The compound described by K2Ge2Se5 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to one Se(3), one Se(4), one Se(5), and two equivalent Se(1) atoms to form distorted KSe5 trigonal bipyramids that share  a cornercorner with one Ge(3)Se4 tetrahedra, corners with three equivalent Ge(1)Se4 tetrahedra, corners with two equivalent K(1)Se5 trigonal bipyramids,  an edgeedge with one Ge(2)Se4 tetrahedra, and  an edgeedge with one K(1)Se5 trigonal bipyramid. In the second K site, K(2) is bonded in a 6-coordinate geometry to one Se(5), one Se(6), two equivalent Se(1), and two equivalent Se(3) atoms. In the third K site, K(3) is bonded in a 7-coordinate geometry to one Se(4), one Se(5), one Se(6), two equivalent Se(1), and two equivalent Se(2) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(7) atom to form GeSe4 tetrahedra that share  a cornercorner with one Ge(1)Se4 tetrahedra,  a cornercorner with one Ge(2)Se4 tetrahedra,  a cornercorner with one Ge(3)Se4 tetrahedra, and corners with three equivalent K(1)Se5 trigonal bipyramids. In the second Ge site, Ge(2) is bonded to one Se(4), one Se(6), and two equivalent Se(3) atoms to form GeSe4 tetrahedra that share  a cornercorner with one Ge(3)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, and edges with two equivalent K(1)Se5 trigonal bipyramids. In the third Ge site, Ge(3) is bonded to one Se(5), one Se(6), and two equivalent Se(2) atoms to form GeSe4 tetrahedra that share  a cornercorner with one Ge(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, and corners with two equivalent K(1)Se5 trigonal bipyramids. There are seven inequivalent Se sites. In the first Se site, Se(6) is bonded in a distorted rectangular see-saw-like geometry to one K(2), one K(3), one Ge(2), and one Ge(3) atom. In the second Se site, Se(7) is bonded in a water-like geometry to two equivalent Ge(1) atoms. In the third Se site, Se(1) is bonded to one K(2), one K(3), two equivalent K(1), and one Ge(1) atom to form distorted SeK4Ge trigonal bipyramids that share corners with three equivalent Se(4)K3Ge tetrahedra, corners with two equivalent Se(5)K4Ge trigonal bipyramids,  an edgeedge with one Se(5)K4Ge trigonal bipyramid, and edges with two equivalent Se(1)K4Ge trigonal bipyramids. In the fourth Se site, Se(2) is bonded in a distorted water-like geometry to one K(3), one Ge(1), and one Ge(3) atom. In the fifth Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one K(2), one Ge(1), and one Ge(2) atom. In the sixth Se site, Se(4) is bonded to one K(3), two equivalent K(1), and one Ge(2) atom to form corner-sharing SeK3Ge tetrahedra. In the seventh Se site, Se(5) is bonded to one K(2), one K(3), two equivalent K(1), and one Ge(3) atom to form distorted SeK4Ge trigonal bipyramids that share corners with three equivalent Se(4)K3Ge tetrahedra, corners with four equivalent Se(1)K4Ge trigonal bipyramids, and edges with two equivalent Se(1)K4Ge trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Ge2Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.756
_cell_length_b   9.880
_cell_length_c   10.262
_cell_angle_alpha   89.907
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1191.920
_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
  K  K0  1  0.493  0.640  0.667  1.0
  K  K1  1  0.993  0.360  0.333  1.0
  K  K2  1  0.507  0.360  0.333  1.0
  K  K3  1  0.007  0.640  0.667  1.0
  K  K4  1  0.750  0.040  0.582  1.0
  K  K5  1  0.250  0.960  0.418  1.0
  K  K6  1  0.750  0.409  0.893  1.0
  K  K7  1  0.250  0.591  0.107  1.0
  Ge  Ge8  1  0.087  0.234  0.737  1.0
  Ge  Ge9  1  0.587  0.766  0.263  1.0
  Ge  Ge10  1  0.913  0.766  0.263  1.0
  Ge  Ge11  1  0.413  0.234  0.737  1.0
  Ge  Ge12  1  0.750  0.090  0.180  1.0
  Ge  Ge13  1  0.250  0.910  0.820  1.0
  Ge  Ge14  1  0.750  0.798  0.944  1.0
  Ge  Ge15  1  0.250  0.202  0.056  1.0
  Se  Se16  1  0.575  0.316  0.644  1.0
  Se  Se17  1  0.075  0.684  0.356  1.0
  Se  Se18  1  0.425  0.684  0.356  1.0
  Se  Se19  1  0.925  0.316  0.644  1.0
  Se  Se20  1  0.083  0.298  0.961  1.0
  Se  Se21  1  0.583  0.702  0.039  1.0
  Se  Se22  1  0.917  0.702  0.039  1.0
  Se  Se23  1  0.417  0.298  0.961  1.0
  Se  Se24  1  0.084  0.994  0.711  1.0
  Se  Se25  1  0.584  0.006  0.289  1.0
  Se  Se26  1  0.916  0.006  0.289  1.0
  Se  Se27  1  0.416  0.994  0.711  1.0
  Se  Se28  1  0.750  0.319  0.201  1.0
  Se  Se29  1  0.250  0.681  0.799  1.0
  Se  Se30  1  0.750  0.734  0.731  1.0
  Se  Se31  1  0.250  0.266  0.269  1.0
  Se  Se32  1  0.750  0.037  0.955  1.0
  Se  Se33  1  0.250  0.963  0.045  1.0
  Se  Se34  1  0.750  0.673  0.372  1.0
  Se  Se35  1  0.250  0.327  0.628  1.0
[/CIF]
.
