data_Na2Ge
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.29
_cell_length_b   5.21
_cell_length_c   10.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2Ge
_chemical_formula_sum   'Na8 Ge4'
_cell_volume   280.27
_cell_formula_units_Z   4
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  0.37  0.3  0.37  1.0
  Na  Na5  1  0.56  0.9  0.46  1.0
  Na  Na6  1  0.73  0.3  0.72  1.0
  Na  Na7  1  0.92  0.9  0.81  1.0
  Na  Na8  1  0.66  0.3  0.03  1.0
  Na  Na9  1  0.27  0.9  0.94  1.0
  Na  Na10  1  0.02  0.3  0.24  1.0
  Na  Na11  1  0.63  0.9  0.15  1.0
  Ge  Ge0  1  0.12  0.3  0.32  1.0
  Ge  Ge1  1  0.52  0.9  0.23  1.0
  Ge  Ge2  1  0.77  0.3  0.95  1.0
  Ge  Ge3  1  0.16  0.9  0.86  1.0

data_Na2Ge
_symmetry_space_group_name_H-M   P-1
_cell_length_a   5.21
_cell_length_b   5.29
_cell_length_c   10.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Na2Ge
_chemical_formula_sum   'Na8 Ge4'
_cell_volume   280.27
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  Na0  2  0.3  0.27  0.22  1.0
  Na  Na1  2  0.3  0.63  0.35  1.0
  Na  Na2  2  0.3  0.92  0.87  1.0
  Na  Na3  2  0.3  0.98  0.56  1.0
  Ge  Ge4  2  0.3  0.52  0.27  1.0
  Ge  Ge5  2  0.3  0.88  0.64  1.0

Na Na Na Na Na Na Na Na Ge Ge Ge Ge
Na Na Na Na Na Na Na Na Ge Ge Ge Ge 0 8 o o o 0 1 o - o 1 9 o o o 2 3 o - o 2 10 o o o 3 11 + o o 4 10 o o - 5 11 o o o 6 8 o o o 7 9 o o o 
Na2Ge crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four Na2Ge clusters. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted single-bond geometry to one Ge(1) atom. The Na(1)-Ge(1) bond length is 1.38 Å. In the second Na site, Na(4) is bonded in a single-bond geometry to one Ge(1) atom. The Na(4)-Ge(1) bond length is 1.06 Å. Ge(1) is bonded in a bent 150 degrees geometry to one Na(1) and one Na(4) atom.