The material structure described by Li2FeP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), and two equivalent O(1) atoms. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), one O(7), and two equivalent O(5) atoms. Fe(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form corner-sharing PO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Fe(1), 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(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) 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(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Li(2), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(2), 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   5.163
_cell_length_b   8.060
_cell_length_c   14.314
_cell_angle_alpha   67.889
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   551.884
_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  0.212  0.970  0.677  1.0
  Li  Li1  1  0.288  0.970  0.177  1.0
  Li  Li2  1  0.749  0.425  0.838  1.0
  Li  Li3  1  0.249  0.575  0.662  1.0
  Li  Li4  1  0.751  0.425  0.338  1.0
  Li  Li5  1  0.251  0.575  0.162  1.0
  Li  Li6  1  0.712  0.030  0.823  1.0
  Li  Li7  1  0.788  0.030  0.323  1.0
  Fe  Fe8  1  0.283  0.721  0.879  1.0
  Fe  Fe9  1  0.217  0.721  0.379  1.0
  Fe  Fe10  1  0.783  0.279  0.621  1.0
  Fe  Fe11  1  0.717  0.279  0.121  1.0
  P  P12  1  0.716  0.815  0.693  1.0
  P  P13  1  0.720  0.706  0.522  1.0
  P  P14  1  0.784  0.815  0.193  1.0
  P  P15  1  0.220  0.294  0.978  1.0
  P  P16  1  0.780  0.706  0.022  1.0
  P  P17  1  0.216  0.185  0.807  1.0
  P  P18  1  0.280  0.294  0.478  1.0
  P  P19  1  0.284  0.185  0.307  1.0
  O  O20  1  0.252  0.996  0.805  1.0
  O  O21  1  0.248  0.996  0.305  1.0
  O  O22  1  0.656  0.794  0.919  1.0
  O  O23  1  0.767  0.852  0.575  1.0
  O  O24  1  0.433  0.752  0.716  1.0
  O  O25  1  0.916  0.681  0.757  1.0
  O  O26  1  0.426  0.679  0.518  1.0
  O  O27  1  0.844  0.794  0.419  1.0
  O  O28  1  0.733  0.852  0.075  1.0
  O  O29  1  0.365  0.462  0.908  1.0
  O  O30  1  0.067  0.752  0.216  1.0
  O  O31  1  0.584  0.681  0.257  1.0
  O  O32  1  0.865  0.538  0.592  1.0
  O  O33  1  0.074  0.679  0.018  1.0
  O  O34  1  0.926  0.321  0.982  1.0
  O  O35  1  0.135  0.462  0.408  1.0
  O  O36  1  0.416  0.319  0.743  1.0
  O  O37  1  0.933  0.248  0.784  1.0
  O  O38  1  0.635  0.538  0.092  1.0
  O  O39  1  0.267  0.148  0.925  1.0
  O  O40  1  0.156  0.206  0.581  1.0
  O  O41  1  0.574  0.321  0.482  1.0
  O  O42  1  0.084  0.319  0.243  1.0
  O  O43  1  0.567  0.248  0.284  1.0
  O  O44  1  0.233  0.148  0.425  1.0
  O  O45  1  0.344  0.206  0.081  1.0
  O  O46  1  0.752  0.004  0.695  1.0
  O  O47  1  0.748  0.004  0.195  1.0
[/CIF]
.
The material structure described by Li2FeP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), and two equivalent O(1) atoms. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), one O(7), and two equivalent O(5) atoms. Fe(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form corner-sharing PO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Fe(1), 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(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) 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(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Li(2), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(2), 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   5.163
_cell_length_b   8.060
_cell_length_c   14.314
_cell_angle_alpha   67.889
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   551.884
_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  0.212  0.970  0.677  1.0
  Li  Li1  1  0.288  0.970  0.177  1.0
  Li  Li2  1  0.749  0.425  0.838  1.0
  Li  Li3  1  0.249  0.575  0.662  1.0
  Li  Li4  1  0.751  0.425  0.338  1.0
  Li  Li5  1  0.251  0.575  0.162  1.0
  Li  Li6  1  0.712  0.030  0.823  1.0
  Li  Li7  1  0.788  0.030  0.323  1.0
  Fe  Fe8  1  0.283  0.721  0.879  1.0
  Fe  Fe9  1  0.217  0.721  0.379  1.0
  Fe  Fe10  1  0.783  0.279  0.621  1.0
  Fe  Fe11  1  0.717  0.279  0.121  1.0
  P  P12  1  0.716  0.815  0.693  1.0
  P  P13  1  0.720  0.706  0.522  1.0
  P  P14  1  0.784  0.815  0.193  1.0
  P  P15  1  0.220  0.294  0.978  1.0
  P  P16  1  0.780  0.706  0.022  1.0
  P  P17  1  0.216  0.185  0.807  1.0
  P  P18  1  0.280  0.294  0.478  1.0
  P  P19  1  0.284  0.185  0.307  1.0
  O  O20  1  0.252  0.996  0.805  1.0
  O  O21  1  0.248  0.996  0.305  1.0
  O  O22  1  0.656  0.794  0.919  1.0
  O  O23  1  0.767  0.852  0.575  1.0
  O  O24  1  0.433  0.752  0.716  1.0
  O  O25  1  0.916  0.681  0.757  1.0
  O  O26  1  0.426  0.679  0.518  1.0
  O  O27  1  0.844  0.794  0.419  1.0
  O  O28  1  0.733  0.852  0.075  1.0
  O  O29  1  0.365  0.462  0.908  1.0
  O  O30  1  0.067  0.752  0.216  1.0
  O  O31  1  0.584  0.681  0.257  1.0
  O  O32  1  0.865  0.538  0.592  1.0
  O  O33  1  0.074  0.679  0.018  1.0
  O  O34  1  0.926  0.321  0.982  1.0
  O  O35  1  0.135  0.462  0.408  1.0
  O  O36  1  0.416  0.319  0.743  1.0
  O  O37  1  0.933  0.248  0.784  1.0
  O  O38  1  0.635  0.538  0.092  1.0
  O  O39  1  0.267  0.148  0.925  1.0
  O  O40  1  0.156  0.206  0.581  1.0
  O  O41  1  0.574  0.321  0.482  1.0
  O  O42  1  0.084  0.319  0.243  1.0
  O  O43  1  0.567  0.248  0.284  1.0
  O  O44  1  0.233  0.148  0.425  1.0
  O  O45  1  0.344  0.206  0.081  1.0
  O  O46  1  0.752  0.004  0.695  1.0
  O  O47  1  0.748  0.004  0.195  1.0
[/CIF]
.