The compound described by Li3Fe2(SiO4)2 is Clathrate-derived structured and crystallizes in the monoclinic Pc space group. There are three 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 trigonal pyramids that share corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Fe(1)O4 tetrahedra, and  an edgeedge with one Si(2)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. In the third Li site, Li(3) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. In the second Fe site, Fe(2) is bonded to one O(3), one O(5), one O(7), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(2) atom to form edge-sharing OLi2FeSi trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Fe(2), and one Si(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the fourth O site, O(4) is bonded to one Li(1), one Li(3), one Fe(1), and one Si(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Li(2), one Fe(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Li(3), one Fe(1), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(3), one Fe(2), and one Si(2) atom to form a mixture of edge and corner-sharing OLi2FeSi trigonal pyramids. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Li(3), one Fe(2), and one Si(1) atom. is represented by the CIF file [CIF]
data_Li3Fe2(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.588
_cell_length_b   5.233
_cell_length_c   10.617
_cell_angle_alpha   89.413
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   366.012
_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
  Li  Li0  1  0.500  0.633  0.917  1.0
  Li  Li1  1  0.748  0.234  0.841  1.0
  Li  Li2  1  0.252  0.758  0.659  1.0
  Li  Li3  1  0.500  0.633  0.417  1.0
  Li  Li4  1  0.252  0.234  0.341  1.0
  Li  Li5  1  0.748  0.758  0.159  1.0
  Fe  Fe6  1  0.232  0.247  0.827  1.0
  Fe  Fe7  1  0.767  0.753  0.666  1.0
  Fe  Fe8  1  0.768  0.247  0.327  1.0
  Fe  Fe9  1  0.233  0.753  0.166  1.0
  Si  Si10  1  0.003  0.749  0.910  1.0
  Si  Si11  1  0.508  0.252  0.592  1.0
  Si  Si12  1  0.997  0.749  0.410  1.0
  Si  Si13  1  0.492  0.252  0.092  1.0
  O  O14  1  0.482  0.211  0.937  1.0
  O  O15  1  0.001  0.058  0.884  1.0
  O  O16  1  0.792  0.628  0.844  1.0
  O  O17  1  0.210  0.629  0.842  1.0
  O  O18  1  0.702  0.114  0.666  1.0
  O  O19  1  0.299  0.143  0.656  1.0
  O  O20  1  0.519  0.571  0.609  1.0
  O  O21  1  0.999  0.683  0.563  1.0
  O  O22  1  0.518  0.211  0.437  1.0
  O  O23  1  0.999  0.058  0.384  1.0
  O  O24  1  0.208  0.628  0.344  1.0
  O  O25  1  0.790  0.629  0.342  1.0
  O  O26  1  0.298  0.114  0.166  1.0
  O  O27  1  0.701  0.143  0.156  1.0
  O  O28  1  0.481  0.571  0.109  1.0
  O  O29  1  0.001  0.683  0.063  1.0
[/CIF]
.
The compound described by Li3Fe2(SiO4)2 is Clathrate-derived structured and crystallizes in the monoclinic Pc space group. There are three 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 trigonal pyramids that share corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Li(2)O4 tetrahedra,  an edgeedge with one Fe(1)O4 tetrahedra, and  an edgeedge with one Si(2)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. In the third Li site, Li(3) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. In the second Fe site, Fe(2) is bonded to one O(3), one O(5), one O(7), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(2) atom to form edge-sharing OLi2FeSi trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Fe(2), and one Si(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the fourth O site, O(4) is bonded to one Li(1), one Li(3), one Fe(1), and one Si(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Li(2), one Fe(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Li(3), one Fe(1), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(3), one Fe(2), and one Si(2) atom to form a mixture of edge and corner-sharing OLi2FeSi trigonal pyramids. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Li(3), one Fe(2), and one Si(1) atom. is represented by the CIF file [CIF]
data_Li3Fe2(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.588
_cell_length_b   5.233
_cell_length_c   10.617
_cell_angle_alpha   89.413
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   366.012
_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
  Li  Li0  1  0.500  0.633  0.917  1.0
  Li  Li1  1  0.748  0.234  0.841  1.0
  Li  Li2  1  0.252  0.758  0.659  1.0
  Li  Li3  1  0.500  0.633  0.417  1.0
  Li  Li4  1  0.252  0.234  0.341  1.0
  Li  Li5  1  0.748  0.758  0.159  1.0
  Fe  Fe6  1  0.232  0.247  0.827  1.0
  Fe  Fe7  1  0.767  0.753  0.666  1.0
  Fe  Fe8  1  0.768  0.247  0.327  1.0
  Fe  Fe9  1  0.233  0.753  0.166  1.0
  Si  Si10  1  0.003  0.749  0.910  1.0
  Si  Si11  1  0.508  0.252  0.592  1.0
  Si  Si12  1  0.997  0.749  0.410  1.0
  Si  Si13  1  0.492  0.252  0.092  1.0
  O  O14  1  0.482  0.211  0.937  1.0
  O  O15  1  0.001  0.058  0.884  1.0
  O  O16  1  0.792  0.628  0.844  1.0
  O  O17  1  0.210  0.629  0.842  1.0
  O  O18  1  0.702  0.114  0.666  1.0
  O  O19  1  0.299  0.143  0.656  1.0
  O  O20  1  0.519  0.571  0.609  1.0
  O  O21  1  0.999  0.683  0.563  1.0
  O  O22  1  0.518  0.211  0.437  1.0
  O  O23  1  0.999  0.058  0.384  1.0
  O  O24  1  0.208  0.628  0.344  1.0
  O  O25  1  0.790  0.629  0.342  1.0
  O  O26  1  0.298  0.114  0.166  1.0
  O  O27  1  0.701  0.143  0.156  1.0
  O  O28  1  0.481  0.571  0.109  1.0
  O  O29  1  0.001  0.683  0.063  1.0
[/CIF]
.