data_HfU2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.9
_cell_length_b   6.9
_cell_length_c   6.9
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfU2O4
_chemical_formula_sum   'Hf2 U4 O8'
_cell_volume   232.7
_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
  Hf  Hf0  1  0.0  0.0  0.0  1.0
  Hf  Hf1  1  0.44  0.44  0.44  1.0
  U  U10  1  0.66  0.66  0.1  1.0
  U  U11  1  0.1  0.1  0.1  1.0
  U  U12  1  0.66  0.1  0.66  1.0
  U  U13  1  0.1  0.66  0.66  1.0
  O  O2  1  0.02  0.02  0.63  1.0
  O  O3  1  0.57  0.57  0.57  1.0
  O  O4  1  0.57  0.19  0.19  1.0
  O  O5  1  0.19  0.57  0.19  1.0
  O  O6  1  0.02  0.63  0.02  1.0
  O  O7  1  0.63  0.02  0.02  1.0
  O  O8  1  0.63  0.63  0.63  1.0
  O  O9  1  0.19  0.19  0.57  1.0

data_HfU2O4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.9
_cell_length_b   6.9
_cell_length_c   16.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   HfU2O4
_chemical_formula_sum   'Hf6 U12 O24'
_cell_volume   698.11
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Hf  Hf1  3  0.0  0.0  0.56  1.0
  U  U2  9  0.04  0.52  0.86  1.0
  U  U3  3  0.0  0.0  0.9  1.0
  O  O4  9  0.08  0.54  0.35  1.0
  O  O5  9  0.21  0.41  0.78  1.0
  O  O6  3  0.0  0.0  0.37  1.0
  O  O7  3  0.0  0.0  0.43  1.0

Hf Hf U U U U O O O O O O O O
U2HfO4 crystallizes in the trigonal R3m space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 2-coordinate geometry to one Hf(2), one O(2), and two equivalent O(1) atoms. The U(1)-Hf(2) bond length is 2.30 Å. The U(1)-O(2) bond length is 2.79 Å. Both U(1)-O(1) bond lengths are 2.12 Å. In the second U site, U(2) is bonded in a 4-coordinate geometry to one Hf(1) and three equivalent O(1) atoms. The U(2)-Hf(1) bond length is 1.73 Å. All U(2)-O(1) bond lengths are 3.16 Å. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a distorted hexagonal pyramidal geometry to one U(2), three equivalent O(1), and three equivalent O(3) atoms. All Hf(1)-O(1) bond lengths are 2.45 Å. All Hf(1)-O(3) bond lengths are 2.47 Å. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to three equivalent U(1), one O(2), and three equivalent O(3) atoms. The Hf(2)-O(2) bond length is 2.25 Å. All Hf(2)-O(3) bond lengths are 2.58 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one U(2), two equivalent U(1), one Hf(1), and one O(3) atom. The O(1)-O(3) bond length is 1.89 Å. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent U(1), one Hf(2), and one O(4) atom. The O(2)-O(4) bond length is 0.96 Å. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Hf(1), one Hf(2), and one O(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one O(2) atom.