The material described by Li2FeP2O7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. Fe(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(4) atoms. P(1) 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 two equivalent Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent P(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), and one P(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Li2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.583
_cell_length_b   7.585
_cell_length_c   7.586
_cell_angle_alpha   115.637
_cell_angle_beta   89.697
_cell_angle_gamma   89.697
_symmetry_Int_Tables_number   1
_cell_volume   289.605
_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  0.242  0.306  0.306  1.0
  Fe  Fe1  1  0.758  0.694  0.694  1.0
  Li  Li2  1  0.000  0.285  0.715  1.0
  Li  Li3  1  0.000  0.715  0.285  1.0
  Li  Li4  1  0.500  0.714  0.286  1.0
  Li  Li5  1  0.500  0.286  0.714  1.0
  O  O6  1  0.748  0.104  0.104  1.0
  O  O7  1  0.252  0.896  0.896  1.0
  O  O8  1  0.749  0.265  0.877  1.0
  O  O9  1  0.749  0.877  0.265  1.0
  O  O10  1  0.251  0.123  0.735  1.0
  O  O11  1  0.251  0.735  0.123  1.0
  O  O12  1  0.514  0.199  0.421  1.0
  O  O13  1  0.486  0.801  0.579  1.0
  O  O14  1  0.486  0.579  0.801  1.0
  O  O15  1  0.514  0.421  0.199  1.0
  O  O16  1  0.030  0.798  0.575  1.0
  O  O17  1  0.030  0.575  0.798  1.0
  O  O18  1  0.970  0.202  0.425  1.0
  O  O19  1  0.970  0.425  0.202  1.0
  P  P20  1  0.255  0.909  0.686  1.0
  P  P21  1  0.745  0.091  0.314  1.0
  P  P22  1  0.745  0.314  0.091  1.0
  P  P23  1  0.255  0.686  0.909  1.0
[/CIF]
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The material described by Li2FeP2O7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. Fe(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(4) atoms. P(1) 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 two equivalent Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent P(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), and one P(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_Li2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.583
_cell_length_b   7.585
_cell_length_c   7.586
_cell_angle_alpha   115.637
_cell_angle_beta   89.697
_cell_angle_gamma   89.697
_symmetry_Int_Tables_number   1
_cell_volume   289.605
_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  0.242  0.306  0.306  1.0
  Fe  Fe1  1  0.758  0.694  0.694  1.0
  Li  Li2  1  0.000  0.285  0.715  1.0
  Li  Li3  1  0.000  0.715  0.285  1.0
  Li  Li4  1  0.500  0.714  0.286  1.0
  Li  Li5  1  0.500  0.286  0.714  1.0
  O  O6  1  0.748  0.104  0.104  1.0
  O  O7  1  0.252  0.896  0.896  1.0
  O  O8  1  0.749  0.265  0.877  1.0
  O  O9  1  0.749  0.877  0.265  1.0
  O  O10  1  0.251  0.123  0.735  1.0
  O  O11  1  0.251  0.735  0.123  1.0
  O  O12  1  0.514  0.199  0.421  1.0
  O  O13  1  0.486  0.801  0.579  1.0
  O  O14  1  0.486  0.579  0.801  1.0
  O  O15  1  0.514  0.421  0.199  1.0
  O  O16  1  0.030  0.798  0.575  1.0
  O  O17  1  0.030  0.575  0.798  1.0
  O  O18  1  0.970  0.202  0.425  1.0
  O  O19  1  0.970  0.425  0.202  1.0
  P  P20  1  0.255  0.909  0.686  1.0
  P  P21  1  0.745  0.091  0.314  1.0
  P  P22  1  0.745  0.314  0.091  1.0
  P  P23  1  0.255  0.686  0.909  1.0
[/CIF]
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