The crystal structure 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(2), one O(3), one O(5), and three equivalent O(1) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ge(2)O4 tetrahedra, and edges with two equivalent Na(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. In the second Na site, Na(2) is bonded to one O(1), one O(4), and three equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with three equivalent Ge(1)O4 tetrahedra, corners with two equivalent Na(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O6 octahedra,  an edgeedge with one Ge(1)O4 tetrahedra, and edges with two equivalent Na(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 25-68°. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(5), and two equivalent O(4) atoms to form GeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with three equivalent Na(2)O5 trigonal bipyramids, and  an edgeedge with one Na(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 39-54°. In the second Ge site, Ge(2) is bonded to one O(1), one O(5), and two equivalent O(3) atoms to form GeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra,  a cornercorner with one Na(2)O5 trigonal bipyramid, and edges with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-68°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), three equivalent Na(1), and one Ge(2) atom to form a mixture of distorted edge and corner-sharing ONa4Ge trigonal bipyramids. In the second O site, O(2) is bonded to one Na(1), three equivalent Na(2), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing ONa4Ge trigonal bipyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1) and two equivalent Ge(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2) and two equivalent Ge(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Na(1), 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   4.921
_cell_length_b   8.385
_cell_length_c   12.549
_cell_angle_alpha   77.067
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   504.716
_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  0.716  0.140  0.026  1.0
  Na  Na1  1  0.256  0.380  0.051  1.0
  Na  Na2  1  0.756  0.620  0.449  1.0
  Na  Na3  1  0.784  0.140  0.526  1.0
  Na  Na4  1  0.216  0.860  0.474  1.0
  Na  Na5  1  0.244  0.380  0.551  1.0
  Na  Na6  1  0.744  0.620  0.949  1.0
  Na  Na7  1  0.284  0.860  0.974  1.0
  Ge  Ge8  1  0.803  0.400  0.223  1.0
  Ge  Ge9  1  0.669  0.024  0.323  1.0
  Ge  Ge10  1  0.169  0.976  0.177  1.0
  Ge  Ge11  1  0.303  0.600  0.277  1.0
  Ge  Ge12  1  0.697  0.400  0.723  1.0
  Ge  Ge13  1  0.831  0.024  0.823  1.0
  Ge  Ge14  1  0.331  0.976  0.677  1.0
  Ge  Ge15  1  0.197  0.600  0.777  1.0
  O  O16  1  0.242  0.104  0.055  1.0
  O  O17  1  0.729  0.387  0.092  1.0
  O  O18  1  0.314  0.014  0.298  1.0
  O  O19  1  0.160  0.437  0.227  1.0
  O  O20  1  0.241  0.772  0.168  1.0
  O  O21  1  0.741  0.228  0.332  1.0
  O  O22  1  0.660  0.563  0.273  1.0
  O  O23  1  0.814  0.986  0.202  1.0
  O  O24  1  0.229  0.613  0.408  1.0
  O  O25  1  0.258  0.104  0.555  1.0
  O  O26  1  0.742  0.896  0.445  1.0
  O  O27  1  0.771  0.387  0.592  1.0
  O  O28  1  0.186  0.014  0.798  1.0
  O  O29  1  0.340  0.437  0.727  1.0
  O  O30  1  0.259  0.772  0.668  1.0
  O  O31  1  0.759  0.228  0.832  1.0
  O  O32  1  0.840  0.563  0.773  1.0
  O  O33  1  0.686  0.986  0.702  1.0
  O  O34  1  0.271  0.613  0.908  1.0
  O  O35  1  0.758  0.896  0.945  1.0
[/CIF]
.
The crystal structure 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(2), one O(3), one O(5), and three equivalent O(1) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Na(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ge(2)O4 tetrahedra, and edges with two equivalent Na(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. In the second Na site, Na(2) is bonded to one O(1), one O(4), and three equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with three equivalent Ge(1)O4 tetrahedra, corners with two equivalent Na(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O6 octahedra,  an edgeedge with one Ge(1)O4 tetrahedra, and edges with two equivalent Na(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 25-68°. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(5), and two equivalent O(4) atoms to form GeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with three equivalent Na(2)O5 trigonal bipyramids, and  an edgeedge with one Na(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 39-54°. In the second Ge site, Ge(2) is bonded to one O(1), one O(5), and two equivalent O(3) atoms to form GeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra,  a cornercorner with one Na(2)O5 trigonal bipyramid, and edges with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-68°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), three equivalent Na(1), and one Ge(2) atom to form a mixture of distorted edge and corner-sharing ONa4Ge trigonal bipyramids. In the second O site, O(2) is bonded to one Na(1), three equivalent Na(2), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing ONa4Ge trigonal bipyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1) and two equivalent Ge(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2) and two equivalent Ge(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Na(1), 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   4.921
_cell_length_b   8.385
_cell_length_c   12.549
_cell_angle_alpha   77.067
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   504.716
_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  0.716  0.140  0.026  1.0
  Na  Na1  1  0.256  0.380  0.051  1.0
  Na  Na2  1  0.756  0.620  0.449  1.0
  Na  Na3  1  0.784  0.140  0.526  1.0
  Na  Na4  1  0.216  0.860  0.474  1.0
  Na  Na5  1  0.244  0.380  0.551  1.0
  Na  Na6  1  0.744  0.620  0.949  1.0
  Na  Na7  1  0.284  0.860  0.974  1.0
  Ge  Ge8  1  0.803  0.400  0.223  1.0
  Ge  Ge9  1  0.669  0.024  0.323  1.0
  Ge  Ge10  1  0.169  0.976  0.177  1.0
  Ge  Ge11  1  0.303  0.600  0.277  1.0
  Ge  Ge12  1  0.697  0.400  0.723  1.0
  Ge  Ge13  1  0.831  0.024  0.823  1.0
  Ge  Ge14  1  0.331  0.976  0.677  1.0
  Ge  Ge15  1  0.197  0.600  0.777  1.0
  O  O16  1  0.242  0.104  0.055  1.0
  O  O17  1  0.729  0.387  0.092  1.0
  O  O18  1  0.314  0.014  0.298  1.0
  O  O19  1  0.160  0.437  0.227  1.0
  O  O20  1  0.241  0.772  0.168  1.0
  O  O21  1  0.741  0.228  0.332  1.0
  O  O22  1  0.660  0.563  0.273  1.0
  O  O23  1  0.814  0.986  0.202  1.0
  O  O24  1  0.229  0.613  0.408  1.0
  O  O25  1  0.258  0.104  0.555  1.0
  O  O26  1  0.742  0.896  0.445  1.0
  O  O27  1  0.771  0.387  0.592  1.0
  O  O28  1  0.186  0.014  0.798  1.0
  O  O29  1  0.340  0.437  0.727  1.0
  O  O30  1  0.259  0.772  0.668  1.0
  O  O31  1  0.759  0.228  0.832  1.0
  O  O32  1  0.840  0.563  0.773  1.0
  O  O33  1  0.686  0.986  0.702  1.0
  O  O34  1  0.271  0.613  0.908  1.0
  O  O35  1  0.758  0.896  0.945  1.0
[/CIF]
.