The material described by NpAs3 crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded to four equivalent As(2) and eight equivalent As(1) atoms to form a mixture of corner, edge, and face-sharing NpAs12 cuboctahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to four equivalent Np(1) and four equivalent As(1) atoms. In the second As site, As(2) is bonded in a square co-planar geometry to four equivalent Np(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_NpAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.638
_cell_length_b   5.638
_cell_length_c   5.638
_cell_angle_alpha   138.012
_cell_angle_beta   138.012
_cell_angle_gamma   60.885
_symmetry_Int_Tables_number   1
_cell_volume   79.342
_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
  As  As1  1  0.750  0.250  0.500  1.0
  As  As2  1  0.250  0.750  0.500  1.0
  As  As3  1  0.500  0.500  0.000  1.0
[/CIF]
.
The material described by NpAs3 crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded to four equivalent As(2) and eight equivalent As(1) atoms to form a mixture of corner, edge, and face-sharing NpAs12 cuboctahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to four equivalent Np(1) and four equivalent As(1) atoms. In the second As site, As(2) is bonded in a square co-planar geometry to four equivalent Np(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_NpAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.638
_cell_length_b   5.638
_cell_length_c   5.638
_cell_angle_alpha   138.012
_cell_angle_beta   138.012
_cell_angle_gamma   60.885
_symmetry_Int_Tables_number   1
_cell_volume   79.342
_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
  As  As1  1  0.750  0.250  0.500  1.0
  As  As2  1  0.250  0.750  0.500  1.0
  As  As3  1  0.500  0.500  0.000  1.0
[/CIF]
.