data_Na2HfCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.91
_cell_length_b   3.91
_cell_length_c   5.62
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2HfCu
_chemical_formula_sum   'Na2 Hf1 Cu1'
_cell_volume   85.83
_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  Na2  1  0.95  0.0  0.81  1.0
  Na  Na3  1  0.0  0.95  0.81  1.0
  Hf  Hf1  1  0.95  0.95  0.0  1.0
  Cu  Cu0  1  0.0  0.0  0.0  1.0

data_Na2HfCu
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.53
_cell_length_b   5.53
_cell_length_c   5.62
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2HfCu
_chemical_formula_sum   'Na4 Hf2 Cu2'
_cell_volume   171.67
_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  0.48  0.48  0.81  1.0
  Hf  Hf1  2  0.45  0.5  -0.0  1.0
  Cu  Cu2  2  0.0  0.0  0.0  1.0

Na Na Hf Cu
Na2HfCu crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Na2HfCu clusters. Na(1) is bonded in a 3-coordinate geometry to one Na(1), one Hf(1), and one Cu(1) atom. The Na(1)-Na(1) bond length is 0.26 Å. The Na(1)-Hf(1) bond length is 1.08 Å. The Na(1)-Cu(1) bond length is 1.08 Å. Hf(1) is bonded in a single-bond geometry to two equivalent Na(1) and one Cu(1) atom. The Hf(1)-Cu(1) bond length is 0.26 Å. Cu(1) is bonded in a single-bond geometry to two equivalent Na(1) and one Hf(1) atom.