The material described by Li2FeP2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-73°. In the second Li site, Li(2) is bonded to one O(1), one O(5), and two equivalent O(6) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 67-76°. Fe(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted FeO6 octahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), 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, corners with two equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-63°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-57°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a 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 3-coordinate geometry to one Li(1), one Fe(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(2), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.102
_cell_length_b   7.052
_cell_length_c   8.302
_cell_angle_alpha   66.691
_cell_angle_beta   87.999
_cell_angle_gamma   89.281
_symmetry_Int_Tables_number   1
_cell_volume   274.163
_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  0.767  0.762  0.280  1.0
  Fe  Fe1  1  0.233  0.238  0.720  1.0
  Li  Li2  1  0.231  0.802  0.564  1.0
  Li  Li3  1  0.769  0.198  0.435  1.0
  Li  Li4  1  0.294  0.841  0.995  1.0
  Li  Li5  1  0.706  0.159  0.005  1.0
  O  O6  1  0.078  0.919  0.782  1.0
  O  O7  1  0.922  0.081  0.218  1.0
  O  O8  1  0.282  0.350  0.155  1.0
  O  O9  1  0.719  0.650  0.845  1.0
  O  O10  1  0.573  0.473  0.332  1.0
  O  O11  1  0.427  0.527  0.668  1.0
  O  O12  1  0.613  0.035  0.677  1.0
  O  O13  1  0.387  0.966  0.323  1.0
  O  O14  1  0.859  0.345  0.785  1.0
  O  O15  1  0.141  0.655  0.215  1.0
  O  O16  1  0.697  0.875  0.004  1.0
  O  O17  1  0.303  0.125  0.996  1.0
  O  O18  1  0.134  0.295  0.465  1.0
  O  O19  1  0.865  0.705  0.535  1.0
  P  P20  1  0.219  0.116  0.179  1.0
  P  P21  1  0.781  0.884  0.821  1.0
  P  P22  1  0.718  0.551  0.698  1.0
  P  P23  1  0.282  0.449  0.302  1.0
[/CIF]
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The material described by Li2FeP2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-73°. In the second Li site, Li(2) is bonded to one O(1), one O(5), and two equivalent O(6) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 67-76°. Fe(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted FeO6 octahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), 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, corners with two equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-63°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-57°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a 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 3-coordinate geometry to one Li(1), one Fe(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(2), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.102
_cell_length_b   7.052
_cell_length_c   8.302
_cell_angle_alpha   66.691
_cell_angle_beta   87.999
_cell_angle_gamma   89.281
_symmetry_Int_Tables_number   1
_cell_volume   274.163
_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  0.767  0.762  0.280  1.0
  Fe  Fe1  1  0.233  0.238  0.720  1.0
  Li  Li2  1  0.231  0.802  0.564  1.0
  Li  Li3  1  0.769  0.198  0.435  1.0
  Li  Li4  1  0.294  0.841  0.995  1.0
  Li  Li5  1  0.706  0.159  0.005  1.0
  O  O6  1  0.078  0.919  0.782  1.0
  O  O7  1  0.922  0.081  0.218  1.0
  O  O8  1  0.282  0.350  0.155  1.0
  O  O9  1  0.719  0.650  0.845  1.0
  O  O10  1  0.573  0.473  0.332  1.0
  O  O11  1  0.427  0.527  0.668  1.0
  O  O12  1  0.613  0.035  0.677  1.0
  O  O13  1  0.387  0.966  0.323  1.0
  O  O14  1  0.859  0.345  0.785  1.0
  O  O15  1  0.141  0.655  0.215  1.0
  O  O16  1  0.697  0.875  0.004  1.0
  O  O17  1  0.303  0.125  0.996  1.0
  O  O18  1  0.134  0.295  0.465  1.0
  O  O19  1  0.865  0.705  0.535  1.0
  P  P20  1  0.219  0.116  0.179  1.0
  P  P21  1  0.781  0.884  0.821  1.0
  P  P22  1  0.718  0.551  0.698  1.0
  P  P23  1  0.282  0.449  0.302  1.0
[/CIF]
.