The compound described by Li6Si2O7 crystallizes in the tetragonal P-42_1m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(2) and three equivalent O(1) atoms. In the second Li site, Li(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted LiO5 trigonal bipyramids that share corners with four equivalent Si(1)O4 tetrahedra,  an edgeedge with one Si(1)O4 tetrahedra, and  a faceface with one Li(2)O5 trigonal bipyramid. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with four equivalent Li(2)O5 trigonal bipyramids, and  an edgeedge with one Li(2)O5 trigonal bipyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Li(2), three equivalent Li(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Li(1), two equivalent Li(2), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted tetrahedral geometry to two equivalent Li(2) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Li6Si2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.769
_cell_length_b   7.769
_cell_length_c   4.906
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   296.154
_cell_formula_units_Z   2
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  0.637  0.418  0.703  1.0
  Li  Li1  1  0.363  0.582  0.703  1.0
  Li  Li2  1  0.418  0.363  0.297  1.0
  Li  Li3  1  0.582  0.637  0.297  1.0
  Li  Li4  1  0.137  0.082  0.297  1.0
  Li  Li5  1  0.082  0.863  0.703  1.0
  Li  Li6  1  0.889  0.611  0.686  1.0
  Li  Li7  1  0.389  0.889  0.314  1.0
  Li  Li8  1  0.611  0.111  0.314  1.0
  Li  Li9  1  0.111  0.389  0.686  1.0
  Li  Li10  1  0.918  0.137  0.703  1.0
  Li  Li11  1  0.863  0.918  0.297  1.0
  Si  Si12  1  0.644  0.856  0.821  1.0
  Si  Si13  1  0.144  0.644  0.179  1.0
  Si  Si14  1  0.856  0.356  0.179  1.0
  Si  Si15  1  0.356  0.144  0.821  1.0
  O  O16  1  0.164  0.097  0.709  1.0
  O  O17  1  0.903  0.164  0.291  1.0
  O  O18  1  0.597  0.664  0.709  1.0
  O  O19  1  0.403  0.336  0.709  1.0
  O  O20  1  0.336  0.597  0.291  1.0
  O  O21  1  0.664  0.403  0.291  1.0
  O  O22  1  0.631  0.869  0.154  1.0
  O  O23  1  0.131  0.631  0.846  1.0
  O  O24  1  0.869  0.369  0.846  1.0
  O  O25  1  0.369  0.131  0.154  1.0
  O  O26  1  0.500  0.000  0.683  1.0
  O  O27  1  0.000  0.500  0.317  1.0
  O  O28  1  0.836  0.903  0.709  1.0
  O  O29  1  0.097  0.836  0.291  1.0
[/CIF]
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The compound described by Li6Si2O7 crystallizes in the tetragonal P-42_1m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(2) and three equivalent O(1) atoms. In the second Li site, Li(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted LiO5 trigonal bipyramids that share corners with four equivalent Si(1)O4 tetrahedra,  an edgeedge with one Si(1)O4 tetrahedra, and  a faceface with one Li(2)O5 trigonal bipyramid. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with four equivalent Li(2)O5 trigonal bipyramids, and  an edgeedge with one Li(2)O5 trigonal bipyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Li(2), three equivalent Li(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Li(1), two equivalent Li(2), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted tetrahedral geometry to two equivalent Li(2) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Li6Si2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.769
_cell_length_b   7.769
_cell_length_c   4.906
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   296.154
_cell_formula_units_Z   2
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  0.637  0.418  0.703  1.0
  Li  Li1  1  0.363  0.582  0.703  1.0
  Li  Li2  1  0.418  0.363  0.297  1.0
  Li  Li3  1  0.582  0.637  0.297  1.0
  Li  Li4  1  0.137  0.082  0.297  1.0
  Li  Li5  1  0.082  0.863  0.703  1.0
  Li  Li6  1  0.889  0.611  0.686  1.0
  Li  Li7  1  0.389  0.889  0.314  1.0
  Li  Li8  1  0.611  0.111  0.314  1.0
  Li  Li9  1  0.111  0.389  0.686  1.0
  Li  Li10  1  0.918  0.137  0.703  1.0
  Li  Li11  1  0.863  0.918  0.297  1.0
  Si  Si12  1  0.644  0.856  0.821  1.0
  Si  Si13  1  0.144  0.644  0.179  1.0
  Si  Si14  1  0.856  0.356  0.179  1.0
  Si  Si15  1  0.356  0.144  0.821  1.0
  O  O16  1  0.164  0.097  0.709  1.0
  O  O17  1  0.903  0.164  0.291  1.0
  O  O18  1  0.597  0.664  0.709  1.0
  O  O19  1  0.403  0.336  0.709  1.0
  O  O20  1  0.336  0.597  0.291  1.0
  O  O21  1  0.664  0.403  0.291  1.0
  O  O22  1  0.631  0.869  0.154  1.0
  O  O23  1  0.131  0.631  0.846  1.0
  O  O24  1  0.869  0.369  0.846  1.0
  O  O25  1  0.369  0.131  0.154  1.0
  O  O26  1  0.500  0.000  0.683  1.0
  O  O27  1  0.000  0.500  0.317  1.0
  O  O28  1  0.836  0.903  0.709  1.0
  O  O29  1  0.097  0.836  0.291  1.0
[/CIF]
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