The compound described by K2Ge2Se5 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to one Se(3), one Se(4), one Se(5), and two equivalent Se(1) atoms to form distorted KSe5 trigonal bipyramids that share  a cornercorner with one Ge(3)Se4 tetrahedra, corners with three equivalent Ge(1)Se4 tetrahedra, corners with two equivalent K(1)Se5 trigonal bipyramids,  an edgeedge with one Ge(2)Se4 tetrahedra, and  an edgeedge with one K(1)Se5 trigonal bipyramid. In the second K site, K(2) is bonded in a 6-coordinate geometry to one Se(5), one Se(6), two equivalent Se(1), and two equivalent Se(3) atoms. In the third K site, K(3) is bonded in a 7-coordinate geometry to one Se(4), one Se(5), one Se(6), two equivalent Se(1), and two equivalent Se(2) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(7) atom to form GeSe4 tetrahedra that share  a cornercorner with one Ge(1)Se4 tetrahedra,  a cornercorner with one Ge(2)Se4 tetrahedra,  a cornercorner with one Ge(3)Se4 tetrahedra, and corners with three equivalent K(1)Se5 trigonal bipyramids. In the second Ge site, Ge(2) is bonded to one Se(4), one Se(6), and two equivalent Se(3) atoms to form GeSe4 tetrahedra that share  a cornercorner with one Ge(3)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, and edges with two equivalent K(1)Se5 trigonal bipyramids. In the third Ge site, Ge(3) is bonded to one Se(5), one Se(6), and two equivalent Se(2) atoms to form GeSe4 tetrahedra that share  a cornercorner with one Ge(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, and corners with two equivalent K(1)Se5 trigonal bipyramids. There are seven inequivalent Se sites. In the first Se site, Se(6) is bonded in a distorted rectangular see-saw-like geometry to one K(2), one K(3), one Ge(2), and one Ge(3) atom. In the second Se site, Se(7) is bonded in a water-like geometry to two equivalent Ge(1) atoms. In the third Se site, Se(1) is bonded to one K(2), one K(3), two equivalent K(1), and one Ge(1) atom to form distorted SeK4Ge trigonal bipyramids that share corners with three equivalent Se(4)K3Ge tetrahedra, corners with two equivalent Se(5)K4Ge trigonal bipyramids,  an edgeedge with one Se(5)K4Ge trigonal bipyramid, and edges with two equivalent Se(1)K4Ge trigonal bipyramids. In the fourth Se site, Se(2) is bonded in a distorted water-like geometry to one K(3), one Ge(1), and one Ge(3) atom. In the fifth Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one K(2), one Ge(1), and one Ge(2) atom. In the sixth Se site, Se(4) is bonded to one K(3), two equivalent K(1), and one Ge(2) atom to form corner-sharing SeK3Ge tetrahedra. In the seventh Se site, Se(5) is bonded to one K(2), one K(3), two equivalent K(1), and one Ge(3) atom to form distorted SeK4Ge trigonal bipyramids that share corners with three equivalent Se(4)K3Ge tetrahedra, corners with four equivalent Se(1)K4Ge trigonal bipyramids, and edges with two equivalent Se(1)K4Ge trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Ge2Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.756
_cell_length_b   9.880
_cell_length_c   10.262
_cell_angle_alpha   89.907
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1191.920
_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
  K  K0  1  0.493  0.640  0.667  1.0
  K  K1  1  0.993  0.360  0.333  1.0
  K  K2  1  0.507  0.360  0.333  1.0
  K  K3  1  0.007  0.640  0.667  1.0
  K  K4  1  0.750  0.040  0.582  1.0
  K  K5  1  0.250  0.960  0.418  1.0
  K  K6  1  0.750  0.409  0.893  1.0
  K  K7  1  0.250  0.591  0.107  1.0
  Ge  Ge8  1  0.087  0.234  0.737  1.0
  Ge  Ge9  1  0.587  0.766  0.263  1.0
  Ge  Ge10  1  0.913  0.766  0.263  1.0
  Ge  Ge11  1  0.413  0.234  0.737  1.0
  Ge  Ge12  1  0.750  0.090  0.180  1.0
  Ge  Ge13  1  0.250  0.910  0.820  1.0
  Ge  Ge14  1  0.750  0.798  0.944  1.0
  Ge  Ge15  1  0.250  0.202  0.056  1.0
  Se  Se16  1  0.575  0.316  0.644  1.0
  Se  Se17  1  0.075  0.684  0.356  1.0
  Se  Se18  1  0.425  0.684  0.356  1.0
  Se  Se19  1  0.925  0.316  0.644  1.0
  Se  Se20  1  0.083  0.298  0.961  1.0
  Se  Se21  1  0.583  0.702  0.039  1.0
  Se  Se22  1  0.917  0.702  0.039  1.0
  Se  Se23  1  0.417  0.298  0.961  1.0
  Se  Se24  1  0.084  0.994  0.711  1.0
  Se  Se25  1  0.584  0.006  0.289  1.0
  Se  Se26  1  0.916  0.006  0.289  1.0
  Se  Se27  1  0.416  0.994  0.711  1.0
  Se  Se28  1  0.750  0.319  0.201  1.0
  Se  Se29  1  0.250  0.681  0.799  1.0
  Se  Se30  1  0.750  0.734  0.731  1.0
  Se  Se31  1  0.250  0.266  0.269  1.0
  Se  Se32  1  0.750  0.037  0.955  1.0
  Se  Se33  1  0.250  0.963  0.045  1.0
  Se  Se34  1  0.750  0.673  0.372  1.0
  Se  Se35  1  0.250  0.327  0.628  1.0
[/CIF]
.