data_Na2GeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.28
_cell_length_b   6.28
_cell_length_c   6.28
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2GeO4
_chemical_formula_sum   'Na4 Ge2 O8'
_cell_volume   175.41
_cell_formula_units_Z   2
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  0.33  0.33  0.55  1.0
  Na  Na3  1  0.55  0.55  0.55  1.0
  Na  Na4  1  0.55  0.33  0.33  1.0
  Na  Na5  1  0.33  0.55  0.33  1.0
  Ge  Ge0  1  0.0  0.0  0.0  1.0
  Ge  Ge1  1  0.22  0.22  0.22  1.0
  O  O6  1  0.46  0.46  0.87  1.0
  O  O7  1  0.24  0.65  0.65  1.0
  O  O8  1  0.24  0.24  0.24  1.0
  O  O9  1  0.65  0.24  0.65  1.0
  O  O10  1  0.46  0.87  0.46  1.0
  O  O11  1  0.87  0.87  0.87  1.0
  O  O12  1  0.87  0.46  0.46  1.0
  O  O13  1  0.65  0.65  0.24  1.0

data_Na2GeO4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.28
_cell_length_b   6.28
_cell_length_c   15.39
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na2GeO4
_chemical_formula_sum   'Na12 Ge6 O24'
_cell_volume   526.23
_cell_formula_units_Z   6
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  9  0.07  0.15  0.59  1.0
  Na  Na1  3  0.0  0.0  0.45  1.0
  Ge  Ge2  3  0.0  0.0  0.0  1.0
  Ge  Ge3  3  0.0  0.0  0.78  1.0
  O  O4  9  0.06  0.53  0.07  1.0
  O  O5  9  0.2  0.4  0.16  1.0
  O  O6  3  0.0  0.0  0.13  1.0
  O  O7  3  0.0  0.0  0.76  1.0

Na Na Na Na Ge Ge O O O O O O O O
Na Na Na Na Ge Ge O O O O O O O O 0 3 o o o 0 2 o o o 0 7 o o o 0 9 o o o 1 9 o o o 1 6 o o o 1 7 o o o 1 12 o o o 1 13 o o o 1 10 o o o 2 3 o o o 2 9 o o o 2 13 o o o 3 7 o o o 3 13 o o o 4 11 - - - 5 8 o o o 6 7 o o o 6 9 o o o 7 10 o o o 7 11 - o o 9 12 o o o 9 11 o - o 10 13 o o o 11 13 o o + 12 13 o o o 
Na2GeO4 crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent Na(1), one Ge(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted NaNa2GeO5 hexagonal bipyramids that share corners with two equivalent Na(1)Na2GeO5 hexagonal bipyramids, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra, and faces with two equivalent Na(1)Na2GeO5 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 30°. Both Na(1)-Na(1) bond lengths are 1.39 Å. The Na(1)-Ge(1) bond length is 3.04 Å. The Na(1)-O(3) bond length is 2.67 Å. Both Na(1)-O(1) bond lengths are 2.89 Å. Both Na(1)-O(2) bond lengths are 2.05 Å. In the second Na site, Na(2) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing NaO6 octahedra. All Na(2)-O(1) bond lengths are 1.61 Å. All Na(2)-O(2) bond lengths are 1.61 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a distorted single-bond geometry to three equivalent Na(1) and one O(4) atom. The Ge(1)-O(4) bond length is 2.05 Å. In the second Ge site, Ge(2) is bonded in a single-bond geometry to one O(3) atom. The Ge(2)-O(3) bond length is 0.30 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Na(2) and two equivalent Na(1) atoms. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Na(2) and two equivalent Na(1) atoms. In the third O site, O(3) is bonded in a single-bond geometry to three equivalent Na(1) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Ge(1) atom.