The material structure described by Rb4Li(Se2O7)2 crystallizes in the triclinic P1 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(5), one O(6), one O(8), and one O(9) atom. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom. In the third Rb site, Rb(3) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(6), one O(7), and one O(9) atom. In the fourth Rb site, Rb(4) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(2), one O(4), one O(5), one O(7), and one O(8) atom. Li(1) is bonded to one O(10), one O(11), one O(2), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Se(3)O4 tetrahedra and  a cornercorner with one Se(4)O4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a tetrahedral geometry to one O(1), one O(13), one O(5), and one O(9) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(2), and one O(6) atom. In the third Se site, Se(3) is bonded to one O(11), one O(14), one O(3), and one O(7) atom to form SeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra and  a cornercorner with one Se(4)O4 tetrahedra. In the fourth Se site, Se(4) is bonded to one O(12), one O(14), one O(4), and one O(8) atom to form SeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra and  a cornercorner with one Se(3)O4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(3), one Rb(4), and one Se(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Rb(3), one Rb(4), one Li(1), and one Se(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Rb(3), and one Se(3) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Rb(4), and one Se(4) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Rb(1), one Rb(2), one Rb(4), and one Se(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one Rb(3), and one Se(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), one Rb(4), and one Se(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one Rb(4), one Li(1), and one Se(4) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Rb(3), and one Se(1) atom. In the tenth O site, O(10) is bonded in a distorted L-shaped geometry to one Rb(1), one Rb(2), one Li(1), and one Se(2) atom. In the eleventh O site, O(11) is bonded in a distorted water-like geometry to one Rb(3), one Li(1), and one Se(3) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(4), and one Se(4) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Se(1) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Se(3) and one Se(4) atom. is represented by the CIF file [CIF]
data_Rb4Li(Se2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.123
_cell_length_b   7.916
_cell_length_c   8.120
_cell_angle_alpha   89.475
_cell_angle_beta   87.864
_cell_angle_gamma   59.966
_symmetry_Int_Tables_number   1
_cell_volume   451.691
_cell_formula_units_Z   1
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  0.185  0.524  0.355  1.0
  Rb  Rb1  1  0.487  0.829  0.144  1.0
  Rb  Rb2  1  0.738  0.525  0.582  1.0
  Rb  Rb3  1  0.578  0.193  0.868  1.0
  Li  Li4  1  0.087  0.315  0.831  1.0
  Se  Se5  1  0.706  0.078  0.375  1.0
  Se  Se6  1  0.926  0.295  0.114  1.0
  Se  Se7  1  0.261  0.929  0.652  1.0
  Se  Se8  1  0.092  0.698  0.881  1.0
  O  O9  1  0.621  0.249  0.523  1.0
  O  O10  1  0.820  0.375  0.927  1.0
  O  O11  1  0.325  0.789  0.486  1.0
  O  O12  1  0.264  0.639  0.010  1.0
  O  O13  1  0.548  0.154  0.226  1.0
  O  O14  1  0.840  0.486  0.245  1.0
  O  O15  1  0.434  0.864  0.781  1.0
  O  O16  1  0.148  0.516  0.748  1.0
  O  O17  1  0.748  0.862  0.448  1.0
  O  O18  1  0.158  0.227  0.062  1.0
  O  O19  1  0.142  0.168  0.622  1.0
  O  O20  1  0.874  0.797  0.958  1.0
  O  O21  1  0.920  0.040  0.296  1.0
  O  O22  1  0.068  0.905  0.758  1.0
[/CIF]
.
The material structure described by Rb4Li(Se2O7)2 crystallizes in the triclinic P1 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(5), one O(6), one O(8), and one O(9) atom. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom. In the third Rb site, Rb(3) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(6), one O(7), and one O(9) atom. In the fourth Rb site, Rb(4) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(2), one O(4), one O(5), one O(7), and one O(8) atom. Li(1) is bonded to one O(10), one O(11), one O(2), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Se(3)O4 tetrahedra and  a cornercorner with one Se(4)O4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a tetrahedral geometry to one O(1), one O(13), one O(5), and one O(9) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(2), and one O(6) atom. In the third Se site, Se(3) is bonded to one O(11), one O(14), one O(3), and one O(7) atom to form SeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra and  a cornercorner with one Se(4)O4 tetrahedra. In the fourth Se site, Se(4) is bonded to one O(12), one O(14), one O(4), and one O(8) atom to form SeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra and  a cornercorner with one Se(3)O4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(3), one Rb(4), and one Se(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Rb(3), one Rb(4), one Li(1), and one Se(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Rb(3), and one Se(3) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Rb(4), and one Se(4) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Rb(1), one Rb(2), one Rb(4), and one Se(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one Rb(3), and one Se(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), one Rb(4), and one Se(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one Rb(4), one Li(1), and one Se(4) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Rb(3), and one Se(1) atom. In the tenth O site, O(10) is bonded in a distorted L-shaped geometry to one Rb(1), one Rb(2), one Li(1), and one Se(2) atom. In the eleventh O site, O(11) is bonded in a distorted water-like geometry to one Rb(3), one Li(1), and one Se(3) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(4), and one Se(4) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Se(1) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Se(3) and one Se(4) atom. is represented by the CIF file [CIF]
data_Rb4Li(Se2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.123
_cell_length_b   7.916
_cell_length_c   8.120
_cell_angle_alpha   89.475
_cell_angle_beta   87.864
_cell_angle_gamma   59.966
_symmetry_Int_Tables_number   1
_cell_volume   451.691
_cell_formula_units_Z   1
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  0.185  0.524  0.355  1.0
  Rb  Rb1  1  0.487  0.829  0.144  1.0
  Rb  Rb2  1  0.738  0.525  0.582  1.0
  Rb  Rb3  1  0.578  0.193  0.868  1.0
  Li  Li4  1  0.087  0.315  0.831  1.0
  Se  Se5  1  0.706  0.078  0.375  1.0
  Se  Se6  1  0.926  0.295  0.114  1.0
  Se  Se7  1  0.261  0.929  0.652  1.0
  Se  Se8  1  0.092  0.698  0.881  1.0
  O  O9  1  0.621  0.249  0.523  1.0
  O  O10  1  0.820  0.375  0.927  1.0
  O  O11  1  0.325  0.789  0.486  1.0
  O  O12  1  0.264  0.639  0.010  1.0
  O  O13  1  0.548  0.154  0.226  1.0
  O  O14  1  0.840  0.486  0.245  1.0
  O  O15  1  0.434  0.864  0.781  1.0
  O  O16  1  0.148  0.516  0.748  1.0
  O  O17  1  0.748  0.862  0.448  1.0
  O  O18  1  0.158  0.227  0.062  1.0
  O  O19  1  0.142  0.168  0.622  1.0
  O  O20  1  0.874  0.797  0.958  1.0
  O  O21  1  0.920  0.040  0.296  1.0
  O  O22  1  0.068  0.905  0.758  1.0
[/CIF]
.