The material described by Np3Zr 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 Zr(1) atoms to form NpZr4Np8 cuboctahedra that share corners with twelve equivalent Np(1)Zr4Np8 cuboctahedra, edges with eight equivalent Np(1)Zr4Np8 cuboctahedra, edges with eight equivalent Np(2)Zr4Np8 cuboctahedra, edges with eight equivalent Zr(1)Np12 cuboctahedra, faces with four equivalent Np(2)Zr4Np8 cuboctahedra, faces with four equivalent Zr(1)Np12 cuboctahedra, and faces with ten equivalent Np(1)Zr4Np8 cuboctahedra. In the second Np site, Np(2) is bonded to eight equivalent Np(1) and four equivalent Zr(1) atoms to form NpZr4Np8 cuboctahedra that share corners with four equivalent Np(2)Zr4Np8 cuboctahedra, corners with eight equivalent Zr(1)Np12 cuboctahedra, edges with eight equivalent Np(2)Zr4Np8 cuboctahedra, edges with sixteen equivalent Np(1)Zr4Np8 cuboctahedra, faces with four equivalent Np(2)Zr4Np8 cuboctahedra, faces with six equivalent Zr(1)Np12 cuboctahedra, and faces with eight equivalent Np(1)Zr4Np8 cuboctahedra. Zr(1) is bonded to four equivalent Np(2) and eight equivalent Np(1) atoms to form ZrNp12 cuboctahedra that share corners with four equivalent Zr(1)Np12 cuboctahedra, corners with eight equivalent Np(2)Zr4Np8 cuboctahedra, edges with eight equivalent Zr(1)Np12 cuboctahedra, edges with sixteen equivalent Np(1)Zr4Np8 cuboctahedra, faces with four equivalent Zr(1)Np12 cuboctahedra, faces with six equivalent Np(2)Zr4Np8 cuboctahedra, and faces with eight equivalent Np(1)Zr4Np8 cuboctahedra. is represented by the CIF file [CIF]
data_ZrNp3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.585
_cell_length_b   5.585
_cell_length_c   5.585
_cell_angle_alpha   134.346
_cell_angle_beta   134.346
_cell_angle_gamma   66.549
_symmetry_Int_Tables_number   1
_cell_volume   87.678
_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
  Zr  Zr0  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 Np3Zr 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 Zr(1) atoms to form NpZr4Np8 cuboctahedra that share corners with twelve equivalent Np(1)Zr4Np8 cuboctahedra, edges with eight equivalent Np(1)Zr4Np8 cuboctahedra, edges with eight equivalent Np(2)Zr4Np8 cuboctahedra, edges with eight equivalent Zr(1)Np12 cuboctahedra, faces with four equivalent Np(2)Zr4Np8 cuboctahedra, faces with four equivalent Zr(1)Np12 cuboctahedra, and faces with ten equivalent Np(1)Zr4Np8 cuboctahedra. In the second Np site, Np(2) is bonded to eight equivalent Np(1) and four equivalent Zr(1) atoms to form NpZr4Np8 cuboctahedra that share corners with four equivalent Np(2)Zr4Np8 cuboctahedra, corners with eight equivalent Zr(1)Np12 cuboctahedra, edges with eight equivalent Np(2)Zr4Np8 cuboctahedra, edges with sixteen equivalent Np(1)Zr4Np8 cuboctahedra, faces with four equivalent Np(2)Zr4Np8 cuboctahedra, faces with six equivalent Zr(1)Np12 cuboctahedra, and faces with eight equivalent Np(1)Zr4Np8 cuboctahedra. Zr(1) is bonded to four equivalent Np(2) and eight equivalent Np(1) atoms to form ZrNp12 cuboctahedra that share corners with four equivalent Zr(1)Np12 cuboctahedra, corners with eight equivalent Np(2)Zr4Np8 cuboctahedra, edges with eight equivalent Zr(1)Np12 cuboctahedra, edges with sixteen equivalent Np(1)Zr4Np8 cuboctahedra, faces with four equivalent Zr(1)Np12 cuboctahedra, faces with six equivalent Np(2)Zr4Np8 cuboctahedra, and faces with eight equivalent Np(1)Zr4Np8 cuboctahedra. is represented by the CIF file [CIF]
data_ZrNp3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.585
_cell_length_b   5.585
_cell_length_c   5.585
_cell_angle_alpha   134.346
_cell_angle_beta   134.346
_cell_angle_gamma   66.549
_symmetry_Int_Tables_number   1
_cell_volume   87.678
_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
  Zr  Zr0  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]
.