data_Tb3Np
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.94
_cell_length_b   4.94
_cell_length_c   4.94
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tb3Np
_chemical_formula_sum   'Tb3 Np1'
_cell_volume   120.73
_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
  Tb  Tb0  1  0.0  0.47  0.47  1.0
  Tb  Tb1  1  0.47  0.0  0.47  1.0
  Tb  Tb2  1  0.47  0.47  0.0  1.0
  Np  Np3  1  0.0  0.0  0.0  1.0

data_Tb3Np
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.99
_cell_length_b   6.99
_cell_length_c   8.56
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Tb3Np
_chemical_formula_sum   'Tb9 Np3'
_cell_volume   362.2
_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
  Tb  Tb0  9  0.02  0.51  0.98  1.0
  Np  Np1  3  0.0  0.0  0.0  1.0

Tb Tb Tb Np
Tb Tb Tb Np 0 1 - o o 0 1 - + o 0 1 o o o 0 1 o + o 0 2 - o o 0 2 - o + 0 2 o o o 0 2 o o + 0 3 o o o 0 3 o o + 0 3 o + o 0 3 o + + 1 3 o o o 1 3 o o + 1 3 + o o 1 3 + o + 1 2 o - o 1 2 o - + 1 2 o o o 1 2 o o + 2 3 o o o 2 3 o + o 2 3 + o o 2 3 + + o 
NpTb3 is Uranium Silicide structured and crystallizes in the trigonal R3m space group. Np(1) is bonded to twelve equivalent Tb(1) atoms to form NpTb12 cuboctahedra that share corners with twelve equivalent Np(1)Tb12 cuboctahedra, edges with twenty-four equivalent Tb(1)Tb8Np4 cuboctahedra, faces with six equivalent Np(1)Tb12 cuboctahedra, and faces with twelve equivalent Tb(1)Tb8Np4 cuboctahedra. There are a spread of Np(1)-Tb(1) bond distances ranging from 3.29-3.70 Å. Tb(1) is bonded to four equivalent Np(1) and eight equivalent Tb(1) atoms to form distorted TbTb8Np4 cuboctahedra that share corners with twelve equivalent Tb(1)Tb8Np4 cuboctahedra, edges with eight equivalent Np(1)Tb12 cuboctahedra, edges with sixteen equivalent Tb(1)Tb8Np4 cuboctahedra, faces with four equivalent Np(1)Tb12 cuboctahedra, and faces with fourteen equivalent Tb(1)Tb8Np4 cuboctahedra. There are a spread of Tb(1)-Tb(1) bond distances ranging from 3.29-3.70 Å.