The material described by Sn2Ge2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted pentagonal planar geometry to one O(2), one O(4), one O(5), one O(7), and one O(9) atom. In the second Sn site, Sn(2) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(6) atom to form distorted SnO6 octahedra that share  a cornercorner with one Ge(3)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, and corners with three equivalent Ge(1)O4 tetrahedra. In the third Sn site, Sn(3) is bonded to one O(11), one O(12), one O(13), one O(5), one O(8), and one O(9) atom to form SnO6 octahedra that share  a cornercorner with one Ge(1)O4 tetrahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with two equivalent Ge(3)O4 tetrahedra, and corners with three equivalent Ge(4)O4 tetrahedra. In the fourth Sn site, Sn(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(6), and one O(7) atom. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Sn(3)O6 octahedra and corners with three equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-52°. In the second Ge site, Ge(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form GeO4 tetrahedra that share  a cornercorner with one Sn(3)O6 octahedra, corners with two equivalent Sn(2)O6 octahedra, and  a cornercorner with one Ge(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-62°. In the third Ge site, Ge(3) is bonded to one O(10), one O(12), one O(14), and one O(9) atom to form GeO4 tetrahedra that share  a cornercorner with one Sn(2)O6 octahedra, corners with two equivalent Sn(3)O6 octahedra, and  a cornercorner with one Ge(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-54°. In the fourth Ge site, Ge(4) is bonded to one O(11), one O(13), one O(14), and one O(8) atom to form GeO4 tetrahedra that share corners with three equivalent Sn(3)O6 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, and  a cornercorner with one Ge(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-54°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one Ge(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(2), and one Ge(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(2), and one Ge(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(3), and one Ge(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Sn(2), one Sn(4), and one Ge(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(4), and one Ge(2) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Sn(3), one Ge(2), and one Ge(4) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(3), and one Ge(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Sn(2), one Sn(4), and one Ge(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Sn(3), one Sn(4), and one Ge(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Sn(3), one Sn(4), and one Ge(3) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Sn(3), one Sn(4), and one Ge(4) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Ge(3) and one Ge(4) atom. is represented by the CIF file [CIF]
data_Sn2Ge2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.908
_cell_length_b   6.978
_cell_length_c   13.264
_cell_angle_alpha   80.916
_cell_angle_beta   84.633
_cell_angle_gamma   81.530
_symmetry_Int_Tables_number   1
_cell_volume   622.851
_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
  Sn  Sn0  1  0.418  0.225  0.132  1.0
  Sn  Sn1  1  0.063  0.669  0.137  1.0
  Sn  Sn2  1  0.656  0.229  0.360  1.0
  Sn  Sn3  1  0.132  0.894  0.346  1.0
  Sn  Sn4  1  0.868  0.106  0.654  1.0
  Sn  Sn5  1  0.344  0.771  0.640  1.0
  Sn  Sn6  1  0.937  0.331  0.863  1.0
  Sn  Sn7  1  0.582  0.775  0.868  1.0
  Ge  Ge8  1  0.923  0.194  0.127  1.0
  Ge  Ge9  1  0.550  0.683  0.196  1.0
  Ge  Ge10  1  0.139  0.377  0.371  1.0
  Ge  Ge11  1  0.640  0.720  0.423  1.0
  Ge  Ge12  1  0.360  0.280  0.577  1.0
  Ge  Ge13  1  0.861  0.623  0.629  1.0
  Ge  Ge14  1  0.450  0.317  0.804  1.0
  Ge  Ge15  1  0.077  0.806  0.873  1.0
  O  O16  1  0.150  0.796  0.996  1.0
  O  O17  1  0.087  0.362  0.138  1.0
  O  O18  1  0.767  0.694  0.117  1.0
  O  O19  1  0.378  0.564  0.144  1.0
  O  O20  1  0.700  0.257  0.202  1.0
  O  O21  1  0.033  0.957  0.182  1.0
  O  O22  1  0.425  0.899  0.236  1.0
  O  O23  1  0.614  0.556  0.330  1.0
  O  O24  1  0.361  0.245  0.319  1.0
  O  O25  1  0.066  0.609  0.298  1.0
  O  O26  1  0.745  0.930  0.371  1.0
  O  O27  1  0.956  0.224  0.372  1.0
  O  O28  1  0.409  0.769  0.489  1.0
  O  O29  1  0.191  0.425  0.493  1.0
  O  O30  1  0.809  0.575  0.507  1.0
  O  O31  1  0.591  0.231  0.511  1.0
  O  O32  1  0.044  0.776  0.628  1.0
  O  O33  1  0.255  0.070  0.629  1.0
  O  O34  1  0.934  0.391  0.702  1.0
  O  O35  1  0.639  0.755  0.681  1.0
  O  O36  1  0.386  0.444  0.670  1.0
  O  O37  1  0.575  0.101  0.764  1.0
  O  O38  1  0.967  0.043  0.818  1.0
  O  O39  1  0.300  0.743  0.798  1.0
  O  O40  1  0.622  0.436  0.856  1.0
  O  O41  1  0.233  0.306  0.883  1.0
  O  O42  1  0.913  0.638  0.862  1.0
  O  O43  1  0.850  0.204  0.004  1.0
[/CIF]
.
