data_Na2FeGe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   4.79
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2FeGe
_chemical_formula_sum   'Na2 Fe1 Ge1'
_cell_volume   77.62
_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  0.69  0.69  0.69  1.0
  Na  Na3  1  0.08  0.08  0.08  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Ge  Ge1  1  0.39  0.39  0.39  1.0

data_Na2FeGe
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   11.73
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na2FeGe
_chemical_formula_sum   'Na6 Fe3 Ge3'
_cell_volume   232.87
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.31  1.0
  Na  Na1  3  0.0  0.0  0.92  1.0
  Fe  Fe2  3  0.0  0.0  0.0  1.0
  Ge  Ge3  3  0.0  0.0  0.61  1.0

Na Na Fe Ge
Na Na Fe Ge 0 3 o o + 0 3 o + o 0 3 + o o 0 2 o + + 0 2 + o + 0 2 + + o 0 1 o + + 0 1 + o + 0 1 + + o 1 2 o o o 1 3 o o - 1 3 o - o 1 3 - o o 2 3 o o - 2 3 o - o 2 3 - o o 
Na2FeGe crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 11-coordinate geometry to three equivalent Na(2), four equivalent Fe(1), and four equivalent Ge(1) atoms. All Na(1)-Na(2) bond lengths are 2.83 Å. There are three shorter (2.78 Å) and one longer (3.60 Å) Na(1)-Fe(1) bond length. There are three shorter (2.78 Å) and one longer (3.60 Å) Na(1)-Ge(1) bond length. In the second Na site, Na(2) is bonded in a single-bond geometry to three equivalent Na(1), one Fe(1), and three equivalent Ge(1) atoms. The Na(2)-Fe(1) bond length is 0.92 Å. All Na(2)-Ge(1) bond lengths are 2.78 Å. Fe(1) is bonded in a single-bond geometry to one Na(2) and four equivalent Na(1) atoms. Ge(1) is bonded in a 6-coordinate geometry to three equivalent Na(2) and four equivalent Na(1) atoms.