data_PuNi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.89
_cell_length_b   4.89
_cell_length_c   4.89
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PuNi2
_chemical_formula_sum   'Pu2 Ni4'
_cell_volume   82.51
_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
  Pu  Pu4  1  0.0  0.0  0.0  1.0
  Pu  Pu5  1  0.73  0.73  0.73  1.0
  Ni  Ni0  1  0.59  0.59  0.32  1.0
  Ni  Ni1  1  0.59  0.32  0.59  1.0
  Ni  Ni2  1  0.32  0.59  0.59  1.0
  Ni  Ni3  1  0.32  0.32  0.32  1.0

data_PuNi2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.89
_cell_length_b   4.89
_cell_length_c   11.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   PuNi2
_chemical_formula_sum   'Pu6 Ni12'
_cell_volume   247.54
_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
  Pu  Pu0  3  0.0  0.0  0.0  1.0
  Pu  Pu1  3  0.0  0.0  0.27  1.0
  Ni  Ni2  9  0.18  0.09  0.5  1.0
  Ni  Ni3  3  0.0  0.0  0.68  1.0

Pu Pu Ni Ni Ni Ni
PuNi2 crystallizes in the trigonal R3m space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded in a 6-coordinate geometry to three equivalent Ni(1) and three equivalent Ni(2) atoms. All Pu(1)-Ni(1) bond lengths are 2.86 Å. All Pu(1)-Ni(2) bond lengths are 2.83 Å. In the second Pu site, Pu(2) is bonded in a 3-coordinate geometry to three equivalent Ni(1) and three equivalent Ni(2) atoms. All Pu(2)-Ni(1) bond lengths are 2.42 Å. All Pu(2)-Ni(2) bond lengths are 2.96 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one Pu(1), one Pu(2), one Ni(2), and two equivalent Ni(1) atoms. The Ni(1)-Ni(2) bond length is 2.30 Å. Both Ni(1)-Ni(1) bond lengths are 1.33 Å. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Pu(1), three equivalent Pu(2), and three equivalent Ni(1) atoms.