The structure described by Li2FeF4 crystallizes in the trigonal R-3 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(2), one F(4), and two equivalent F(1) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Li(2)F4 tetrahedra, and corners with four equivalent Fe(1)F5 trigonal bipyramids. In the second Li site, Li(2) is bonded to one F(2), one F(4), and two equivalent F(3) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Fe(1)F5 trigonal bipyramids, and  an edgeedge with one Fe(1)F5 trigonal bipyramid. Fe(1) is bonded to one F(1), one F(2), one F(4), and two equivalent F(3) atoms to form distorted FeF5 trigonal bipyramids that share corners with four equivalent Li(1)F4 tetrahedra, corners with four equivalent Li(2)F4 tetrahedra,  an edgeedge with one Li(2)F4 tetrahedra, and  an edgeedge with one Fe(1)F5 trigonal bipyramid. There are four inequivalent F sites. In the first F site, F(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. In the third F site, F(3) is bonded to two equivalent Li(2) and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing FLi2Fe2 tetrahedra. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. is represented by the CIF file [CIF]
data_Li2FeF4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.901
_cell_length_b   8.901
_cell_length_c   8.901
_cell_angle_alpha   107.734
_cell_angle_beta   107.734
_cell_angle_gamma   107.734
_symmetry_Int_Tables_number   1
_cell_volume   575.049
_cell_formula_units_Z   6
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  0.081  0.703  0.951  1.0
  Li  Li1  1  0.297  0.049  0.919  1.0
  Li  Li2  1  0.361  0.635  0.770  1.0
  Li  Li3  1  0.049  0.919  0.297  1.0
  Li  Li4  1  0.365  0.230  0.639  1.0
  Li  Li5  1  0.230  0.639  0.365  1.0
  Li  Li6  1  0.770  0.361  0.635  1.0
  Li  Li7  1  0.635  0.770  0.361  1.0
  Li  Li8  1  0.951  0.081  0.703  1.0
  Li  Li9  1  0.639  0.365  0.230  1.0
  Li  Li10  1  0.703  0.951  0.081  1.0
  Li  Li11  1  0.919  0.297  0.049  1.0
  Fe  Fe12  1  0.291  0.445  0.994  1.0
  Fe  Fe13  1  0.006  0.709  0.555  1.0
  Fe  Fe14  1  0.555  0.006  0.709  1.0
  Fe  Fe15  1  0.445  0.994  0.291  1.0
  Fe  Fe16  1  0.994  0.291  0.445  1.0
  Fe  Fe17  1  0.709  0.555  0.006  1.0
  F  F18  1  0.180  0.190  0.890  1.0
  F  F19  1  0.261  0.630  0.931  1.0
  F  F20  1  0.110  0.820  0.810  1.0
  F  F21  1  0.069  0.739  0.370  1.0
  F  F22  1  0.179  0.549  0.535  1.0
  F  F23  1  0.532  0.859  0.848  1.0
  F  F24  1  0.141  0.152  0.468  1.0
  F  F25  1  0.370  0.069  0.739  1.0
  F  F26  1  0.451  0.465  0.821  1.0
  F  F27  1  0.465  0.821  0.451  1.0
  F  F28  1  0.810  0.110  0.820  1.0
  F  F29  1  0.152  0.468  0.141  1.0
  F  F30  1  0.848  0.532  0.859  1.0
  F  F31  1  0.190  0.890  0.180  1.0
  F  F32  1  0.535  0.179  0.549  1.0
  F  F33  1  0.549  0.535  0.179  1.0
  F  F34  1  0.630  0.931  0.261  1.0
  F  F35  1  0.859  0.848  0.532  1.0
  F  F36  1  0.468  0.141  0.152  1.0
  F  F37  1  0.821  0.451  0.465  1.0
  F  F38  1  0.931  0.261  0.630  1.0
  F  F39  1  0.890  0.180  0.190  1.0
  F  F40  1  0.739  0.370  0.069  1.0
  F  F41  1  0.820  0.810  0.110  1.0
[/CIF]
.
