data_NaFe2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.27
_cell_length_b   9.27
_cell_length_c   9.27
_cell_angle_alpha   17.61
_cell_angle_beta   17.61
_cell_angle_gamma   17.61
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaFe2As
_chemical_formula_sum   'Na1 Fe2 As1'
_cell_volume   63.58
_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  Na3  1  0.0  0.0  0.0  1.0
  Fe  Fe1  1  0.0  0.0  0.86  1.0
  Fe  Fe2  1  0.0  0.0  0.51  1.0
  As  As0  1  0.0  0.0  0.68  1.0

data_NaFe2As
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.91
_cell_length_b   2.84
_cell_length_c   9.27
_cell_angle_alpha   90.0
_cell_angle_beta   100.18
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaFe2As
_chemical_formula_sum   'Na2 Fe4 As2'
_cell_volume   127.16
_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  2  0.0  0.0  0.0  1.0
  Fe  Fe1  2  0.0  0.0  0.14  1.0
  Fe  Fe2  2  0.0  0.0  0.49  1.0
  As  As3  2  0.0  0.0  0.32  1.0

Na Fe Fe As
Na Fe Fe As 0 1 o o - 1 3 o o o 2 3 o o o 
NaFe2As is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two NaFe2As clusters. Na(1) is bonded in a single-bond geometry to one Fe(1) atom. The Na(1)-Fe(1) bond length is 1.28 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted linear geometry to one Na(1) and one As(1) atom. The Fe(1)-As(1) bond length is 1.64 Å. In the second Fe site, Fe(2) is bonded in a single-bond geometry to one As(1) atom. The Fe(2)-As(1) bond length is 1.64 Å. As(1) is bonded in a linear geometry to one Fe(1) and one Fe(2) atom.