The material described by LiFeP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(5), and one O(6) atom. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form FeO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with three equivalent Fe(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate 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 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. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Li(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. is represented by the CIF card [CIF]
data_LiFeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.065
_cell_length_b   4.949
_cell_length_c   14.204
_cell_angle_alpha   79.336
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   557.102
_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  0.858  0.953  0.379  1.0
  Li  Li1  1  0.358  0.047  0.121  1.0
  Li  Li2  1  0.642  0.953  0.879  1.0
  Li  Li3  1  0.142  0.047  0.621  1.0
  Fe  Fe4  1  0.764  0.671  0.689  1.0
  Fe  Fe5  1  0.264  0.329  0.811  1.0
  Fe  Fe6  1  0.736  0.671  0.189  1.0
  Fe  Fe7  1  0.236  0.329  0.311  1.0
  P  P8  1  0.718  0.262  0.044  1.0
  P  P9  1  0.471  0.843  0.322  1.0
  P  P10  1  0.971  0.157  0.178  1.0
  P  P11  1  0.218  0.738  0.456  1.0
  P  P12  1  0.782  0.262  0.544  1.0
  P  P13  1  0.029  0.843  0.822  1.0
  P  P14  1  0.529  0.157  0.678  1.0
  P  P15  1  0.282  0.738  0.956  1.0
  O  O16  1  0.551  0.843  0.708  1.0
  O  O17  1  0.854  0.310  0.236  1.0
  O  O18  1  0.321  0.452  0.930  1.0
  O  O19  1  0.133  0.967  0.382  1.0
  O  O20  1  0.153  0.245  0.186  1.0
  O  O21  1  0.195  0.757  0.558  1.0
  O  O22  1  0.920  0.229  0.067  1.0
  O  O23  1  0.420  0.771  0.433  1.0
  O  O24  1  0.695  0.243  0.942  1.0
  O  O25  1  0.653  0.755  0.314  1.0
  O  O26  1  0.633  0.033  0.118  1.0
  O  O27  1  0.821  0.548  0.570  1.0
  O  O28  1  0.354  0.690  0.264  1.0
  O  O29  1  0.051  0.157  0.792  1.0
  O  O30  1  0.949  0.843  0.208  1.0
  O  O31  1  0.646  0.310  0.736  1.0
  O  O32  1  0.179  0.452  0.430  1.0
  O  O33  1  0.367  0.967  0.882  1.0
  O  O34  1  0.347  0.245  0.686  1.0
  O  O35  1  0.305  0.757  0.058  1.0
  O  O36  1  0.580  0.229  0.567  1.0
  O  O37  1  0.080  0.771  0.933  1.0
  O  O38  1  0.805  0.243  0.442  1.0
  O  O39  1  0.847  0.755  0.814  1.0
  O  O40  1  0.867  0.033  0.618  1.0
  O  O41  1  0.679  0.548  0.070  1.0
  O  O42  1  0.146  0.690  0.764  1.0
  O  O43  1  0.449  0.157  0.292  1.0
[/CIF]
.
The material described by LiFeP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(5), and one O(6) atom. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form FeO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with three equivalent Fe(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate 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 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. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Li(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. is represented by the CIF card [CIF]
data_LiFeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.065
_cell_length_b   4.949
_cell_length_c   14.204
_cell_angle_alpha   79.336
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   557.102
_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  0.858  0.953  0.379  1.0
  Li  Li1  1  0.358  0.047  0.121  1.0
  Li  Li2  1  0.642  0.953  0.879  1.0
  Li  Li3  1  0.142  0.047  0.621  1.0
  Fe  Fe4  1  0.764  0.671  0.689  1.0
  Fe  Fe5  1  0.264  0.329  0.811  1.0
  Fe  Fe6  1  0.736  0.671  0.189  1.0
  Fe  Fe7  1  0.236  0.329  0.311  1.0
  P  P8  1  0.718  0.262  0.044  1.0
  P  P9  1  0.471  0.843  0.322  1.0
  P  P10  1  0.971  0.157  0.178  1.0
  P  P11  1  0.218  0.738  0.456  1.0
  P  P12  1  0.782  0.262  0.544  1.0
  P  P13  1  0.029  0.843  0.822  1.0
  P  P14  1  0.529  0.157  0.678  1.0
  P  P15  1  0.282  0.738  0.956  1.0
  O  O16  1  0.551  0.843  0.708  1.0
  O  O17  1  0.854  0.310  0.236  1.0
  O  O18  1  0.321  0.452  0.930  1.0
  O  O19  1  0.133  0.967  0.382  1.0
  O  O20  1  0.153  0.245  0.186  1.0
  O  O21  1  0.195  0.757  0.558  1.0
  O  O22  1  0.920  0.229  0.067  1.0
  O  O23  1  0.420  0.771  0.433  1.0
  O  O24  1  0.695  0.243  0.942  1.0
  O  O25  1  0.653  0.755  0.314  1.0
  O  O26  1  0.633  0.033  0.118  1.0
  O  O27  1  0.821  0.548  0.570  1.0
  O  O28  1  0.354  0.690  0.264  1.0
  O  O29  1  0.051  0.157  0.792  1.0
  O  O30  1  0.949  0.843  0.208  1.0
  O  O31  1  0.646  0.310  0.736  1.0
  O  O32  1  0.179  0.452  0.430  1.0
  O  O33  1  0.367  0.967  0.882  1.0
  O  O34  1  0.347  0.245  0.686  1.0
  O  O35  1  0.305  0.757  0.058  1.0
  O  O36  1  0.580  0.229  0.567  1.0
  O  O37  1  0.080  0.771  0.933  1.0
  O  O38  1  0.805  0.243  0.442  1.0
  O  O39  1  0.847  0.755  0.814  1.0
  O  O40  1  0.867  0.033  0.618  1.0
  O  O41  1  0.679  0.548  0.070  1.0
  O  O42  1  0.146  0.690  0.764  1.0
  O  O43  1  0.449  0.157  0.292  1.0
[/CIF]
.