data_Na2AlGe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.17
_cell_length_b   4.17
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2AlGe
_chemical_formula_sum   'Na2 Al1 Ge1'
_cell_volume   85.66
_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  0.09  0.0  0.46  1.0
  Na  Na3  1  0.0  0.09  0.46  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Ge  Ge1  1  0.09  0.09  0.0  1.0

data_Na2AlGe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.9
_cell_length_b   5.9
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2AlGe
_chemical_formula_sum   'Na4 Al2 Ge2'
_cell_volume   171.31
_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  0.04  0.04  0.46  1.0
  Al  Al1  2  0.0  0.0  0.0  1.0
  Ge  Ge2  2  0.09  0.0  0.0  1.0

Na Na Al Ge
(Na)2AlGe crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two disodium molecules and two AlGe clusters. In each AlGe cluster, Al(1) is bonded in a single-bond geometry to one Ge(1) atom. The Al(1)-Ge(1) bond length is 0.51 Å. Ge(1) is bonded in a single-bond geometry to one Al(1) atom.