The compound described by Li2Si3O7 crystallizes in the orthorhombic Pbcm space group. Li(1) is bonded to one O(2) and three equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with five equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with five equivalent Li(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Li(1) and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi3Si trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_Li2Si3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.923
_cell_length_b   6.055
_cell_length_c   19.964
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   595.156
_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
  Li  Li0  1  0.442  0.354  0.044  1.0
  Li  Li1  1  0.558  0.646  0.956  1.0
  Li  Li2  1  0.058  0.354  0.956  1.0
  Li  Li3  1  0.058  0.354  0.544  1.0
  Li  Li4  1  0.942  0.646  0.044  1.0
  Li  Li5  1  0.442  0.354  0.456  1.0
  Li  Li6  1  0.942  0.646  0.456  1.0
  Li  Li7  1  0.558  0.646  0.544  1.0
  Si  Si8  1  0.553  0.147  0.605  1.0
  Si  Si9  1  0.579  0.350  0.750  1.0
  Si  Si10  1  0.053  0.853  0.605  1.0
  Si  Si11  1  0.921  0.350  0.250  1.0
  Si  Si12  1  0.421  0.650  0.250  1.0
  Si  Si13  1  0.447  0.853  0.105  1.0
  Si  Si14  1  0.053  0.853  0.895  1.0
  Si  Si15  1  0.947  0.147  0.395  1.0
  Si  Si16  1  0.947  0.147  0.105  1.0
  Si  Si17  1  0.553  0.147  0.895  1.0
  Si  Si18  1  0.079  0.650  0.750  1.0
  Si  Si19  1  0.447  0.853  0.395  1.0
  O  O20  1  0.456  0.338  0.945  1.0
  O  O21  1  0.880  0.088  0.908  1.0
  O  O22  1  0.488  0.797  0.316  1.0
  O  O23  1  0.544  0.662  0.055  1.0
  O  O24  1  0.603  0.424  0.250  1.0
  O  O25  1  0.620  0.088  0.408  1.0
  O  O26  1  0.397  0.576  0.750  1.0
  O  O27  1  0.512  0.203  0.816  1.0
  O  O28  1  0.044  0.338  0.445  1.0
  O  O29  1  0.897  0.424  0.750  1.0
  O  O30  1  0.956  0.662  0.945  1.0
  O  O31  1  0.012  0.797  0.816  1.0
  O  O32  1  0.120  0.912  0.408  1.0
  O  O33  1  0.012  0.797  0.684  1.0
  O  O34  1  0.956  0.662  0.555  1.0
  O  O35  1  0.544  0.662  0.445  1.0
  O  O36  1  0.512  0.203  0.684  1.0
  O  O37  1  0.120  0.912  0.092  1.0
  O  O38  1  0.620  0.088  0.092  1.0
  O  O39  1  0.103  0.576  0.250  1.0
  O  O40  1  0.988  0.203  0.316  1.0
  O  O41  1  0.880  0.088  0.592  1.0
  O  O42  1  0.988  0.203  0.184  1.0
  O  O43  1  0.456  0.338  0.555  1.0
  O  O44  1  0.488  0.797  0.184  1.0
  O  O45  1  0.044  0.338  0.055  1.0
  O  O46  1  0.380  0.912  0.908  1.0
  O  O47  1  0.380  0.912  0.592  1.0
[/CIF]
.
The compound described by Li2Si3O7 crystallizes in the orthorhombic Pbcm space group. Li(1) is bonded to one O(2) and three equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with five equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with five equivalent Li(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Li(1) and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi3Si trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_Li2Si3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.923
_cell_length_b   6.055
_cell_length_c   19.964
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   595.156
_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
  Li  Li0  1  0.442  0.354  0.044  1.0
  Li  Li1  1  0.558  0.646  0.956  1.0
  Li  Li2  1  0.058  0.354  0.956  1.0
  Li  Li3  1  0.058  0.354  0.544  1.0
  Li  Li4  1  0.942  0.646  0.044  1.0
  Li  Li5  1  0.442  0.354  0.456  1.0
  Li  Li6  1  0.942  0.646  0.456  1.0
  Li  Li7  1  0.558  0.646  0.544  1.0
  Si  Si8  1  0.553  0.147  0.605  1.0
  Si  Si9  1  0.579  0.350  0.750  1.0
  Si  Si10  1  0.053  0.853  0.605  1.0
  Si  Si11  1  0.921  0.350  0.250  1.0
  Si  Si12  1  0.421  0.650  0.250  1.0
  Si  Si13  1  0.447  0.853  0.105  1.0
  Si  Si14  1  0.053  0.853  0.895  1.0
  Si  Si15  1  0.947  0.147  0.395  1.0
  Si  Si16  1  0.947  0.147  0.105  1.0
  Si  Si17  1  0.553  0.147  0.895  1.0
  Si  Si18  1  0.079  0.650  0.750  1.0
  Si  Si19  1  0.447  0.853  0.395  1.0
  O  O20  1  0.456  0.338  0.945  1.0
  O  O21  1  0.880  0.088  0.908  1.0
  O  O22  1  0.488  0.797  0.316  1.0
  O  O23  1  0.544  0.662  0.055  1.0
  O  O24  1  0.603  0.424  0.250  1.0
  O  O25  1  0.620  0.088  0.408  1.0
  O  O26  1  0.397  0.576  0.750  1.0
  O  O27  1  0.512  0.203  0.816  1.0
  O  O28  1  0.044  0.338  0.445  1.0
  O  O29  1  0.897  0.424  0.750  1.0
  O  O30  1  0.956  0.662  0.945  1.0
  O  O31  1  0.012  0.797  0.816  1.0
  O  O32  1  0.120  0.912  0.408  1.0
  O  O33  1  0.012  0.797  0.684  1.0
  O  O34  1  0.956  0.662  0.555  1.0
  O  O35  1  0.544  0.662  0.445  1.0
  O  O36  1  0.512  0.203  0.684  1.0
  O  O37  1  0.120  0.912  0.092  1.0
  O  O38  1  0.620  0.088  0.092  1.0
  O  O39  1  0.103  0.576  0.250  1.0
  O  O40  1  0.988  0.203  0.316  1.0
  O  O41  1  0.880  0.088  0.592  1.0
  O  O42  1  0.988  0.203  0.184  1.0
  O  O43  1  0.456  0.338  0.555  1.0
  O  O44  1  0.488  0.797  0.184  1.0
  O  O45  1  0.044  0.338  0.055  1.0
  O  O46  1  0.380  0.912  0.908  1.0
  O  O47  1  0.380  0.912  0.592  1.0
[/CIF]
.