The structure described by Rb2Ge2Se5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one Se(1), one Se(4), one Se(6), two equivalent Se(2), and two equivalent Se(3) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to one Se(1), one Se(2), one Se(3), one Se(5), and two equivalent Se(4) atoms. There are two 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(6) atom to form corner-sharing GeSe4 tetrahedra. In the second Ge site, Ge(2) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form corner-sharing GeSe4 tetrahedra. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted water-like geometry to one Rb(1), one Rb(2), one Ge(1), and one Ge(2) atom. In the second Se site, Se(2) is bonded to one Rb(2), two equivalent Rb(1), one Ge(1), and one Ge(2) atom to form distorted SeRb3Ge2 trigonal bipyramids that share corners with four equivalent Se(3)Rb3Ge trigonal pyramids,  an edgeedge with one Se(2)Rb3Ge2 trigonal bipyramid, and  an edgeedge with one Se(3)Rb3Ge trigonal pyramid. In the third Se site, Se(3) is bonded to one Rb(2), two equivalent Rb(1), and one Ge(1) atom to form distorted SeRb3Ge trigonal pyramids that share corners with four equivalent Se(2)Rb3Ge2 trigonal bipyramids, corners with two equivalent Se(3)Rb3Ge trigonal pyramids, and  an edgeedge with one Se(2)Rb3Ge2 trigonal bipyramid. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to one Rb(1), two equivalent Rb(2), and one Ge(2) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to two equivalent Rb(2) and two equivalent Ge(2) atoms. In the sixth Se site, Se(6) is bonded in a distorted water-like geometry to two equivalent Rb(1) and two equivalent Ge(1) atoms. is represented by the CIF file [CIF]
data_Rb2Ge2Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.562
_cell_length_b   11.562
_cell_length_c   9.469
_cell_angle_alpha   80.116
_cell_angle_beta   80.116
_cell_angle_gamma   90.009
_symmetry_Int_Tables_number   1
_cell_volume   1227.950
_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
  Rb  Rb0  1  0.789  0.525  0.118  1.0
  Rb  Rb1  1  0.475  0.211  0.382  1.0
  Rb  Rb2  1  0.211  0.475  0.882  1.0
  Rb  Rb3  1  0.525  0.789  0.618  1.0
  Rb  Rb4  1  0.052  0.212  0.386  1.0
  Rb  Rb5  1  0.788  0.948  0.114  1.0
  Rb  Rb6  1  0.948  0.788  0.614  1.0
  Rb  Rb7  1  0.212  0.052  0.886  1.0
  Ge  Ge8  1  0.733  0.471  0.598  1.0
  Ge  Ge9  1  0.529  0.267  0.902  1.0
  Ge  Ge10  1  0.267  0.529  0.402  1.0
  Ge  Ge11  1  0.471  0.733  0.098  1.0
  Ge  Ge12  1  0.133  0.730  0.112  1.0
  Ge  Ge13  1  0.270  0.867  0.388  1.0
  Ge  Ge14  1  0.867  0.270  0.888  1.0
  Ge  Ge15  1  0.730  0.133  0.612  1.0
  Se  Se16  1  0.890  0.457  0.736  1.0
  Se  Se17  1  0.543  0.110  0.764  1.0
  Se  Se18  1  0.110  0.543  0.264  1.0
  Se  Se19  1  0.457  0.890  0.236  1.0
  Se  Se20  1  0.246  0.681  0.547  1.0
  Se  Se21  1  0.319  0.754  0.953  1.0
  Se  Se22  1  0.754  0.319  0.453  1.0
  Se  Se23  1  0.681  0.246  0.047  1.0
  Se  Se24  1  0.757  0.646  0.445  1.0
  Se  Se25  1  0.354  0.243  0.055  1.0
  Se  Se26  1  0.243  0.354  0.555  1.0
  Se  Se27  1  0.646  0.757  0.945  1.0
  Se  Se28  1  0.006  0.245  0.032  1.0
  Se  Se29  1  0.755  0.994  0.468  1.0
  Se  Se30  1  0.994  0.755  0.968  1.0
  Se  Se31  1  0.245  0.006  0.532  1.0
  Se  Se32  1  0.887  0.113  0.750  1.0
  Se  Se33  1  0.113  0.887  0.250  1.0
  Se  Se34  1  0.545  0.455  0.750  1.0
  Se  Se35  1  0.455  0.545  0.250  1.0
[/CIF]
.
