The compound described by Li2Fe3(P2O7)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(12), one O(2), one O(4), and two equivalent O(10) atoms. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(10), one O(12), and one O(4) atom. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(13), one O(5), one O(7), one O(9), and two equivalent O(6) atoms to form distorted FeO6 pentagonal pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent P(4)O4 tetrahedra, edges with two equivalent Fe(3)O6 octahedra, and  an edgeedge with one Fe(1)O6 pentagonal pyramid. In the second Fe site, Fe(2) is bonded to one O(1), one O(12), one O(14), one O(2), one O(3), and one O(4) atom to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(1), one O(13), one O(3), one O(5), one O(7), and one O(9) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Fe(1)O6 pentagonal pyramids. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the second P site, P(2) is bonded to one O(11), one O(14), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-53°. In the third P site, P(3) is bonded to one O(10), one O(12), one O(2), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-56°. In the fourth P site, P(4) is bonded to one O(11), one O(13), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with four equivalent Fe(1)O6 pentagonal pyramids, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one P(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one P(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one P(1) and one P(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(3), and one P(4) atom. In the tenth O site, O(10) is bonded to one Li(2), two equivalent Li(1), and one P(3) atom to form edge-sharing OLi3P trigonal pyramids. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one P(2) and one P(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one P(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(2) atom. is represented by the CIF file [CIF]
data_Li2Fe3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.294
_cell_length_b   6.609
_cell_length_c   16.032
_cell_angle_alpha   81.550
_cell_angle_beta   82.377
_cell_angle_gamma   72.019
_symmetry_Int_Tables_number   1
_cell_volume   525.422
_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  0.068  0.233  0.991  1.0
  Li  Li1  1  0.363  0.696  0.120  1.0
  Li  Li2  1  0.637  0.304  0.880  1.0
  Li  Li3  1  0.932  0.767  0.009  1.0
  Fe  Fe4  1  0.162  0.288  0.576  1.0
  Fe  Fe5  1  0.035  0.624  0.812  1.0
  Fe  Fe6  1  0.253  0.971  0.333  1.0
  Fe  Fe7  1  0.747  0.029  0.667  1.0
  Fe  Fe8  1  0.965  0.376  0.188  1.0
  Fe  Fe9  1  0.838  0.712  0.424  1.0
  P  P10  1  0.166  0.093  0.788  1.0
  P  P11  1  0.369  0.443  0.318  1.0
  P  P12  1  0.563  0.248  0.075  1.0
  P  P13  1  0.281  0.782  0.538  1.0
  P  P14  1  0.719  0.218  0.462  1.0
  P  P15  1  0.437  0.752  0.925  1.0
  P  P16  1  0.631  0.557  0.682  1.0
  P  P17  1  0.834  0.907  0.212  1.0
  O  O18  1  0.029  0.033  0.221  1.0
  O  O19  1  0.256  0.329  0.077  1.0
  O  O20  1  0.216  0.303  0.290  1.0
  O  O21  1  0.023  0.284  0.840  1.0
  O  O22  1  0.181  0.660  0.341  1.0
  O  O23  1  0.137  0.616  0.534  1.0
  O  O24  1  0.330  0.142  0.706  1.0
  O  O25  1  0.606  0.061  0.154  1.0
  O  O26  1  0.107  0.975  0.581  1.0
  O  O27  1  0.708  0.143  0.995  1.0
  O  O28  1  0.464  0.321  0.408  1.0
  O  O29  1  0.315  0.579  0.910  1.0
  O  O30  1  0.574  0.159  0.548  1.0
  O  O31  1  0.602  0.469  0.257  1.0
  O  O32  1  0.398  0.531  0.743  1.0
  O  O33  1  0.426  0.841  0.452  1.0
  O  O34  1  0.685  0.421  0.090  1.0
  O  O35  1  0.536  0.679  0.592  1.0
  O  O36  1  0.292  0.857  0.005  1.0
  O  O37  1  0.893  0.025  0.419  1.0
  O  O38  1  0.394  0.939  0.846  1.0
  O  O39  1  0.670  0.858  0.294  1.0
  O  O40  1  0.863  0.384  0.466  1.0
  O  O41  1  0.819  0.340  0.659  1.0
  O  O42  1  0.977  0.716  0.160  1.0
  O  O43  1  0.784  0.697  0.710  1.0
  O  O44  1  0.744  0.671  0.923  1.0
  O  O45  1  0.971  0.967  0.779  1.0
[/CIF]
.
