The crystal structure described by LiFeP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a rectangular see-saw-like geometry to one O(4), one O(7), and two equivalent O(1) atoms. Fe(1) is bonded to one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Fe(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one P(1) and one P(2) atom. 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(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) 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 3-coordinate geometry to one Li(1), 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   6.196
_cell_length_b   7.511
_cell_length_c   12.579
_cell_angle_alpha   62.788
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   520.633
_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  0.116  0.325  0.047  1.0
  Li  Li1  1  0.616  0.675  0.453  1.0
  Li  Li2  1  0.384  0.325  0.547  1.0
  Li  Li3  1  0.884  0.675  0.953  1.0
  Fe  Fe4  1  0.377  0.207  0.268  1.0
  Fe  Fe5  1  0.123  0.207  0.768  1.0
  Fe  Fe6  1  0.877  0.793  0.232  1.0
  Fe  Fe7  1  0.623  0.793  0.732  1.0
  P  P8  1  0.112  0.689  0.716  1.0
  P  P9  1  0.649  0.223  0.040  1.0
  P  P10  1  0.149  0.777  0.460  1.0
  P  P11  1  0.612  0.311  0.784  1.0
  P  P12  1  0.388  0.689  0.216  1.0
  P  P13  1  0.851  0.223  0.540  1.0
  P  P14  1  0.351  0.777  0.960  1.0
  P  P15  1  0.888  0.311  0.284  1.0
  O  O16  1  0.790  0.402  0.011  1.0
  O  O17  1  0.683  0.191  0.296  1.0
  O  O18  1  0.033  0.758  0.581  1.0
  O  O19  1  0.066  0.246  0.224  1.0
  O  O20  1  0.293  0.966  0.409  1.0
  O  O21  1  0.641  0.538  0.721  1.0
  O  O22  1  0.440  0.206  0.113  1.0
  O  O23  1  0.141  0.462  0.779  1.0
  O  O24  1  0.533  0.242  0.919  1.0
  O  O25  1  0.940  0.794  0.387  1.0
  O  O26  1  0.793  0.034  0.091  1.0
  O  O27  1  0.710  0.402  0.511  1.0
  O  O28  1  0.566  0.754  0.276  1.0
  O  O29  1  0.817  0.191  0.796  1.0
  O  O30  1  0.183  0.809  0.204  1.0
  O  O31  1  0.434  0.246  0.724  1.0
  O  O32  1  0.290  0.598  0.489  1.0
  O  O33  1  0.207  0.966  0.909  1.0
  O  O34  1  0.060  0.206  0.613  1.0
  O  O35  1  0.467  0.758  0.081  1.0
  O  O36  1  0.859  0.538  0.221  1.0
  O  O37  1  0.560  0.794  0.887  1.0
  O  O38  1  0.359  0.462  0.279  1.0
  O  O39  1  0.707  0.034  0.591  1.0
  O  O40  1  0.934  0.754  0.776  1.0
  O  O41  1  0.967  0.242  0.419  1.0
  O  O42  1  0.317  0.809  0.704  1.0
  O  O43  1  0.210  0.598  0.989  1.0
[/CIF]
.
The crystal structure described by LiFeP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a rectangular see-saw-like geometry to one O(4), one O(7), and two equivalent O(1) atoms. Fe(1) is bonded to one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Fe(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one P(1) and one P(2) atom. 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(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) 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 3-coordinate geometry to one Li(1), 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   6.196
_cell_length_b   7.511
_cell_length_c   12.579
_cell_angle_alpha   62.788
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   520.633
_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  0.116  0.325  0.047  1.0
  Li  Li1  1  0.616  0.675  0.453  1.0
  Li  Li2  1  0.384  0.325  0.547  1.0
  Li  Li3  1  0.884  0.675  0.953  1.0
  Fe  Fe4  1  0.377  0.207  0.268  1.0
  Fe  Fe5  1  0.123  0.207  0.768  1.0
  Fe  Fe6  1  0.877  0.793  0.232  1.0
  Fe  Fe7  1  0.623  0.793  0.732  1.0
  P  P8  1  0.112  0.689  0.716  1.0
  P  P9  1  0.649  0.223  0.040  1.0
  P  P10  1  0.149  0.777  0.460  1.0
  P  P11  1  0.612  0.311  0.784  1.0
  P  P12  1  0.388  0.689  0.216  1.0
  P  P13  1  0.851  0.223  0.540  1.0
  P  P14  1  0.351  0.777  0.960  1.0
  P  P15  1  0.888  0.311  0.284  1.0
  O  O16  1  0.790  0.402  0.011  1.0
  O  O17  1  0.683  0.191  0.296  1.0
  O  O18  1  0.033  0.758  0.581  1.0
  O  O19  1  0.066  0.246  0.224  1.0
  O  O20  1  0.293  0.966  0.409  1.0
  O  O21  1  0.641  0.538  0.721  1.0
  O  O22  1  0.440  0.206  0.113  1.0
  O  O23  1  0.141  0.462  0.779  1.0
  O  O24  1  0.533  0.242  0.919  1.0
  O  O25  1  0.940  0.794  0.387  1.0
  O  O26  1  0.793  0.034  0.091  1.0
  O  O27  1  0.710  0.402  0.511  1.0
  O  O28  1  0.566  0.754  0.276  1.0
  O  O29  1  0.817  0.191  0.796  1.0
  O  O30  1  0.183  0.809  0.204  1.0
  O  O31  1  0.434  0.246  0.724  1.0
  O  O32  1  0.290  0.598  0.489  1.0
  O  O33  1  0.207  0.966  0.909  1.0
  O  O34  1  0.060  0.206  0.613  1.0
  O  O35  1  0.467  0.758  0.081  1.0
  O  O36  1  0.859  0.538  0.221  1.0
  O  O37  1  0.560  0.794  0.887  1.0
  O  O38  1  0.359  0.462  0.279  1.0
  O  O39  1  0.707  0.034  0.591  1.0
  O  O40  1  0.934  0.754  0.776  1.0
  O  O41  1  0.967  0.242  0.419  1.0
  O  O42  1  0.317  0.809  0.704  1.0
  O  O43  1  0.210  0.598  0.989  1.0
[/CIF]
.