The material described by Np2Si3 crystallizes in the hexagonal P-6m2 space group. Np(1) is bonded in a 9-coordinate geometry to three equivalent Si(1), three equivalent Si(2), and three equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Np(1) and three equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to six equivalent Np(1) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to six equivalent Np(1) and three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Np2Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.224
_cell_length_b   4.220
_cell_length_c   6.410
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.990
_symmetry_Int_Tables_number   1
_cell_volume   98.965
_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  1.000  1.000  0.023  1.0
  Np  Np1  1  1.000  1.000  0.477  1.0
  Si  Si2  1  0.333  0.666  0.750  1.0
  Si  Si3  1  0.667  0.333  0.250  1.0
  Si  Si4  1  0.668  0.334  0.750  1.0
[/CIF]
.
The material described by Np2Si3 crystallizes in the hexagonal P-6m2 space group. Np(1) is bonded in a 9-coordinate geometry to three equivalent Si(1), three equivalent Si(2), and three equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Np(1) and three equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to six equivalent Np(1) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to six equivalent Np(1) and three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Np2Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.224
_cell_length_b   4.220
_cell_length_c   6.410
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.990
_symmetry_Int_Tables_number   1
_cell_volume   98.965
_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  1.000  1.000  0.023  1.0
  Np  Np1  1  1.000  1.000  0.477  1.0
  Si  Si2  1  0.333  0.666  0.750  1.0
  Si  Si3  1  0.667  0.333  0.250  1.0
  Si  Si4  1  0.668  0.334  0.750  1.0
[/CIF]
.