The compound described by Li2Fe3(P2O7)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(12), one O(2), one O(4), and two equivalent O(10) atoms. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(10), one O(12), and one O(4) atom. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(13), one O(5), one O(7), one O(9), and two equivalent O(6) atoms to form distorted FeO6 pentagonal pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent P(4)O4 tetrahedra, edges with two equivalent Fe(3)O6 octahedra, and  an edgeedge with one Fe(1)O6 pentagonal pyramid. In the second Fe site, Fe(2) is bonded to one O(1), one O(12), one O(14), one O(2), one O(3), and one O(4) atom to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one Fe(3)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(1), one O(13), one O(3), one O(5), one O(7), and one O(9) atom to form distorted FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Fe(1)O6 pentagonal pyramids. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the second P site, P(2) is bonded to one O(11), one O(14), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-53°. In the third P site, P(3) is bonded to one O(10), one O(12), one O(2), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-56°. In the fourth P site, P(4) is bonded to one O(11), one O(13), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with four equivalent Fe(1)O6 pentagonal pyramids, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one P(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one P(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one P(1) and one P(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(3), and one P(4) atom. In the tenth O site, O(10) is bonded to one Li(2), two equivalent Li(1), and one P(3) atom to form edge-sharing OLi3P trigonal pyramids. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one P(2) and one P(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one P(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(2) atom. is represented by the CIF file [CIF]
data_Li2Fe3(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.294
_cell_length_b   6.609
_cell_length_c   16.032
_cell_angle_alpha   81.550
_cell_angle_beta   82.377
_cell_angle_gamma   72.019
_symmetry_Int_Tables_number   1
_cell_volume   525.422
_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  0.068  0.233  0.991  1.0
  Li  Li1  1  0.363  0.696  0.120  1.0
  Li  Li2  1  0.637  0.304  0.880  1.0
  Li  Li3  1  0.932  0.767  0.009  1.0
  Fe  Fe4  1  0.162  0.288  0.576  1.0
  Fe  Fe5  1  0.035  0.624  0.812  1.0
  Fe  Fe6  1  0.253  0.971  0.333  1.0
  Fe  Fe7  1  0.747  0.029  0.667  1.0
  Fe  Fe8  1  0.965  0.376  0.188  1.0
  Fe  Fe9  1  0.838  0.712  0.424  1.0
  P  P10  1  0.166  0.093  0.788  1.0
  P  P11  1  0.369  0.443  0.318  1.0
  P  P12  1  0.563  0.248  0.075  1.0
  P  P13  1  0.281  0.782  0.538  1.0
  P  P14  1  0.719  0.218  0.462  1.0
  P  P15  1  0.437  0.752  0.925  1.0
  P  P16  1  0.631  0.557  0.682  1.0
  P  P17  1  0.834  0.907  0.212  1.0
  O  O18  1  0.029  0.033  0.221  1.0
  O  O19  1  0.256  0.329  0.077  1.0
  O  O20  1  0.216  0.303  0.290  1.0
  O  O21  1  0.023  0.284  0.840  1.0
  O  O22  1  0.181  0.660  0.341  1.0
  O  O23  1  0.137  0.616  0.534  1.0
  O  O24  1  0.330  0.142  0.706  1.0
  O  O25  1  0.606  0.061  0.154  1.0
  O  O26  1  0.107  0.975  0.581  1.0
  O  O27  1  0.708  0.143  0.995  1.0
  O  O28  1  0.464  0.321  0.408  1.0
  O  O29  1  0.315  0.579  0.910  1.0
  O  O30  1  0.574  0.159  0.548  1.0
  O  O31  1  0.602  0.469  0.257  1.0
  O  O32  1  0.398  0.531  0.743  1.0
  O  O33  1  0.426  0.841  0.452  1.0
  O  O34  1  0.685  0.421  0.090  1.0
  O  O35  1  0.536  0.679  0.592  1.0
  O  O36  1  0.292  0.857  0.005  1.0
  O  O37  1  0.893  0.025  0.419  1.0
  O  O38  1  0.394  0.939  0.846  1.0
  O  O39  1  0.670  0.858  0.294  1.0
  O  O40  1  0.863  0.384  0.466  1.0
  O  O41  1  0.819  0.340  0.659  1.0
  O  O42  1  0.977  0.716  0.160  1.0
  O  O43  1  0.784  0.697  0.710  1.0
  O  O44  1  0.744  0.671  0.923  1.0
  O  O45  1  0.971  0.967  0.779  1.0
[/CIF]
.