The material described by Li2Fe3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded in a square co-planar geometry to two equivalent O(5) and two equivalent O(6) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Li2Fe3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.036
_cell_length_b   7.836
_cell_length_c   9.178
_cell_angle_alpha   70.906
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   614.096
_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  0.529  0.734  0.842  1.0
  Li  Li1  1  0.471  0.266  0.158  1.0
  Li  Li2  1  0.971  0.734  0.342  1.0
  Li  Li3  1  0.029  0.266  0.658  1.0
  Fe  Fe4  1  0.716  0.513  0.543  1.0
  Fe  Fe5  1  0.284  0.487  0.457  1.0
  Fe  Fe6  1  0.216  0.487  0.957  1.0
  Fe  Fe7  1  0.784  0.513  0.043  1.0
  Fe  Fe8  1  0.000  0.000  0.000  1.0
  Fe  Fe9  1  0.500  0.000  0.500  1.0
  P  P10  1  0.295  0.899  0.241  1.0
  P  P11  1  0.705  0.101  0.759  1.0
  P  P12  1  0.523  0.624  0.220  1.0
  P  P13  1  0.477  0.376  0.780  1.0
  P  P14  1  0.023  0.376  0.280  1.0
  P  P15  1  0.205  0.899  0.741  1.0
  P  P16  1  0.977  0.624  0.720  1.0
  P  P17  1  0.795  0.101  0.259  1.0
  O  O18  1  0.411  0.372  0.936  1.0
  O  O19  1  0.078  0.801  0.670  1.0
  O  O20  1  0.925  0.546  0.213  1.0
  O  O21  1  0.638  0.639  0.337  1.0
  O  O22  1  0.383  0.032  0.300  1.0
  O  O23  1  0.862  0.639  0.837  1.0
  O  O24  1  0.193  0.993  0.108  1.0
  O  O25  1  0.138  0.361  0.163  1.0
  O  O26  1  0.575  0.546  0.713  1.0
  O  O27  1  0.307  0.993  0.608  1.0
  O  O28  1  0.617  0.968  0.700  1.0
  O  O29  1  0.117  0.032  0.800  1.0
  O  O30  1  0.786  0.253  0.633  1.0
  O  O31  1  0.911  0.628  0.564  1.0
  O  O32  1  0.578  0.199  0.830  1.0
  O  O33  1  0.693  0.007  0.392  1.0
  O  O34  1  0.089  0.372  0.436  1.0
  O  O35  1  0.714  0.253  0.133  1.0
  O  O36  1  0.422  0.801  0.170  1.0
  O  O37  1  0.362  0.361  0.663  1.0
  O  O38  1  0.589  0.628  0.064  1.0
  O  O39  1  0.286  0.747  0.867  1.0
  O  O40  1  0.807  0.007  0.892  1.0
  O  O41  1  0.883  0.968  0.200  1.0
  O  O42  1  0.922  0.199  0.330  1.0
  O  O43  1  0.075  0.454  0.787  1.0
  O  O44  1  0.214  0.747  0.367  1.0
  O  O45  1  0.425  0.454  0.287  1.0
[/CIF]
.
The material described by Li2Fe3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded in a square co-planar geometry to two equivalent O(5) and two equivalent O(6) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Li2Fe3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.036
_cell_length_b   7.836
_cell_length_c   9.178
_cell_angle_alpha   70.906
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   614.096
_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  0.529  0.734  0.842  1.0
  Li  Li1  1  0.471  0.266  0.158  1.0
  Li  Li2  1  0.971  0.734  0.342  1.0
  Li  Li3  1  0.029  0.266  0.658  1.0
  Fe  Fe4  1  0.716  0.513  0.543  1.0
  Fe  Fe5  1  0.284  0.487  0.457  1.0
  Fe  Fe6  1  0.216  0.487  0.957  1.0
  Fe  Fe7  1  0.784  0.513  0.043  1.0
  Fe  Fe8  1  0.000  0.000  0.000  1.0
  Fe  Fe9  1  0.500  0.000  0.500  1.0
  P  P10  1  0.295  0.899  0.241  1.0
  P  P11  1  0.705  0.101  0.759  1.0
  P  P12  1  0.523  0.624  0.220  1.0
  P  P13  1  0.477  0.376  0.780  1.0
  P  P14  1  0.023  0.376  0.280  1.0
  P  P15  1  0.205  0.899  0.741  1.0
  P  P16  1  0.977  0.624  0.720  1.0
  P  P17  1  0.795  0.101  0.259  1.0
  O  O18  1  0.411  0.372  0.936  1.0
  O  O19  1  0.078  0.801  0.670  1.0
  O  O20  1  0.925  0.546  0.213  1.0
  O  O21  1  0.638  0.639  0.337  1.0
  O  O22  1  0.383  0.032  0.300  1.0
  O  O23  1  0.862  0.639  0.837  1.0
  O  O24  1  0.193  0.993  0.108  1.0
  O  O25  1  0.138  0.361  0.163  1.0
  O  O26  1  0.575  0.546  0.713  1.0
  O  O27  1  0.307  0.993  0.608  1.0
  O  O28  1  0.617  0.968  0.700  1.0
  O  O29  1  0.117  0.032  0.800  1.0
  O  O30  1  0.786  0.253  0.633  1.0
  O  O31  1  0.911  0.628  0.564  1.0
  O  O32  1  0.578  0.199  0.830  1.0
  O  O33  1  0.693  0.007  0.392  1.0
  O  O34  1  0.089  0.372  0.436  1.0
  O  O35  1  0.714  0.253  0.133  1.0
  O  O36  1  0.422  0.801  0.170  1.0
  O  O37  1  0.362  0.361  0.663  1.0
  O  O38  1  0.589  0.628  0.064  1.0
  O  O39  1  0.286  0.747  0.867  1.0
  O  O40  1  0.807  0.007  0.892  1.0
  O  O41  1  0.883  0.968  0.200  1.0
  O  O42  1  0.922  0.199  0.330  1.0
  O  O43  1  0.075  0.454  0.787  1.0
  O  O44  1  0.214  0.747  0.367  1.0
  O  O45  1  0.425  0.454  0.287  1.0
[/CIF]
.