data_Na3As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.06
_cell_length_b   5.06
_cell_length_c   5.06
_cell_angle_alpha   120.91
_cell_angle_beta   120.91
_cell_angle_gamma   88.44
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na3As
_chemical_formula_sum   'Na3 As1'
_cell_volume   90.48
_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
  Na  Na1  1  0.5  0.0  0.81  1.0
  Na  Na2  1  0.0  0.0  0.0  1.0
  Na  Na3  1  0.0  0.5  0.81  1.0
  As  As0  1  0.0  0.0  0.63  1.0

data_Na3As
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.06
_cell_length_b   7.06
_cell_length_c   5.06
_cell_angle_alpha   90.0
_cell_angle_beta   134.22
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na3As
_chemical_formula_sum   'Na6 As2'
_cell_volume   180.96
_cell_formula_units_Z   2
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
  Na  Na0  4  0.25  0.25  0.32  1.0
  Na  Na1  2  0.0  0.0  0.0  1.0
  As  As2  2  0.0  0.0  0.63  1.0

Na Na Na As
Na3As is Copper structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two sodium arsenide (na3as) molecules. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted single-bond geometry to one As(1) atom. The Na(1)-As(1) bond length is 2.19 Å. In the second Na site, Na(2) is bonded in a single-bond geometry to one As(1) atom. The Na(2)-As(1) bond length is 1.88 Å. As(1) is bonded in a distorted trigonal non-coplanar geometry to one Na(2) and two equivalent Na(1) atoms.