The material structure described by Li2FeP2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(5), one O(8), and one O(9) atom. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(10), one O(6), one O(7), and one O(9) atom. In the third Li site, Li(3) is bonded to one O(13), one O(2), one O(3), one O(5), and one O(9) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Fe(1)O5 square pyramids,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one P(1)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(10), one O(14), one O(4), and one O(6) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Fe(2)O5 square pyramids,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Fe(1)O5 square pyramid, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(14), one O(2), one O(4), one O(5), and one O(7) atom to form FeO5 square pyramids that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Li(3)O5 trigonal bipyramids, and  an edgeedge with one Li(4)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(1), one O(13), one O(3), one O(6), and one O(8) atom to form FeO5 square pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent Li(4)O5 trigonal bipyramids, and  an edgeedge with one Li(3)O5 trigonal bipyramid. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O5 square pyramid, corners with two equivalent Fe(1)O5 square pyramids,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one Li(3)O5 trigonal bipyramid, and  an edgeedge with one Li(3)O5 trigonal bipyramid. In the second P site, P(2) is bonded to one O(1), one O(12), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid, corners with two equivalent Fe(2)O5 square pyramids,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one Li(4)O5 trigonal bipyramid, and  an edgeedge with one Li(4)O5 trigonal bipyramid. In the third P site, P(3) is bonded to one O(10), one O(11), one O(14), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Li(4)O5 trigonal bipyramids. In the fourth P site, P(4) is bonded to one O(12), one O(13), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(3)O5 trigonal bipyramids. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(4), one Fe(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(3), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(4), one Fe(1), and one P(2) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(3), one Fe(1), and one P(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeP trigonal pyramids. In the sixth O site, O(6) is bonded to one Li(2), one Li(4), one Fe(2), and one P(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeP trigonal pyramids. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(4) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Li(1), one Fe(2), and one P(3) atom. In the ninth O site, O(9) is bonded to one Li(1), one Li(2), one Li(3), and one P(4) atom to form OLi3P trigonal pyramids that share  a cornercorner with one O(6)Li2FeP trigonal pyramid,  an edgeedge with one O(5)Li2FeP trigonal pyramid, and  an edgeedge with one O(10)Li3P trigonal pyramid. In the tenth O site, O(10) is bonded to one Li(1), one Li(2), one Li(4), and one P(3) atom to form OLi3P trigonal pyramids that share  a cornercorner with one O(5)Li2FeP trigonal pyramid,  an edgeedge with one O(6)Li2FeP trigonal pyramid, and  an edgeedge with one O(9)Li3P trigonal pyramid. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one P(1) and one P(3) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one P(2) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Li(4), one Fe(1), and one P(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.122
_cell_length_b   7.083
_cell_length_c   8.889
_cell_angle_alpha   112.693
_cell_angle_beta   90.926
_cell_angle_gamma   110.730
_symmetry_Int_Tables_number   1
_cell_volume   273.859
_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
  Fe  Fe0  1  0.147  0.151  0.338  1.0
  Fe  Fe1  1  0.854  0.849  0.662  1.0
  Li  Li2  1  0.097  0.336  0.015  1.0
  Li  Li3  1  0.903  0.664  0.985  1.0
  Li  Li4  1  0.310  0.649  0.758  1.0
  Li  Li5  1  0.690  0.351  0.242  1.0
  O  O6  1  0.987  0.719  0.435  1.0
  O  O7  1  0.013  0.280  0.565  1.0
  O  O8  1  0.432  0.687  0.539  1.0
  O  O9  1  0.568  0.313  0.461  1.0
  O  O10  1  0.129  0.407  0.258  1.0
  O  O11  1  0.871  0.593  0.742  1.0
  O  O12  1  0.195  0.097  0.849  1.0
  O  O13  1  0.805  0.903  0.151  1.0
  O  O14  1  0.301  0.626  0.995  1.0
  O  O15  1  0.700  0.374  0.005  1.0
  O  O16  1  0.431  0.808  0.312  1.0
  O  O17  1  0.568  0.192  0.688  1.0
  O  O18  1  0.608  0.968  0.843  1.0
  O  O19  1  0.393  0.032  0.156  1.0
  P  P20  1  0.238  0.651  0.391  1.0
  P  P21  1  0.762  0.349  0.609  1.0
  P  P22  1  0.484  0.843  0.143  1.0
  P  P23  1  0.516  0.157  0.857  1.0
[/CIF]
.
