The crystal structure described by Li3Fe2(SiO4)2 is Clathrate-derived structured and crystallizes in the monoclinic P2_1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form distorted LiO4 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, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(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 Fe(1)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Fe(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)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(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(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(3)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(4), one O(5), and one O(6) 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 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(2), one Fe(2), and one Si(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(3), one Fe(1), and one Si(2) 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 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(3), one Fe(2), and one Si(1) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(2) atom to form distorted corner-sharing OLi2FeSi tetrahedra. In the eighth O site, O(8) is bonded to one Li(1), one Li(3), one Fe(2), and one Si(2) atom to form distorted corner-sharing OLi2FeSi trigonal pyramids. is represented by the CIF file [CIF]
data_Li3Fe2(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.293
_cell_length_b   5.295
_cell_length_c   6.447
_cell_angle_alpha   90.633
_cell_angle_beta   90.605
_cell_angle_gamma   88.005
_symmetry_Int_Tables_number   1
_cell_volume   180.557
_cell_formula_units_Z   1
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  0.678  0.684  0.990  1.0
  Fe  Fe1  1  0.316  0.323  0.510  1.0
  Li  Li2  1  0.821  0.179  0.250  1.0
  Li  Li3  1  0.692  0.694  0.499  1.0
  Li  Li4  1  0.307  0.307  0.000  1.0
  O  O5  1  0.767  0.874  0.752  1.0
  O  O6  1  0.126  0.233  0.748  1.0
  O  O7  1  0.872  0.786  0.241  1.0
  O  O8  1  0.214  0.128  0.259  1.0
  O  O9  1  0.313  0.685  0.456  1.0
  O  O10  1  0.315  0.687  0.044  1.0
  O  O11  1  0.694  0.300  0.536  1.0
  O  O12  1  0.700  0.306  0.965  1.0
  Si  Si13  1  0.185  0.816  0.250  1.0
  Si  Si14  1  0.824  0.176  0.750  1.0
[/CIF]
.
The crystal structure described by Li3Fe2(SiO4)2 is Clathrate-derived structured and crystallizes in the monoclinic P2_1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form distorted LiO4 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, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(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 Fe(1)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Fe(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)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(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(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(3)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(4), one O(5), and one O(6) 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 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(2), one Fe(2), and one Si(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(3), one Fe(1), and one Si(2) 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 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(3), one Fe(2), and one Si(1) atom. In the seventh O site, O(7) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(2) atom to form distorted corner-sharing OLi2FeSi tetrahedra. In the eighth O site, O(8) is bonded to one Li(1), one Li(3), one Fe(2), and one Si(2) atom to form distorted corner-sharing OLi2FeSi trigonal pyramids. is represented by the CIF file [CIF]
data_Li3Fe2(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.293
_cell_length_b   5.295
_cell_length_c   6.447
_cell_angle_alpha   90.633
_cell_angle_beta   90.605
_cell_angle_gamma   88.005
_symmetry_Int_Tables_number   1
_cell_volume   180.557
_cell_formula_units_Z   1
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  0.678  0.684  0.990  1.0
  Fe  Fe1  1  0.316  0.323  0.510  1.0
  Li  Li2  1  0.821  0.179  0.250  1.0
  Li  Li3  1  0.692  0.694  0.499  1.0
  Li  Li4  1  0.307  0.307  0.000  1.0
  O  O5  1  0.767  0.874  0.752  1.0
  O  O6  1  0.126  0.233  0.748  1.0
  O  O7  1  0.872  0.786  0.241  1.0
  O  O8  1  0.214  0.128  0.259  1.0
  O  O9  1  0.313  0.685  0.456  1.0
  O  O10  1  0.315  0.687  0.044  1.0
  O  O11  1  0.694  0.300  0.536  1.0
  O  O12  1  0.700  0.306  0.965  1.0
  Si  Si13  1  0.185  0.816  0.250  1.0
  Si  Si14  1  0.824  0.176  0.750  1.0
[/CIF]
.