The material structure described by Li2W2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Li(2)O6 octahedra, corners with two equivalent W(1)O6 octahedra, and  an edgeedge with one Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 21-82°. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), one O(7), and two equivalent O(6) atoms to form distorted LiO6 octahedra that share corners with two equivalent W(1)O6 octahedra,  a cornercorner with one Li(1)O4 trigonal pyramid,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one W(1)O6 octahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 23-27°. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(3), one O(6), one O(7), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Li(2)O6 octahedra, and  an edgeedge with one W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-27°. In the second W site, W(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Li(1), one W(1), and one W(2) atom. In the second O site, O(2) is bonded in a T-shaped geometry to one Li(1), one Li(2), and one W(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one W(1), and one W(2) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Li(1), one Li(2), and one W(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one W(2) and two equivalent W(1) atoms. In the sixth O site, O(6) is bonded to two equivalent Li(2), one W(1), and one W(2) atom to form edge-sharing OLi2W2 trigonal pyramids. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Li(1), one Li(2), and one W(1) atom. is represented by the CIF file [CIF]
data_Li2W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.262
_cell_length_b   6.933
_cell_length_c   8.706
_cell_angle_alpha   70.159
_cell_angle_beta   76.327
_cell_angle_gamma   85.046
_symmetry_Int_Tables_number   1
_cell_volume   290.274
_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  0.865  0.558  0.751  1.0
  Li  Li1  1  0.593  0.228  0.359  1.0
  Li  Li2  1  0.135  0.442  0.249  1.0
  Li  Li3  1  0.407  0.772  0.641  1.0
  W  W4  1  0.303  0.038  0.164  1.0
  W  W5  1  0.209  0.244  0.687  1.0
  W  W6  1  0.791  0.756  0.313  1.0
  W  W7  1  0.697  0.962  0.836  1.0
  O  O8  1  0.852  0.252  0.797  1.0
  O  O9  1  0.148  0.748  0.203  1.0
  O  O10  1  0.726  0.508  0.309  1.0
  O  O11  1  0.274  0.492  0.691  1.0
  O  O12  1  0.051  0.927  0.749  1.0
  O  O13  1  0.949  0.073  0.251  1.0
  O  O14  1  0.806  0.701  0.527  1.0
  O  O15  1  0.670  0.910  0.077  1.0
  O  O16  1  0.444  0.902  0.363  1.0
  O  O17  1  0.405  0.287  0.145  1.0
  O  O18  1  0.556  0.098  0.637  1.0
  O  O19  1  0.330  0.090  0.923  1.0
  O  O20  1  0.194  0.299  0.473  1.0
  O  O21  1  0.595  0.713  0.855  1.0
[/CIF]
.
The material structure described by Li2W2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Li(2)O6 octahedra, corners with two equivalent W(1)O6 octahedra, and  an edgeedge with one Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 21-82°. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), one O(7), and two equivalent O(6) atoms to form distorted LiO6 octahedra that share corners with two equivalent W(1)O6 octahedra,  a cornercorner with one Li(1)O4 trigonal pyramid,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one W(1)O6 octahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 23-27°. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(3), one O(6), one O(7), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Li(2)O6 octahedra, and  an edgeedge with one W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-27°. In the second W site, W(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Li(1), one W(1), and one W(2) atom. In the second O site, O(2) is bonded in a T-shaped geometry to one Li(1), one Li(2), and one W(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one W(1), and one W(2) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Li(1), one Li(2), and one W(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one W(2) and two equivalent W(1) atoms. In the sixth O site, O(6) is bonded to two equivalent Li(2), one W(1), and one W(2) atom to form edge-sharing OLi2W2 trigonal pyramids. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Li(1), one Li(2), and one W(1) atom. is represented by the CIF file [CIF]
data_Li2W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.262
_cell_length_b   6.933
_cell_length_c   8.706
_cell_angle_alpha   70.159
_cell_angle_beta   76.327
_cell_angle_gamma   85.046
_symmetry_Int_Tables_number   1
_cell_volume   290.274
_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  0.865  0.558  0.751  1.0
  Li  Li1  1  0.593  0.228  0.359  1.0
  Li  Li2  1  0.135  0.442  0.249  1.0
  Li  Li3  1  0.407  0.772  0.641  1.0
  W  W4  1  0.303  0.038  0.164  1.0
  W  W5  1  0.209  0.244  0.687  1.0
  W  W6  1  0.791  0.756  0.313  1.0
  W  W7  1  0.697  0.962  0.836  1.0
  O  O8  1  0.852  0.252  0.797  1.0
  O  O9  1  0.148  0.748  0.203  1.0
  O  O10  1  0.726  0.508  0.309  1.0
  O  O11  1  0.274  0.492  0.691  1.0
  O  O12  1  0.051  0.927  0.749  1.0
  O  O13  1  0.949  0.073  0.251  1.0
  O  O14  1  0.806  0.701  0.527  1.0
  O  O15  1  0.670  0.910  0.077  1.0
  O  O16  1  0.444  0.902  0.363  1.0
  O  O17  1  0.405  0.287  0.145  1.0
  O  O18  1  0.556  0.098  0.637  1.0
  O  O19  1  0.330  0.090  0.923  1.0
  O  O20  1  0.194  0.299  0.473  1.0
  O  O21  1  0.595  0.713  0.855  1.0
[/CIF]
.