data_NpAsS
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.86
_cell_length_b   3.86
_cell_length_c   8.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NpAsS
_chemical_formula_sum   'Np2 As2 S2'
_cell_volume   121.1
_cell_formula_units_Z   2
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  Np2  1  0.0  0.93  0.39  1.0
  Np  Np3  1  0.93  0.0  0.76  1.0
  As  As0  1  0.0  0.0  0.0  1.0
  As  As1  1  0.93  0.93  0.0  1.0
  S  S4  1  0.93  0.0  0.95  1.0
  S  S5  1  0.0  0.93  0.19  1.0

data_NpAsS
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.45
_cell_length_b   5.45
_cell_length_c   8.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NpAsS
_chemical_formula_sum   'Np4 As4 S4'
_cell_volume   242.2
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.39  1.0
  Np  Np1  2  0.43  0.5  0.76  1.0
  As  As2  4  0.46  0.46  0.0  1.0
  S  S3  2  0.0  0.0  0.19  1.0
  S  S4  2  0.43  0.5  0.95  1.0

Np Np As As S S
Np Np As As S S 0 5 o o o 1 4 o o o 2 3 - - o 2 4 - o - 2 5 o - o 3 4 o + - 3 5 + o o 
NpAsS crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two NpAsS clusters. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded in a single-bond geometry to one S(2) atom. The Np(1)-S(2) bond length is 1.60 Å. In the second Np site, Np(2) is bonded in a single-bond geometry to one S(1) atom. The Np(2)-S(1) bond length is 1.60 Å. As(1) is bonded in a 2-coordinate geometry to one As(1), one S(1), and one S(2) atom. The As(1)-As(1) bond length is 0.39 Å. The As(1)-S(1) bond length is 0.47 Å. The As(1)-S(2) bond length is 1.57 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one Np(2) and two equivalent As(1) atoms. In the second S site, S(2) is bonded in a distorted single-bond geometry to one Np(1) and two equivalent As(1) atoms.