahedra that share corners with three equivalent U(1)C6 octahedra, corners with three equivalent Ta(2)C6 octahedra, edges with three equivalent U(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, and edges with six equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent C(1) and three equivalent C(4) atoms to form TaC6 octahedra that share corners with three equivalent U(1)C6 octahedra, corners with three equivalent Ta(2)C6 octahedra, edges with three equivalent U(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, and edges with six equivalent Ta(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the second Ta site, Ta(2) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form TaC6 octahedra that share corners with three equivalent Hf(1)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Hf(1)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent Ta(2)C6 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. There are four inequivalent C sites. In the first C site, C(1) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form CTa6 octahedra that share corners with three equivalent C(2)Hf3Ta3 octahedra, corners with three equivalent C(4)U3Ta3 octahedra, edges with three equivalent C(2)Hf3Ta3 octahedra, edges with three equivalent C(4)U3Ta3 octahedra, and edges with six equivalent C(1)Ta6 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the second C site, C(2) is bonded to three equivalent Hf(1) and three equivalent Ta(2) atoms to form CHf3Ta3 octahedra that share corners with three equivalent C(3)Hf3U3 octahedra, corners with three equivalent C(1)Ta6 octahedra, edges with three equivalent C(3)Hf3U3 octahedra, edges with three equivalent C(1)Ta6 octahedra, and edges with six equivalent C(2)Hf3Ta3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third C site, C(3) is bonded to three equivalent U(1) and three equivalent Hf(1) atoms to form CHf3U3 octahedra that share corners with three equivalent C(2)Hf3Ta3 octahedra, corners with three equivalent C(4)U3Ta3 octahedra, edges with three equivalent C(2)Hf3Ta3 octahedra, edges with three equivalent C(4)U3Ta3 octahedra, and edges with six equivalent C(3)Hf3U3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth C site, C(4) is bonded to three equivalent U(1) and three equivalent Ta(1) atoms to form CU3Ta3 octahedra that share corners with three equivalent C(3)Hf3U3 octahedra, corners with three equivalent C(1)Ta6 octahedra, edges with three equivalent C(3)Hf3U3 octahedra, edges with three equivalent C(1)Ta6 octahedra, and edges with six equivalent C(4)U3Ta3 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfU(TaC2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.082
_cell_length_b   11.082
_cell_length_c   11.082
_cell_angle_alpha   16.749
_cell_angle_beta   16.749
_cell_angle_gamma   16.749
_symmetry_Int_Tables_number   1
_cell_volume   98.578
_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
  Hf  Hf0  1  0.996  0.996  0.996  1.0
  U  U1  1  0.751  0.751  0.751  1.0
  Ta  Ta2  1  0.504  0.504  0.504  1.0
  Ta  Ta3  1  0.249  0.249  0.249  1.0
  C  C4  1  0.877  0.877  0.877  1.0
  C  C5  1  0.620  0.620  0.620  1.0
  C  C6  1  0.371  0.371  0.371  1.0
  C  C7  1  0.133  0.133  0.133  1.0
[/CIF]
.
The crystal structure described by UHf(TaC2)2 is alpha Po-derived structured and crystallizes in the trigonal R3m space group. U(1) is bonded to three equivalent C(3) and three equivalent C(4) atoms to form UC6 octahedra that share corners with three equivalent Hf(1)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Hf(1)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent U(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. Hf(1) is bonded to three equivalent C(2) and three equivalent C(3) atoms to form HfC6 octahedra that share corners with three equivalent U(1)C6 octahedra, corners with three equivalent Ta(2)C6 octahedra, edges with three equivalent U(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, and edges with six equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent C(1) and three equivalent C(4) atoms to form TaC6 octahedra that share corners with three equivalent U(1)C6 octahedra, corners with three equivalent Ta(2)C6 octahedra, edges with three equivalent U(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, and edges with six equivalent Ta(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the second Ta site, Ta(2) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form TaC6 octahedra that share corners with three equivalent Hf(1)C6 octahedra, corners with three equivalent Ta(1)C6 octahedra, edges with three equivalent Hf(1)C6 octahedra, edges with three equivalent Ta(1)C6 octahedra, and edges with six equivalent Ta(2)C6 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. There are four inequivalent C sites. In the first C site, C(1) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form CTa6 octahedra that share corners with three equivalent C(2)Hf3Ta3 octahedra, corners with three equivalent C(4)U3Ta3 octahedra, edges with three equivalent C(2)Hf3Ta3 octahedra, edges with three equivalent C(4)U3Ta3 octahedra, and edges with six equivalent C(1)Ta6 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the second C site, C(2) is bonded to three equivalent Hf(1) and three equivalent Ta(2) atoms to form CHf3Ta3 octahedra that share corners with three equivalent C(3)Hf3U3 octahedra, corners with three equivalent C(1)Ta6 octahedra, edges with three equivalent C(3)Hf3U3 octahedra, edges with three equivalent C(1)Ta6 octahedra, and edges with six equivalent C(2)Hf3Ta3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third C site, C(3) is bonded to three equivalent U(1) and three equivalent Hf(1) atoms to form CHf3U3 octahedra that share corners with three equivalent C(2)Hf3Ta3 octahedra, corners with three equivalent C(4)U3Ta3 octahedra, edges with three equivalent C(2)Hf3Ta3 octahedra, edges with three equivalent C(4)U3Ta3 octahedra, and edges with six equivalent C(3)Hf3U3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth C site, C(4) is bonded to three equivalent U(1) and three equivalent Ta(1) atoms to form CU3Ta3 octahedra that share corners with three equivalent C(3)Hf3U3 octahedra, corners with three equivalent C(1)Ta6 octahedra, edges with three equivalent C(3)Hf3U3 octahedra, edges with three equivalent C(1)Ta6 octahedra, and edges with six equivalent C(4)U3Ta3 octahedra. The corner-sharing octahedral tilt angles range from 1-2°. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfU(TaC2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.082
_cell_length_b   11.082
_cell_length_c   11.082
_cell_angle_alpha   16.749
_cell_angle_beta   16.749
_cell_angle_gamma   16.749
_symmetry_Int_Tables_number   1
_cell_volume   98.578
_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
  Hf  Hf0  1  0.996  0.996  0.996  1.0
  U  U1  1  0.751  0.751  0.751  1.0
  Ta  Ta2  1  0.504  0.504  0.504  1.0
  Ta  Ta3  1  0.249  0.249  0.249  1.0
  C  C4  1  0.877  0.877  0.877  1.0
  C  C5  1  0.620  0.620  0.620  1.0
  C  C6  1  0.371  0.371  0.371  1.0
  C  C7  1  0.133  0.133  0.133  1.0
[/CIF]
.