The structure described by Li2FeF4 crystallizes in the trigonal R-3 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(2), one F(4), and two equivalent F(1) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Li(2)F4 tetrahedra, and corners with four equivalent Fe(1)F5 trigonal bipyramids. In the second Li site, Li(2) is bonded to one F(2), one F(4), and two equivalent F(3) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Fe(1)F5 trigonal bipyramids, and  an edgeedge with one Fe(1)F5 trigonal bipyramid. Fe(1) is bonded to one F(1), one F(2), one F(4), and two equivalent F(3) atoms to form distorted FeF5 trigonal bipyramids that share corners with four equivalent Li(1)F4 tetrahedra, corners with four equivalent Li(2)F4 tetrahedra,  an edgeedge with one Li(2)F4 tetrahedra, and  an edgeedge with one Fe(1)F5 trigonal bipyramid. There are four inequivalent F sites. In the first F site, F(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. In the third F site, F(3) is bonded to two equivalent Li(2) and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing FLi2Fe2 tetrahedra. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. is represented by the CIF file [CIF]
data_Li2FeF4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.901
_cell_length_b   8.901
_cell_length_c   8.901
_cell_angle_alpha   107.734
_cell_angle_beta   107.734
_cell_angle_gamma   107.734
_symmetry_Int_Tables_number   1
_cell_volume   575.049
_cell_formula_units_Z   6
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  0.081  0.703  0.951  1.0
  Li  Li1  1  0.297  0.049  0.919  1.0
  Li  Li2  1  0.361  0.635  0.770  1.0
  Li  Li3  1  0.049  0.919  0.297  1.0
  Li  Li4  1  0.365  0.230  0.639  1.0
  Li  Li5  1  0.230  0.639  0.365  1.0
  Li  Li6  1  0.770  0.361  0.635  1.0
  Li  Li7  1  0.635  0.770  0.361  1.0
  Li  Li8  1  0.951  0.081  0.703  1.0
  Li  Li9  1  0.639  0.365  0.230  1.0
  Li  Li10  1  0.703  0.951  0.081  1.0
  Li  Li11  1  0.919  0.297  0.049  1.0
  Fe  Fe12  1  0.291  0.445  0.994  1.0
  Fe  Fe13  1  0.006  0.709  0.555  1.0
  Fe  Fe14  1  0.555  0.006  0.709  1.0
  Fe  Fe15  1  0.445  0.994  0.291  1.0
  Fe  Fe16  1  0.994  0.291  0.445  1.0
  Fe  Fe17  1  0.709  0.555  0.006  1.0
  F  F18  1  0.180  0.190  0.890  1.0
  F  F19  1  0.261  0.630  0.931  1.0
  F  F20  1  0.110  0.820  0.810  1.0
  F  F21  1  0.069  0.739  0.370  1.0
  F  F22  1  0.179  0.549  0.535  1.0
  F  F23  1  0.532  0.859  0.848  1.0
  F  F24  1  0.141  0.152  0.468  1.0
  F  F25  1  0.370  0.069  0.739  1.0
  F  F26  1  0.451  0.465  0.821  1.0
  F  F27  1  0.465  0.821  0.451  1.0
  F  F28  1  0.810  0.110  0.820  1.0
  F  F29  1  0.152  0.468  0.141  1.0
  F  F30  1  0.848  0.532  0.859  1.0
  F  F31  1  0.190  0.890  0.180  1.0
  F  F32  1  0.535  0.179  0.549  1.0
  F  F33  1  0.549  0.535  0.179  1.0
  F  F34  1  0.630  0.931  0.261  1.0
  F  F35  1  0.859  0.848  0.532  1.0
  F  F36  1  0.468  0.141  0.152  1.0
  F  F37  1  0.821  0.451  0.465  1.0
  F  F38  1  0.931  0.261  0.630  1.0
  F  F39  1  0.890  0.180  0.190  1.0
  F  F40  1  0.739  0.370  0.069  1.0
  F  F41  1  0.820  0.810  0.110  1.0
[/CIF]
.