data_NaHf4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.72
_cell_length_b   7.72
_cell_length_c   7.72
_cell_angle_alpha   148.29
_cell_angle_beta   148.29
_cell_angle_gamma   45.46
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaHf4
_chemical_formula_sum   'Na1 Hf4'
_cell_volume   126.72
_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  Na4  1  0.0  0.0  0.0  1.0
  Hf  Hf0  1  0.0  0.11  0.56  1.0
  Hf  Hf1  1  0.11  0.0  0.56  1.0
  Hf  Hf2  1  0.0  0.0  0.69  1.0
  Hf  Hf3  1  0.0  0.0  0.55  1.0

data_NaHf4
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.97
_cell_length_b   5.97
_cell_length_c   7.72
_cell_angle_alpha   90.0
_cell_angle_beta   112.73
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaHf4
_chemical_formula_sum   'Na2 Hf8'
_cell_volume   253.44
_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
  Hf  Hf1  4  0.05  0.05  0.55  1.0
  Hf  Hf2  2  0.0  0.0  0.31  1.0
  Hf  Hf3  2  0.0  0.0  0.45  1.0

Na Hf Hf Hf Hf
NaHf4 is Indium-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two NaHf4 clusters. Na(1) is bonded in a single-bond geometry to one Hf(2) atom. The Na(1)-Hf(2) bond length is 2.39 Å. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 2-coordinate geometry to one Hf(1) and one Hf(3) atom. The Hf(1)-Hf(1) bond length is 0.65 Å. The Hf(1)-Hf(3) bond length is 0.79 Å. In the second Hf site, Hf(2) is bonded in a linear geometry to one Na(1) and one Hf(3) atom. The Hf(2)-Hf(3) bond length is 1.07 Å. In the third Hf site, Hf(3) is bonded in a 3-coordinate geometry to one Hf(2) and two equivalent Hf(1) atoms.