The structure described by Rb2Ge2Se5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one Se(1), one Se(4), one Se(6), two equivalent Se(2), and two equivalent Se(3) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to one Se(1), one Se(2), one Se(3), one Se(5), and two equivalent Se(4) atoms. There are two 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(6) atom to form corner-sharing GeSe4 tetrahedra. In the second Ge site, Ge(2) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form corner-sharing GeSe4 tetrahedra. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted water-like geometry to one Rb(1), one Rb(2), one Ge(1), and one Ge(2) atom. In the second Se site, Se(2) is bonded to one Rb(2), two equivalent Rb(1), one Ge(1), and one Ge(2) atom to form distorted SeRb3Ge2 trigonal bipyramids that share corners with four equivalent Se(3)Rb3Ge trigonal pyramids,  an edgeedge with one Se(2)Rb3Ge2 trigonal bipyramid, and  an edgeedge with one Se(3)Rb3Ge trigonal pyramid. In the third Se site, Se(3) is bonded to one Rb(2), two equivalent Rb(1), and one Ge(1) atom to form distorted SeRb3Ge trigonal pyramids that share corners with four equivalent Se(2)Rb3Ge2 trigonal bipyramids, corners with two equivalent Se(3)Rb3Ge trigonal pyramids, and  an edgeedge with one Se(2)Rb3Ge2 trigonal bipyramid. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to one Rb(1), two equivalent Rb(2), and one Ge(2) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to two equivalent Rb(2) and two equivalent Ge(2) atoms. In the sixth Se site, Se(6) is bonded in a distorted water-like geometry to two equivalent Rb(1) and two equivalent Ge(1) atoms. is represented by the CIF file [CIF]
data_Rb2Ge2Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.562
_cell_length_b   11.562
_cell_length_c   9.469
_cell_angle_alpha   80.116
_cell_angle_beta   80.116
_cell_angle_gamma   90.009
_symmetry_Int_Tables_number   1
_cell_volume   1227.950
_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
  Rb  Rb0  1  0.789  0.525  0.118  1.0
  Rb  Rb1  1  0.475  0.211  0.382  1.0
  Rb  Rb2  1  0.211  0.475  0.882  1.0
  Rb  Rb3  1  0.525  0.789  0.618  1.0
  Rb  Rb4  1  0.052  0.212  0.386  1.0
  Rb  Rb5  1  0.788  0.948  0.114  1.0
  Rb  Rb6  1  0.948  0.788  0.614  1.0
  Rb  Rb7  1  0.212  0.052  0.886  1.0
  Ge  Ge8  1  0.733  0.471  0.598  1.0
  Ge  Ge9  1  0.529  0.267  0.902  1.0
  Ge  Ge10  1  0.267  0.529  0.402  1.0
  Ge  Ge11  1  0.471  0.733  0.098  1.0
  Ge  Ge12  1  0.133  0.730  0.112  1.0
  Ge  Ge13  1  0.270  0.867  0.388  1.0
  Ge  Ge14  1  0.867  0.270  0.888  1.0
  Ge  Ge15  1  0.730  0.133  0.612  1.0
  Se  Se16  1  0.890  0.457  0.736  1.0
  Se  Se17  1  0.543  0.110  0.764  1.0
  Se  Se18  1  0.110  0.543  0.264  1.0
  Se  Se19  1  0.457  0.890  0.236  1.0
  Se  Se20  1  0.246  0.681  0.547  1.0
  Se  Se21  1  0.319  0.754  0.953  1.0
  Se  Se22  1  0.754  0.319  0.453  1.0
  Se  Se23  1  0.681  0.246  0.047  1.0
  Se  Se24  1  0.757  0.646  0.445  1.0
  Se  Se25  1  0.354  0.243  0.055  1.0
  Se  Se26  1  0.243  0.354  0.555  1.0
  Se  Se27  1  0.646  0.757  0.945  1.0
  Se  Se28  1  0.006  0.245  0.032  1.0
  Se  Se29  1  0.755  0.994  0.468  1.0
  Se  Se30  1  0.994  0.755  0.968  1.0
  Se  Se31  1  0.245  0.006  0.532  1.0
  Se  Se32  1  0.887  0.113  0.750  1.0
  Se  Se33  1  0.113  0.887  0.250  1.0
  Se  Se34  1  0.545  0.455  0.750  1.0
  Se  Se35  1  0.455  0.545  0.250  1.0
[/CIF]
.