The structure described by LiFeP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share corners with three equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-66°. Fe(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, corners with three equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Li(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 38-53°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 22-58°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded to two equivalent Li(1), one Fe(1), and one P(2) atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. is represented by the CIF file [CIF]
data_LiFeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.064
_cell_length_b   8.455
_cell_length_c   12.245
_cell_angle_alpha   78.679
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   514.045
_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  0.726  0.122  0.295  1.0
  Li  Li1  1  0.274  0.878  0.705  1.0
  Li  Li2  1  0.774  0.622  0.795  1.0
  Li  Li3  1  0.226  0.378  0.205  1.0
  Fe  Fe4  1  0.238  0.764  0.973  1.0
  Fe  Fe5  1  0.738  0.736  0.527  1.0
  Fe  Fe6  1  0.262  0.264  0.473  1.0
  Fe  Fe7  1  0.762  0.236  0.027  1.0
  P  P8  1  0.733  0.581  0.116  1.0
  P  P9  1  0.267  0.419  0.884  1.0
  P  P10  1  0.255  0.529  0.646  1.0
  P  P11  1  0.233  0.919  0.384  1.0
  P  P12  1  0.245  0.029  0.146  1.0
  P  P13  1  0.767  0.081  0.616  1.0
  P  P14  1  0.755  0.971  0.854  1.0
  P  P15  1  0.745  0.471  0.354  1.0
  O  O16  1  0.791  0.606  0.242  1.0
  O  O17  1  0.657  0.911  0.617  1.0
  O  O18  1  0.548  0.835  0.857  1.0
  O  O19  1  0.035  0.906  0.841  1.0
  O  O20  1  0.965  0.094  0.159  1.0
  O  O21  1  0.452  0.165  0.143  1.0
  O  O22  1  0.343  0.089  0.383  1.0
  O  O23  1  0.066  0.093  0.592  1.0
  O  O24  1  0.709  0.106  0.742  1.0
  O  O25  1  0.612  0.215  0.544  1.0
  O  O26  1  0.719  0.064  0.947  1.0
  O  O27  1  0.843  0.411  0.117  1.0
  O  O28  1  0.952  0.335  0.357  1.0
  O  O29  1  0.465  0.406  0.341  1.0
  O  O30  1  0.219  0.436  0.553  1.0
  O  O31  1  0.291  0.894  0.258  1.0
  O  O32  1  0.112  0.285  0.956  1.0
  O  O33  1  0.209  0.394  0.758  1.0
  O  O34  1  0.434  0.593  0.092  1.0
  O  O35  1  0.888  0.715  0.044  1.0
  O  O36  1  0.566  0.407  0.908  1.0
  O  O37  1  0.781  0.564  0.447  1.0
  O  O38  1  0.535  0.594  0.659  1.0
  O  O39  1  0.048  0.665  0.643  1.0
  O  O40  1  0.157  0.589  0.883  1.0
  O  O41  1  0.281  0.936  0.053  1.0
  O  O42  1  0.388  0.785  0.456  1.0
  O  O43  1  0.934  0.907  0.408  1.0
[/CIF]
.
The structure described by LiFeP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share corners with three equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-66°. Fe(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, corners with three equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Li(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 38-53°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 22-58°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded to two equivalent Li(1), one Fe(1), and one P(2) atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. is represented by the CIF file [CIF]
data_LiFeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.064
_cell_length_b   8.455
_cell_length_c   12.245
_cell_angle_alpha   78.679
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   514.045
_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  0.726  0.122  0.295  1.0
  Li  Li1  1  0.274  0.878  0.705  1.0
  Li  Li2  1  0.774  0.622  0.795  1.0
  Li  Li3  1  0.226  0.378  0.205  1.0
  Fe  Fe4  1  0.238  0.764  0.973  1.0
  Fe  Fe5  1  0.738  0.736  0.527  1.0
  Fe  Fe6  1  0.262  0.264  0.473  1.0
  Fe  Fe7  1  0.762  0.236  0.027  1.0
  P  P8  1  0.733  0.581  0.116  1.0
  P  P9  1  0.267  0.419  0.884  1.0
  P  P10  1  0.255  0.529  0.646  1.0
  P  P11  1  0.233  0.919  0.384  1.0
  P  P12  1  0.245  0.029  0.146  1.0
  P  P13  1  0.767  0.081  0.616  1.0
  P  P14  1  0.755  0.971  0.854  1.0
  P  P15  1  0.745  0.471  0.354  1.0
  O  O16  1  0.791  0.606  0.242  1.0
  O  O17  1  0.657  0.911  0.617  1.0
  O  O18  1  0.548  0.835  0.857  1.0
  O  O19  1  0.035  0.906  0.841  1.0
  O  O20  1  0.965  0.094  0.159  1.0
  O  O21  1  0.452  0.165  0.143  1.0
  O  O22  1  0.343  0.089  0.383  1.0
  O  O23  1  0.066  0.093  0.592  1.0
  O  O24  1  0.709  0.106  0.742  1.0
  O  O25  1  0.612  0.215  0.544  1.0
  O  O26  1  0.719  0.064  0.947  1.0
  O  O27  1  0.843  0.411  0.117  1.0
  O  O28  1  0.952  0.335  0.357  1.0
  O  O29  1  0.465  0.406  0.341  1.0
  O  O30  1  0.219  0.436  0.553  1.0
  O  O31  1  0.291  0.894  0.258  1.0
  O  O32  1  0.112  0.285  0.956  1.0
  O  O33  1  0.209  0.394  0.758  1.0
  O  O34  1  0.434  0.593  0.092  1.0
  O  O35  1  0.888  0.715  0.044  1.0
  O  O36  1  0.566  0.407  0.908  1.0
  O  O37  1  0.781  0.564  0.447  1.0
  O  O38  1  0.535  0.594  0.659  1.0
  O  O39  1  0.048  0.665  0.643  1.0
  O  O40  1  0.157  0.589  0.883  1.0
  O  O41  1  0.281  0.936  0.053  1.0
  O  O42  1  0.388  0.785  0.456  1.0
  O  O43  1  0.934  0.907  0.408  1.0
[/CIF]
.