The material structure described by NpSi crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. In the second Np site, Np(2) is bonded in a 8-coordinate geometry to eight equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to three equivalent Np(1), four equivalent Np(2), and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_NpSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.417
_cell_length_b   6.417
_cell_length_c   6.376
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   141.035
_symmetry_Int_Tables_number   1
_cell_volume   165.129
_cell_formula_units_Z   4
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  0.272  0.728  0.250  1.0
  Np  Np1  1  0.728  0.272  0.750  1.0
  Np  Np2  1  0.444  0.556  0.750  1.0
  Np  Np3  1  0.556  0.444  0.250  1.0
  Si  Si4  1  0.096  0.904  0.559  1.0
  Si  Si5  1  0.904  0.096  0.441  1.0
  Si  Si6  1  0.096  0.904  0.941  1.0
  Si  Si7  1  0.904  0.096  0.059  1.0
[/CIF]
.
The material structure described by NpSi crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. In the second Np site, Np(2) is bonded in a 8-coordinate geometry to eight equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to three equivalent Np(1), four equivalent Np(2), and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_NpSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.417
_cell_length_b   6.417
_cell_length_c   6.376
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   141.035
_symmetry_Int_Tables_number   1
_cell_volume   165.129
_cell_formula_units_Z   4
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  0.272  0.728  0.250  1.0
  Np  Np1  1  0.728  0.272  0.750  1.0
  Np  Np2  1  0.444  0.556  0.750  1.0
  Np  Np3  1  0.556  0.444  0.250  1.0
  Si  Si4  1  0.096  0.904  0.559  1.0
  Si  Si5  1  0.904  0.096  0.441  1.0
  Si  Si6  1  0.096  0.904  0.941  1.0
  Si  Si7  1  0.904  0.096  0.059  1.0
[/CIF]
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