The structure described by Li4P2O7 is Clathrate-derived structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(6), and two equivalent O(3) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the fourth Li site, Li(4) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(5), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with two equivalent Li(3)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, and corners with three equivalent Li(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the second O site, O(2) is bonded to one Li(2), one Li(3), one Li(4), and one P(2) atom to form distorted corner-sharing OLi3P trigonal pyramids. In the third O site, O(3) is bonded to one Li(3), two equivalent Li(1), and one P(2) atom to form a mixture of distorted corner and edge-sharing OLi3P trigonal pyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(3), one Li(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Li(2), one Li(4), and one P(1) atom. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Li(3), and one P(1) atom to form a mixture of corner and edge-sharing OLi3P tetrahedra. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Li(4), one P(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li4P2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.160
_cell_length_b   7.069
_cell_length_c   8.510
_cell_angle_alpha   103.019
_cell_angle_beta   89.979
_cell_angle_gamma   111.145
_symmetry_Int_Tables_number   1
_cell_volume   280.945
_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  0.254  0.145  0.012  1.0
  Li  Li1  1  0.746  0.855  0.988  1.0
  Li  Li2  1  0.606  0.587  0.246  1.0
  Li  Li3  1  0.394  0.413  0.754  1.0
  Li  Li4  1  0.974  0.325  0.209  1.0
  Li  Li5  1  0.026  0.675  0.791  1.0
  Li  Li6  1  0.947  0.245  0.550  1.0
  Li  Li7  1  0.053  0.755  0.450  1.0
  P  P8  1  0.428  0.214  0.369  1.0
  P  P9  1  0.572  0.786  0.631  1.0
  P  P10  1  0.216  0.777  0.154  1.0
  P  P11  1  0.784  0.223  0.846  1.0
  O  O12  1  0.484  0.741  0.126  1.0
  O  O13  1  0.991  0.601  0.207  1.0
  O  O14  1  0.009  0.399  0.793  1.0
  O  O15  1  0.118  0.849  0.017  1.0
  O  O16  1  0.263  0.744  0.623  1.0
  O  O17  1  0.737  0.256  0.377  1.0
  O  O18  1  0.682  0.727  0.471  1.0
  O  O19  1  0.318  0.273  0.529  1.0
  O  O20  1  0.661  0.702  0.764  1.0
  O  O21  1  0.339  0.298  0.236  1.0
  O  O22  1  0.266  0.961  0.317  1.0
  O  O23  1  0.734  0.039  0.683  1.0
  O  O24  1  0.882  0.151  0.983  1.0
  O  O25  1  0.516  0.259  0.874  1.0
[/CIF]
.
The structure described by Li4P2O7 is Clathrate-derived structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(6), and two equivalent O(3) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the fourth Li site, Li(4) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(5), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with two equivalent Li(3)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, and corners with three equivalent Li(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the second O site, O(2) is bonded to one Li(2), one Li(3), one Li(4), and one P(2) atom to form distorted corner-sharing OLi3P trigonal pyramids. In the third O site, O(3) is bonded to one Li(3), two equivalent Li(1), and one P(2) atom to form a mixture of distorted corner and edge-sharing OLi3P trigonal pyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(3), one Li(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Li(2), one Li(4), and one P(1) atom. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Li(3), and one P(1) atom to form a mixture of corner and edge-sharing OLi3P tetrahedra. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Li(4), one P(1), and one P(2) atom. is represented by the CIF file [CIF]
data_Li4P2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.160
_cell_length_b   7.069
_cell_length_c   8.510
_cell_angle_alpha   103.019
_cell_angle_beta   89.979
_cell_angle_gamma   111.145
_symmetry_Int_Tables_number   1
_cell_volume   280.945
_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  0.254  0.145  0.012  1.0
  Li  Li1  1  0.746  0.855  0.988  1.0
  Li  Li2  1  0.606  0.587  0.246  1.0
  Li  Li3  1  0.394  0.413  0.754  1.0
  Li  Li4  1  0.974  0.325  0.209  1.0
  Li  Li5  1  0.026  0.675  0.791  1.0
  Li  Li6  1  0.947  0.245  0.550  1.0
  Li  Li7  1  0.053  0.755  0.450  1.0
  P  P8  1  0.428  0.214  0.369  1.0
  P  P9  1  0.572  0.786  0.631  1.0
  P  P10  1  0.216  0.777  0.154  1.0
  P  P11  1  0.784  0.223  0.846  1.0
  O  O12  1  0.484  0.741  0.126  1.0
  O  O13  1  0.991  0.601  0.207  1.0
  O  O14  1  0.009  0.399  0.793  1.0
  O  O15  1  0.118  0.849  0.017  1.0
  O  O16  1  0.263  0.744  0.623  1.0
  O  O17  1  0.737  0.256  0.377  1.0
  O  O18  1  0.682  0.727  0.471  1.0
  O  O19  1  0.318  0.273  0.529  1.0
  O  O20  1  0.661  0.702  0.764  1.0
  O  O21  1  0.339  0.298  0.236  1.0
  O  O22  1  0.266  0.961  0.317  1.0
  O  O23  1  0.734  0.039  0.683  1.0
  O  O24  1  0.882  0.151  0.983  1.0
  O  O25  1  0.516  0.259  0.874  1.0
[/CIF]
.