data_Na2PuNb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.1
_cell_length_b   5.1
_cell_length_c   5.1
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2PuNb
_chemical_formula_sum   'Na2 Pu1 Nb1'
_cell_volume   93.58
_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
  Na  Na0  1  0.8  0.8  0.8  1.0
  Na  Na1  1  0.41  0.41  0.41  1.0
  Pu  Pu3  1  0.6  0.6  0.6  1.0
  Nb  Nb2  1  0.0  0.0  0.0  1.0

data_Na2PuNb
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.1
_cell_length_b   5.1
_cell_length_c   12.48
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na2PuNb
_chemical_formula_sum   'Na6 Pu3 Nb3'
_cell_volume   280.73
_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
  Na  Na0  3  0.0  0.0  0.2  1.0
  Na  Na1  3  0.0  0.0  0.59  1.0
  Pu  Pu2  3  0.0  0.0  0.4  1.0
  Nb  Nb3  3  0.0  0.0  0.0  1.0

Na Na Pu Nb
Na2PuNb crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a linear geometry to one Pu(1) and one Nb(1) atom. The Na(1)-Pu(1) bond length is 2.48 Å. The Na(1)-Nb(1) bond length is 2.48 Å. In the second Na site, Na(2) is bonded to one Pu(1) and three equivalent Nb(1) atoms to form distorted corner-sharing NaPuNb3 tetrahedra. The Na(2)-Pu(1) bond length is 2.48 Å. All Na(2)-Nb(1) bond lengths are 3.08 Å. Pu(1) is bonded in a 2-coordinate geometry to one Na(1) and one Na(2) atom. Nb(1) is bonded in a 1-coordinate geometry to one Na(1) and three equivalent Na(2) atoms.