The material structure described by Li2FeP2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(5), one O(8), and one O(9) atom. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(10), one O(6), one O(7), and one O(9) atom. In the third Li site, Li(3) is bonded to one O(13), one O(2), one O(3), one O(5), and one O(9) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Fe(1)O5 square pyramids,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one P(1)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(10), one O(14), one O(4), and one O(6) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Fe(2)O5 square pyramids,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Fe(1)O5 square pyramid, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(14), one O(2), one O(4), one O(5), and one O(7) atom to form FeO5 square pyramids that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Li(3)O5 trigonal bipyramids, and  an edgeedge with one Li(4)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(1), one O(13), one O(3), one O(6), and one O(8) atom to form FeO5 square pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent Li(4)O5 trigonal bipyramids, and  an edgeedge with one Li(3)O5 trigonal bipyramid. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O5 square pyramid, corners with two equivalent Fe(1)O5 square pyramids,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one Li(3)O5 trigonal bipyramid, and  an edgeedge with one Li(3)O5 trigonal bipyramid. In the second P site, P(2) is bonded to one O(1), one O(12), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid, corners with two equivalent Fe(2)O5 square pyramids,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one Li(4)O5 trigonal bipyramid, and  an edgeedge with one Li(4)O5 trigonal bipyramid. In the third P site, P(3) is bonded to one O(10), one O(11), one O(14), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Li(4)O5 trigonal bipyramids. In the fourth P site, P(4) is bonded to one O(12), one O(13), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(3)O5 trigonal bipyramids. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(4), one Fe(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(3), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(4), one Fe(1), and one P(2) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(3), one Fe(1), and one P(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeP trigonal pyramids. In the sixth O site, O(6) is bonded to one Li(2), one Li(4), one Fe(2), and one P(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeP trigonal pyramids. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(4) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Li(1), one Fe(2), and one P(3) atom. In the ninth O site, O(9) is bonded to one Li(1), one Li(2), one Li(3), and one P(4) atom to form OLi3P trigonal pyramids that share  a cornercorner with one O(6)Li2FeP trigonal pyramid,  an edgeedge with one O(5)Li2FeP trigonal pyramid, and  an edgeedge with one O(10)Li3P trigonal pyramid. In the tenth O site, O(10) is bonded to one Li(1), one Li(2), one Li(4), and one P(3) atom to form OLi3P trigonal pyramids that share  a cornercorner with one O(5)Li2FeP trigonal pyramid,  an edgeedge with one O(6)Li2FeP trigonal pyramid, and  an edgeedge with one O(9)Li3P trigonal pyramid. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one P(1) and one P(3) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one P(2) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Li(4), one Fe(1), and one P(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.122
_cell_length_b   7.083
_cell_length_c   8.889
_cell_angle_alpha   112.693
_cell_angle_beta   90.926
_cell_angle_gamma   110.730
_symmetry_Int_Tables_number   1
_cell_volume   273.859
_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
  Fe  Fe0  1  0.147  0.151  0.338  1.0
  Fe  Fe1  1  0.854  0.849  0.662  1.0
  Li  Li2  1  0.097  0.336  0.015  1.0
  Li  Li3  1  0.903  0.664  0.985  1.0
  Li  Li4  1  0.310  0.649  0.758  1.0
  Li  Li5  1  0.690  0.351  0.242  1.0
  O  O6  1  0.987  0.719  0.435  1.0
  O  O7  1  0.013  0.280  0.565  1.0
  O  O8  1  0.432  0.687  0.539  1.0
  O  O9  1  0.568  0.313  0.461  1.0
  O  O10  1  0.129  0.407  0.258  1.0
  O  O11  1  0.871  0.593  0.742  1.0
  O  O12  1  0.195  0.097  0.849  1.0
  O  O13  1  0.805  0.903  0.151  1.0
  O  O14  1  0.301  0.626  0.995  1.0
  O  O15  1  0.700  0.374  0.005  1.0
  O  O16  1  0.431  0.808  0.312  1.0
  O  O17  1  0.568  0.192  0.688  1.0
  O  O18  1  0.608  0.968  0.843  1.0
  O  O19  1  0.393  0.032  0.156  1.0
  P  P20  1  0.238  0.651  0.391  1.0
  P  P21  1  0.762  0.349  0.609  1.0
  P  P22  1  0.484  0.843  0.143  1.0
  P  P23  1  0.516  0.157  0.857  1.0
[/CIF]
.