The compound described by Na2Ge2O5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids,  an edgeedge with one Ge(1)O4 tetrahedra, edges with two equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(2)O5 trigonal bipyramids. In the second Na site, Na(2) is bonded to one O(2), one O(4), and three equivalent O(3) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids,  an edgeedge with one Ge(2)O4 tetrahedra, edges with two equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(2)O5 trigonal bipyramids. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form GeO4 tetrahedra that share corners with three equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids, and  an edgeedge with one Na(1)O5 trigonal bipyramid. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form GeO4 tetrahedra that share corners with three equivalent Ge(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids, and  an edgeedge with one Na(2)O5 trigonal bipyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one Ge(1), and one Ge(2) atom. In the second O site, O(2) is bonded to one Na(2), three equivalent Na(1), and one Ge(1) atom to form a mixture of distorted corner and edge-sharing ONa4Ge trigonal bipyramids. In the third O site, O(3) is bonded to one Na(1), three equivalent Na(2), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONa4Ge trigonal bipyramids. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2), one Ge(1), and one Ge(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ge(1) and one Ge(2) atom. is represented by the CIF file [CIF]
data_Na2Ge2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.463
_cell_length_b   5.041
_cell_length_c   10.103
_cell_angle_alpha   60.588
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   552.964
_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  Na0  1  0.537  0.106  0.620  1.0
  Na  Na1  1  0.998  0.608  0.630  1.0
  Na  Na2  1  0.498  0.392  0.870  1.0
  Na  Na3  1  0.037  0.894  0.880  1.0
  Na  Na4  1  0.963  0.106  0.120  1.0
  Na  Na5  1  0.502  0.608  0.130  1.0
  Na  Na6  1  0.002  0.392  0.370  1.0
  Na  Na7  1  0.463  0.894  0.380  1.0
  Ge  Ge8  1  0.695  0.641  0.553  1.0
  Ge  Ge9  1  0.824  0.021  0.675  1.0
  Ge  Ge10  1  0.324  0.979  0.825  1.0
  Ge  Ge11  1  0.195  0.359  0.947  1.0
  Ge  Ge12  1  0.805  0.641  0.053  1.0
  Ge  Ge13  1  0.676  0.021  0.175  1.0
  Ge  Ge14  1  0.176  0.979  0.325  1.0
  Ge  Ge15  1  0.305  0.359  0.447  1.0
  O  O16  1  0.720  0.279  0.563  1.0
  O  O17  1  0.566  0.641  0.615  1.0
  O  O18  1  0.956  0.131  0.634  1.0
  O  O19  1  0.806  0.693  0.650  1.0
  O  O20  1  0.283  0.071  0.639  1.0
  O  O21  1  0.306  0.307  0.850  1.0
  O  O22  1  0.783  0.929  0.861  1.0
  O  O23  1  0.456  0.869  0.866  1.0
  O  O24  1  0.066  0.359  0.885  1.0
  O  O25  1  0.220  0.721  0.937  1.0
  O  O26  1  0.780  0.279  0.063  1.0
  O  O27  1  0.934  0.641  0.115  1.0
  O  O28  1  0.544  0.131  0.134  1.0
  O  O29  1  0.217  0.071  0.139  1.0
  O  O30  1  0.694  0.693  0.150  1.0
  O  O31  1  0.717  0.929  0.361  1.0
  O  O32  1  0.194  0.307  0.350  1.0
  O  O33  1  0.044  0.869  0.366  1.0
  O  O34  1  0.434  0.359  0.385  1.0
  O  O35  1  0.280  0.721  0.437  1.0
[/CIF]
.
The compound described by Na2Ge2O5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids,  an edgeedge with one Ge(1)O4 tetrahedra, edges with two equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(2)O5 trigonal bipyramids. In the second Na site, Na(2) is bonded to one O(2), one O(4), and three equivalent O(3) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids,  an edgeedge with one Ge(2)O4 tetrahedra, edges with two equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(2)O5 trigonal bipyramids. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form GeO4 tetrahedra that share corners with three equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids, and  an edgeedge with one Na(1)O5 trigonal bipyramid. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form GeO4 tetrahedra that share corners with three equivalent Ge(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, corners with two equivalent Na(2)O5 trigonal bipyramids, and  an edgeedge with one Na(2)O5 trigonal bipyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one Ge(1), and one Ge(2) atom. In the second O site, O(2) is bonded to one Na(2), three equivalent Na(1), and one Ge(1) atom to form a mixture of distorted corner and edge-sharing ONa4Ge trigonal bipyramids. In the third O site, O(3) is bonded to one Na(1), three equivalent Na(2), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONa4Ge trigonal bipyramids. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2), one Ge(1), and one Ge(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ge(1) and one Ge(2) atom. is represented by the CIF file [CIF]
data_Na2Ge2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.463
_cell_length_b   5.041
_cell_length_c   10.103
_cell_angle_alpha   60.588
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   552.964
_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  Na0  1  0.537  0.106  0.620  1.0
  Na  Na1  1  0.998  0.608  0.630  1.0
  Na  Na2  1  0.498  0.392  0.870  1.0
  Na  Na3  1  0.037  0.894  0.880  1.0
  Na  Na4  1  0.963  0.106  0.120  1.0
  Na  Na5  1  0.502  0.608  0.130  1.0
  Na  Na6  1  0.002  0.392  0.370  1.0
  Na  Na7  1  0.463  0.894  0.380  1.0
  Ge  Ge8  1  0.695  0.641  0.553  1.0
  Ge  Ge9  1  0.824  0.021  0.675  1.0
  Ge  Ge10  1  0.324  0.979  0.825  1.0
  Ge  Ge11  1  0.195  0.359  0.947  1.0
  Ge  Ge12  1  0.805  0.641  0.053  1.0
  Ge  Ge13  1  0.676  0.021  0.175  1.0
  Ge  Ge14  1  0.176  0.979  0.325  1.0
  Ge  Ge15  1  0.305  0.359  0.447  1.0
  O  O16  1  0.720  0.279  0.563  1.0
  O  O17  1  0.566  0.641  0.615  1.0
  O  O18  1  0.956  0.131  0.634  1.0
  O  O19  1  0.806  0.693  0.650  1.0
  O  O20  1  0.283  0.071  0.639  1.0
  O  O21  1  0.306  0.307  0.850  1.0
  O  O22  1  0.783  0.929  0.861  1.0
  O  O23  1  0.456  0.869  0.866  1.0
  O  O24  1  0.066  0.359  0.885  1.0
  O  O25  1  0.220  0.721  0.937  1.0
  O  O26  1  0.780  0.279  0.063  1.0
  O  O27  1  0.934  0.641  0.115  1.0
  O  O28  1  0.544  0.131  0.134  1.0
  O  O29  1  0.217  0.071  0.139  1.0
  O  O30  1  0.694  0.693  0.150  1.0
  O  O31  1  0.717  0.929  0.361  1.0
  O  O32  1  0.194  0.307  0.350  1.0
  O  O33  1  0.044  0.869  0.366  1.0
  O  O34  1  0.434  0.359  0.385  1.0
  O  O35  1  0.280  0.721  0.437  1.0
[/CIF]
.