data_PrU2Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   5.2
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PrU2Al
_chemical_formula_sum   'Pr1 U2 Al1'
_cell_volume   99.26
_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
  Pr  Pr1  1  0.67  0.67  0.67  1.0
  U  U2  1  0.84  0.84  0.84  1.0
  U  U3  1  0.51  0.51  0.51  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_PrU2Al
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   12.73
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   PrU2Al
_chemical_formula_sum   'Pr3 U6 Al3'
_cell_volume   297.79
_cell_formula_units_Z   3
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
  Pr  Pr0  3  0.0  0.0  0.33  1.0
  U  U1  3  0.0  0.0  0.16  1.0
  U  U2  3  0.0  0.0  0.49  1.0
  Al  Al3  3  0.0  0.0  -0.0  1.0

Pr U U Al
U2PrAl crystallizes in the trigonal R3m space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a linear geometry to one Pr(1) and one Al(1) atom. The U(1)-Pr(1) bond length is 2.07 Å. The U(1)-Al(1) bond length is 2.07 Å. In the second U site, U(2) is bonded in a single-bond geometry to one Pr(1) atom. The U(2)-Pr(1) bond length is 2.07 Å. Pr(1) is bonded to one U(1), one U(2), and three equivalent Al(1) atoms to form distorted PrU2Al3 trigonal bipyramids that share corners with six equivalent Pr(1)U2Al3 trigonal bipyramids and  a cornercorner with one Al(1)Pr3U trigonal pyramid. All Pr(1)-Al(1) bond lengths are 3.00 Å. Al(1) is bonded to one U(1) and three equivalent Pr(1) atoms to form distorted AlPr3U trigonal pyramids that share  a cornercorner with one Pr(1)U2Al3 trigonal bipyramid and corners with six equivalent Al(1)Pr3U trigonal pyramids.