The compound described by Li2SeO4 crystallizes in the trigonal R-3 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with four equivalent Se(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, and  an edgeedge with one Se(1)O4 tetrahedra. Se(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Se(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Se(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to two equivalent Li(2) and one Se(1) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Li(1), one Li(2), and one Se(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2SeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.587
_cell_length_b   8.587
_cell_length_c   8.587
_cell_angle_alpha   100.853
_cell_angle_beta   100.853
_cell_angle_gamma   100.853
_symmetry_Int_Tables_number   1
_cell_volume   594.117
_cell_formula_units_Z   6
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
  Li  Li0  1  0.542  0.809  0.424  1.0
  Li  Li1  1  0.458  0.191  0.576  1.0
  Li  Li2  1  0.107  0.682  0.878  1.0
  Li  Li3  1  0.424  0.542  0.809  1.0
  Li  Li4  1  0.809  0.424  0.542  1.0
  Li  Li5  1  0.576  0.458  0.191  1.0
  Li  Li6  1  0.682  0.878  0.107  1.0
  Li  Li7  1  0.878  0.107  0.682  1.0
  Li  Li8  1  0.191  0.576  0.458  1.0
  Li  Li9  1  0.893  0.318  0.122  1.0
  Li  Li10  1  0.318  0.122  0.893  1.0
  Li  Li11  1  0.122  0.893  0.318  1.0
  Se  Se12  1  0.136  0.248  0.580  1.0
  Se  Se13  1  0.864  0.752  0.420  1.0
  Se  Se14  1  0.752  0.420  0.864  1.0
  Se  Se15  1  0.420  0.864  0.752  1.0
  Se  Se16  1  0.248  0.580  0.136  1.0
  Se  Se17  1  0.580  0.136  0.248  1.0
  O  O18  1  0.391  0.754  0.561  1.0
  O  O19  1  0.561  0.391  0.754  1.0
  O  O20  1  0.129  0.451  0.214  1.0
  O  O21  1  0.176  0.749  0.143  1.0
  O  O22  1  0.609  0.246  0.439  1.0
  O  O23  1  0.940  0.246  0.515  1.0
  O  O24  1  0.754  0.561  0.391  1.0
  O  O25  1  0.451  0.214  0.129  1.0
  O  O26  1  0.251  0.857  0.824  1.0
  O  O27  1  0.246  0.515  0.940  1.0
  O  O28  1  0.549  0.786  0.871  1.0
  O  O29  1  0.857  0.824  0.251  1.0
  O  O30  1  0.439  0.609  0.246  1.0
  O  O31  1  0.246  0.439  0.609  1.0
  O  O32  1  0.485  0.060  0.754  1.0
  O  O33  1  0.214  0.129  0.451  1.0
  O  O34  1  0.786  0.871  0.549  1.0
  O  O35  1  0.515  0.940  0.246  1.0
  O  O36  1  0.060  0.754  0.485  1.0
  O  O37  1  0.754  0.485  0.060  1.0
  O  O38  1  0.824  0.251  0.857  1.0
  O  O39  1  0.871  0.549  0.786  1.0
  O  O40  1  0.143  0.176  0.749  1.0
  O  O41  1  0.749  0.143  0.176  1.0
[/CIF]
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The compound described by Li2SeO4 crystallizes in the trigonal R-3 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with four equivalent Se(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, and  an edgeedge with one Se(1)O4 tetrahedra. Se(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Se(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Se(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to two equivalent Li(2) and one Se(1) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Li(1), one Li(2), and one Se(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2SeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.587
_cell_length_b   8.587
_cell_length_c   8.587
_cell_angle_alpha   100.853
_cell_angle_beta   100.853
_cell_angle_gamma   100.853
_symmetry_Int_Tables_number   1
_cell_volume   594.117
_cell_formula_units_Z   6
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
  Li  Li0  1  0.542  0.809  0.424  1.0
  Li  Li1  1  0.458  0.191  0.576  1.0
  Li  Li2  1  0.107  0.682  0.878  1.0
  Li  Li3  1  0.424  0.542  0.809  1.0
  Li  Li4  1  0.809  0.424  0.542  1.0
  Li  Li5  1  0.576  0.458  0.191  1.0
  Li  Li6  1  0.682  0.878  0.107  1.0
  Li  Li7  1  0.878  0.107  0.682  1.0
  Li  Li8  1  0.191  0.576  0.458  1.0
  Li  Li9  1  0.893  0.318  0.122  1.0
  Li  Li10  1  0.318  0.122  0.893  1.0
  Li  Li11  1  0.122  0.893  0.318  1.0
  Se  Se12  1  0.136  0.248  0.580  1.0
  Se  Se13  1  0.864  0.752  0.420  1.0
  Se  Se14  1  0.752  0.420  0.864  1.0
  Se  Se15  1  0.420  0.864  0.752  1.0
  Se  Se16  1  0.248  0.580  0.136  1.0
  Se  Se17  1  0.580  0.136  0.248  1.0
  O  O18  1  0.391  0.754  0.561  1.0
  O  O19  1  0.561  0.391  0.754  1.0
  O  O20  1  0.129  0.451  0.214  1.0
  O  O21  1  0.176  0.749  0.143  1.0
  O  O22  1  0.609  0.246  0.439  1.0
  O  O23  1  0.940  0.246  0.515  1.0
  O  O24  1  0.754  0.561  0.391  1.0
  O  O25  1  0.451  0.214  0.129  1.0
  O  O26  1  0.251  0.857  0.824  1.0
  O  O27  1  0.246  0.515  0.940  1.0
  O  O28  1  0.549  0.786  0.871  1.0
  O  O29  1  0.857  0.824  0.251  1.0
  O  O30  1  0.439  0.609  0.246  1.0
  O  O31  1  0.246  0.439  0.609  1.0
  O  O32  1  0.485  0.060  0.754  1.0
  O  O33  1  0.214  0.129  0.451  1.0
  O  O34  1  0.786  0.871  0.549  1.0
  O  O35  1  0.515  0.940  0.246  1.0
  O  O36  1  0.060  0.754  0.485  1.0
  O  O37  1  0.754  0.485  0.060  1.0
  O  O38  1  0.824  0.251  0.857  1.0
  O  O39  1  0.871  0.549  0.786  1.0
  O  O40  1  0.143  0.176  0.749  1.0
  O  O41  1  0.749  0.143  0.176  1.0
[/CIF]
.