The material described by Sn2Ge2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted pentagonal planar geometry to one O(2), one O(4), one O(5), one O(7), and one O(9) atom. In the second Sn site, Sn(2) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(6) atom to form distorted SnO6 octahedra that share  a cornercorner with one Ge(3)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, and corners with three equivalent Ge(1)O4 tetrahedra. In the third Sn site, Sn(3) is bonded to one O(11), one O(12), one O(13), one O(5), one O(8), and one O(9) atom to form SnO6 octahedra that share  a cornercorner with one Ge(1)O4 tetrahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with two equivalent Ge(3)O4 tetrahedra, and corners with three equivalent Ge(4)O4 tetrahedra. In the fourth Sn site, Sn(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(6), and one O(7) atom. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Sn(3)O6 octahedra and corners with three equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-52°. In the second Ge site, Ge(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form GeO4 tetrahedra that share  a cornercorner with one Sn(3)O6 octahedra, corners with two equivalent Sn(2)O6 octahedra, and  a cornercorner with one Ge(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-62°. In the third Ge site, Ge(3) is bonded to one O(10), one O(12), one O(14), and one O(9) atom to form GeO4 tetrahedra that share  a cornercorner with one Sn(2)O6 octahedra, corners with two equivalent Sn(3)O6 octahedra, and  a cornercorner with one Ge(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-54°. In the fourth Ge site, Ge(4) is bonded to one O(11), one O(13), one O(14), and one O(8) atom to form GeO4 tetrahedra that share corners with three equivalent Sn(3)O6 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, and  a cornercorner with one Ge(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-54°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one Ge(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(2), and one Ge(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(2), and one Ge(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(3), and one Ge(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Sn(2), one Sn(4), and one Ge(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Sn(1), one Sn(4), and one Ge(2) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Sn(3), one Ge(2), and one Ge(4) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(3), and one Ge(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Sn(2), one Sn(4), and one Ge(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Sn(3), one Sn(4), and one Ge(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Sn(3), one Sn(4), and one Ge(3) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Sn(3), one Sn(4), and one Ge(4) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Ge(3) and one Ge(4) atom. is represented by the CIF file [CIF]
data_Sn2Ge2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.908
_cell_length_b   6.978
_cell_length_c   13.264
_cell_angle_alpha   80.916
_cell_angle_beta   84.633
_cell_angle_gamma   81.530
_symmetry_Int_Tables_number   1
_cell_volume   622.851
_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
  Sn  Sn0  1  0.418  0.225  0.132  1.0
  Sn  Sn1  1  0.063  0.669  0.137  1.0
  Sn  Sn2  1  0.656  0.229  0.360  1.0
  Sn  Sn3  1  0.132  0.894  0.346  1.0
  Sn  Sn4  1  0.868  0.106  0.654  1.0
  Sn  Sn5  1  0.344  0.771  0.640  1.0
  Sn  Sn6  1  0.937  0.331  0.863  1.0
  Sn  Sn7  1  0.582  0.775  0.868  1.0
  Ge  Ge8  1  0.923  0.194  0.127  1.0
  Ge  Ge9  1  0.550  0.683  0.196  1.0
  Ge  Ge10  1  0.139  0.377  0.371  1.0
  Ge  Ge11  1  0.640  0.720  0.423  1.0
  Ge  Ge12  1  0.360  0.280  0.577  1.0
  Ge  Ge13  1  0.861  0.623  0.629  1.0
  Ge  Ge14  1  0.450  0.317  0.804  1.0
  Ge  Ge15  1  0.077  0.806  0.873  1.0
  O  O16  1  0.150  0.796  0.996  1.0
  O  O17  1  0.087  0.362  0.138  1.0
  O  O18  1  0.767  0.694  0.117  1.0
  O  O19  1  0.378  0.564  0.144  1.0
  O  O20  1  0.700  0.257  0.202  1.0
  O  O21  1  0.033  0.957  0.182  1.0
  O  O22  1  0.425  0.899  0.236  1.0
  O  O23  1  0.614  0.556  0.330  1.0
  O  O24  1  0.361  0.245  0.319  1.0
  O  O25  1  0.066  0.609  0.298  1.0
  O  O26  1  0.745  0.930  0.371  1.0
  O  O27  1  0.956  0.224  0.372  1.0
  O  O28  1  0.409  0.769  0.489  1.0
  O  O29  1  0.191  0.425  0.493  1.0
  O  O30  1  0.809  0.575  0.507  1.0
  O  O31  1  0.591  0.231  0.511  1.0
  O  O32  1  0.044  0.776  0.628  1.0
  O  O33  1  0.255  0.070  0.629  1.0
  O  O34  1  0.934  0.391  0.702  1.0
  O  O35  1  0.639  0.755  0.681  1.0
  O  O36  1  0.386  0.444  0.670  1.0
  O  O37  1  0.575  0.101  0.764  1.0
  O  O38  1  0.967  0.043  0.818  1.0
  O  O39  1  0.300  0.743  0.798  1.0
  O  O40  1  0.622  0.436  0.856  1.0
  O  O41  1  0.233  0.306  0.883  1.0
  O  O42  1  0.913  0.638  0.862  1.0
  O  O43  1  0.850  0.204  0.004  1.0
[/CIF]
.