The material described by NpAs2 crystallizes in the tetragonal P4/nmm space group. Np(1) is bonded in a 9-coordinate geometry to four equivalent As(2) and five equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to five equivalent Np(1) atoms to form a mixture of distorted corner and edge-sharing AsNp5 square pyramids. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Np(1) and four equivalent As(2) atoms. is represented by the CIF card [CIF]
data_NpAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.991
_cell_length_b   3.992
_cell_length_c   8.230
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   131.121
_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  Np0  1  0.750  0.750  0.716  1.0
  Np  Np1  1  0.250  0.250  0.284  1.0
  As  As2  1  0.750  0.750  0.359  1.0
  As  As3  1  0.250  0.250  0.641  1.0
  As  As4  1  0.250  0.750  0.000  1.0
  As  As5  1  0.750  0.250  0.000  1.0
[/CIF]
.
The material described by NpAs2 crystallizes in the tetragonal P4/nmm space group. Np(1) is bonded in a 9-coordinate geometry to four equivalent As(2) and five equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to five equivalent Np(1) atoms to form a mixture of distorted corner and edge-sharing AsNp5 square pyramids. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Np(1) and four equivalent As(2) atoms. is represented by the CIF card [CIF]
data_NpAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.991
_cell_length_b   3.992
_cell_length_c   8.230
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   131.121
_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  Np0  1  0.750  0.750  0.716  1.0
  Np  Np1  1  0.250  0.250  0.284  1.0
  As  As2  1  0.750  0.750  0.359  1.0
  As  As3  1  0.250  0.250  0.641  1.0
  As  As4  1  0.250  0.750  0.000  1.0
  As  As5  1  0.750  0.250  0.000  1.0
[/CIF]
.