The material described by Np3Th is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to four equivalent Np(1), four equivalent Np(2), and four equivalent Th(1) atoms to form NpTh4Np8 cuboctahedra that share corners with twelve equivalent Np(1)Th4Np8 cuboctahedra, edges with eight equivalent Np(1)Th4Np8 cuboctahedra, edges with eight equivalent Np(2)Th4Np8 cuboctahedra, edges with eight equivalent Th(1)Np12 cuboctahedra, faces with four equivalent Np(2)Th4Np8 cuboctahedra, faces with four equivalent Th(1)Np12 cuboctahedra, and faces with ten equivalent Np(1)Th4Np8 cuboctahedra. In the second Np site, Np(2) is bonded to eight equivalent Np(1) and four equivalent Th(1) atoms to form NpTh4Np8 cuboctahedra that share corners with four equivalent Np(2)Th4Np8 cuboctahedra, corners with eight equivalent Th(1)Np12 cuboctahedra, edges with eight equivalent Np(2)Th4Np8 cuboctahedra, edges with sixteen equivalent Np(1)Th4Np8 cuboctahedra, faces with four equivalent Np(2)Th4Np8 cuboctahedra, faces with six equivalent Th(1)Np12 cuboctahedra, and faces with eight equivalent Np(1)Th4Np8 cuboctahedra. Th(1) is bonded to four equivalent Np(2) and eight equivalent Np(1) atoms to form ThNp12 cuboctahedra that share corners with four equivalent Th(1)Np12 cuboctahedra, corners with eight equivalent Np(2)Th4Np8 cuboctahedra, edges with eight equivalent Th(1)Np12 cuboctahedra, edges with sixteen equivalent Np(1)Th4Np8 cuboctahedra, faces with four equivalent Th(1)Np12 cuboctahedra, faces with six equivalent Np(2)Th4Np8 cuboctahedra, and faces with eight equivalent Np(1)Th4Np8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_ThNp3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.525
_cell_length_b   5.525
_cell_length_c   5.525
_cell_angle_alpha   130.825
_cell_angle_beta   130.825
_cell_angle_gamma   72.091
_symmetry_Int_Tables_number   1
_cell_volume   94.443
_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
  Th  Th0  1  0.000  0.000  0.000  1.0
  Np  Np1  1  0.750  0.250  0.500  1.0
  Np  Np2  1  0.250  0.750  0.500  1.0
  Np  Np3  1  0.500  0.500  0.000  1.0
[/CIF]
.
The material described by Np3Th is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to four equivalent Np(1), four equivalent Np(2), and four equivalent Th(1) atoms to form NpTh4Np8 cuboctahedra that share corners with twelve equivalent Np(1)Th4Np8 cuboctahedra, edges with eight equivalent Np(1)Th4Np8 cuboctahedra, edges with eight equivalent Np(2)Th4Np8 cuboctahedra, edges with eight equivalent Th(1)Np12 cuboctahedra, faces with four equivalent Np(2)Th4Np8 cuboctahedra, faces with four equivalent Th(1)Np12 cuboctahedra, and faces with ten equivalent Np(1)Th4Np8 cuboctahedra. In the second Np site, Np(2) is bonded to eight equivalent Np(1) and four equivalent Th(1) atoms to form NpTh4Np8 cuboctahedra that share corners with four equivalent Np(2)Th4Np8 cuboctahedra, corners with eight equivalent Th(1)Np12 cuboctahedra, edges with eight equivalent Np(2)Th4Np8 cuboctahedra, edges with sixteen equivalent Np(1)Th4Np8 cuboctahedra, faces with four equivalent Np(2)Th4Np8 cuboctahedra, faces with six equivalent Th(1)Np12 cuboctahedra, and faces with eight equivalent Np(1)Th4Np8 cuboctahedra. Th(1) is bonded to four equivalent Np(2) and eight equivalent Np(1) atoms to form ThNp12 cuboctahedra that share corners with four equivalent Th(1)Np12 cuboctahedra, corners with eight equivalent Np(2)Th4Np8 cuboctahedra, edges with eight equivalent Th(1)Np12 cuboctahedra, edges with sixteen equivalent Np(1)Th4Np8 cuboctahedra, faces with four equivalent Th(1)Np12 cuboctahedra, faces with six equivalent Np(2)Th4Np8 cuboctahedra, and faces with eight equivalent Np(1)Th4Np8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_ThNp3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.525
_cell_length_b   5.525
_cell_length_c   5.525
_cell_angle_alpha   130.825
_cell_angle_beta   130.825
_cell_angle_gamma   72.091
_symmetry_Int_Tables_number   1
_cell_volume   94.443
_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
  Th  Th0  1  0.000  0.000  0.000  1.0
  Np  Np1  1  0.750  0.250  0.500  1.0
  Np  Np2  1  0.250  0.750  0.500  1.0
  Np  Np3  1  0.500  0.500  0.000  1.0
[/CIF]
.