The crystal structure described by NpPa3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded to four equivalent Pa(2) and eight equivalent Pa(1) atoms to form NpPa12 cuboctahedra that share corners with four equivalent Np(1)Pa12 cuboctahedra, corners with eight equivalent Pa(2)Np4Pa8 cuboctahedra, edges with eight equivalent Np(1)Pa12 cuboctahedra, edges with sixteen equivalent Pa(1)Np4Pa8 cuboctahedra, faces with four equivalent Np(1)Pa12 cuboctahedra, faces with six equivalent Pa(2)Np4Pa8 cuboctahedra, and faces with eight equivalent Pa(1)Np4Pa8 cuboctahedra. There are two inequivalent Pa sites. In the first Pa site, Pa(1) is bonded to four equivalent Np(1), four equivalent Pa(1), and four equivalent Pa(2) atoms to form PaNp4Pa8 cuboctahedra that share corners with twelve equivalent Pa(1)Np4Pa8 cuboctahedra, edges with eight equivalent Np(1)Pa12 cuboctahedra, edges with eight equivalent Pa(1)Np4Pa8 cuboctahedra, edges with eight equivalent Pa(2)Np4Pa8 cuboctahedra, faces with four equivalent Np(1)Pa12 cuboctahedra, faces with four equivalent Pa(2)Np4Pa8 cuboctahedra, and faces with ten equivalent Pa(1)Np4Pa8 cuboctahedra. In the second Pa site, Pa(2) is bonded to four equivalent Np(1) and eight equivalent Pa(1) atoms to form distorted PaNp4Pa8 cuboctahedra that share corners with four equivalent Pa(2)Np4Pa8 cuboctahedra, corners with eight equivalent Np(1)Pa12 cuboctahedra, edges with eight equivalent Pa(2)Np4Pa8 cuboctahedra, edges with sixteen equivalent Pa(1)Np4Pa8 cuboctahedra, faces with four equivalent Pa(2)Np4Pa8 cuboctahedra, faces with six equivalent Np(1)Pa12 cuboctahedra, and faces with eight equivalent Pa(1)Np4Pa8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_NpPa3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.822
_cell_length_b   5.822
_cell_length_c   5.822
_cell_angle_alpha   136.381
_cell_angle_beta   136.381
_cell_angle_gamma   63.391
_symmetry_Int_Tables_number   1
_cell_volume   92.693
_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
  Np  Np0  1  0.000  0.000  0.000  1.0
  Pa  Pa1  1  0.750  0.250  0.500  1.0
  Pa  Pa2  1  0.250  0.750  0.500  1.0
  Pa  Pa3  1  0.500  0.500  0.000  1.0
[/CIF]
.
The crystal structure described by NpPa3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded to four equivalent Pa(2) and eight equivalent Pa(1) atoms to form NpPa12 cuboctahedra that share corners with four equivalent Np(1)Pa12 cuboctahedra, corners with eight equivalent Pa(2)Np4Pa8 cuboctahedra, edges with eight equivalent Np(1)Pa12 cuboctahedra, edges with sixteen equivalent Pa(1)Np4Pa8 cuboctahedra, faces with four equivalent Np(1)Pa12 cuboctahedra, faces with six equivalent Pa(2)Np4Pa8 cuboctahedra, and faces with eight equivalent Pa(1)Np4Pa8 cuboctahedra. There are two inequivalent Pa sites. In the first Pa site, Pa(1) is bonded to four equivalent Np(1), four equivalent Pa(1), and four equivalent Pa(2) atoms to form PaNp4Pa8 cuboctahedra that share corners with twelve equivalent Pa(1)Np4Pa8 cuboctahedra, edges with eight equivalent Np(1)Pa12 cuboctahedra, edges with eight equivalent Pa(1)Np4Pa8 cuboctahedra, edges with eight equivalent Pa(2)Np4Pa8 cuboctahedra, faces with four equivalent Np(1)Pa12 cuboctahedra, faces with four equivalent Pa(2)Np4Pa8 cuboctahedra, and faces with ten equivalent Pa(1)Np4Pa8 cuboctahedra. In the second Pa site, Pa(2) is bonded to four equivalent Np(1) and eight equivalent Pa(1) atoms to form distorted PaNp4Pa8 cuboctahedra that share corners with four equivalent Pa(2)Np4Pa8 cuboctahedra, corners with eight equivalent Np(1)Pa12 cuboctahedra, edges with eight equivalent Pa(2)Np4Pa8 cuboctahedra, edges with sixteen equivalent Pa(1)Np4Pa8 cuboctahedra, faces with four equivalent Pa(2)Np4Pa8 cuboctahedra, faces with six equivalent Np(1)Pa12 cuboctahedra, and faces with eight equivalent Pa(1)Np4Pa8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_NpPa3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.822
_cell_length_b   5.822
_cell_length_c   5.822
_cell_angle_alpha   136.381
_cell_angle_beta   136.381
_cell_angle_gamma   63.391
_symmetry_Int_Tables_number   1
_cell_volume   92.693
_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
  Np  Np0  1  0.000  0.000  0.000  1.0
  Pa  Pa1  1  0.750  0.250  0.500  1.0
  Pa  Pa2  1  0.250  0.750  0.500  1.0
  Pa  Pa3  1  0.500  0.500  0.000  1.0
[/CIF]
.