The material described by Li6Fe(SiO4)2 crystallizes in the triclinic P-1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form distorted LiO4 trigonal pyramids that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(3)O5 square pyramid, corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Li(3)O5 square pyramids,  an edgeedge with one Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 42-77°. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(4) atoms. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form distorted LiO5 square pyramids that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Li(1)O4 trigonal pyramid,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Li(3)O5 square pyramid, edges with two equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 38-52°. Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Li(3)O5 square pyramids, corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Li(1)O4 trigonal pyramids, edges with two equivalent Li(3)O5 square pyramids, and edges with two equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Li(3)O5 square pyramid, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O5 square pyramids, and  an edgeedge with one Li(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles are 50°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Li(1), one Li(2), one Li(3), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Li(3), two equivalent Li(2), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(3), one Fe(1), and one Si(1) atom to form distorted OLi3FeSi trigonal bipyramids that share  a cornercorner with one O(4)Li5Si octahedra,  a cornercorner with one O(3)Li3FeSi trigonal bipyramid, edges with two equivalent O(4)Li5Si octahedra, and  an edgeedge with one O(3)Li3FeSi trigonal bipyramid. The corner-sharing octahedral tilt angles are 24°. In the fourth O site, O(4) is bonded to one Li(3), two equivalent Li(1), two equivalent Li(2), and one Si(1) atom to form distorted OLi5Si octahedra that share  a cornercorner with one O(3)Li3FeSi trigonal bipyramid, edges with two equivalent O(4)Li5Si octahedra, and edges with two equivalent O(3)Li3FeSi trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li6Fe(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.150
_cell_length_b   5.544
_cell_length_c   6.235
_cell_angle_alpha   88.260
_cell_angle_beta   78.822
_cell_angle_gamma   85.588
_symmetry_Int_Tables_number   1
_cell_volume   174.109
_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  0.500  1.000  0.500  1.0
  Li  Li1  1  0.837  0.583  0.192  1.0
  Li  Li2  1  0.163  0.417  0.808  1.0
  Li  Li3  1  0.386  0.755  0.964  1.0
  Li  Li4  1  0.614  0.245  0.036  1.0
  Li  Li5  1  0.216  0.640  0.385  1.0
  Li  Li6  1  0.784  0.360  0.615  1.0
  O  O7  1  0.202  0.784  0.703  1.0
  O  O8  1  0.798  0.216  0.297  1.0
  O  O9  1  0.302  0.949  0.222  1.0
  O  O10  1  0.698  0.051  0.778  1.0
  O  O11  1  0.813  0.710  0.483  1.0
  O  O12  1  0.188  0.290  0.517  1.0
  O  O13  1  0.766  0.578  0.897  1.0
  O  O14  1  0.234  0.422  0.103  1.0
  Si  Si15  1  0.876  0.794  0.721  1.0
  Si  Si16  1  0.124  0.206  0.279  1.0
[/CIF]
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The material described by Li6Fe(SiO4)2 crystallizes in the triclinic P-1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form distorted LiO4 trigonal pyramids that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(3)O5 square pyramid, corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Li(3)O5 square pyramids,  an edgeedge with one Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 42-77°. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(4) atoms. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form distorted LiO5 square pyramids that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Li(1)O4 trigonal pyramid,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Li(3)O5 square pyramid, edges with two equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 38-52°. Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Li(3)O5 square pyramids, corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Li(1)O4 trigonal pyramids, edges with two equivalent Li(3)O5 square pyramids, and edges with two equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Li(3)O5 square pyramid, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O5 square pyramids, and  an edgeedge with one Li(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles are 50°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Li(1), one Li(2), one Li(3), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Li(3), two equivalent Li(2), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(3), one Fe(1), and one Si(1) atom to form distorted OLi3FeSi trigonal bipyramids that share  a cornercorner with one O(4)Li5Si octahedra,  a cornercorner with one O(3)Li3FeSi trigonal bipyramid, edges with two equivalent O(4)Li5Si octahedra, and  an edgeedge with one O(3)Li3FeSi trigonal bipyramid. The corner-sharing octahedral tilt angles are 24°. In the fourth O site, O(4) is bonded to one Li(3), two equivalent Li(1), two equivalent Li(2), and one Si(1) atom to form distorted OLi5Si octahedra that share  a cornercorner with one O(3)Li3FeSi trigonal bipyramid, edges with two equivalent O(4)Li5Si octahedra, and edges with two equivalent O(3)Li3FeSi trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li6Fe(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.150
_cell_length_b   5.544
_cell_length_c   6.235
_cell_angle_alpha   88.260
_cell_angle_beta   78.822
_cell_angle_gamma   85.588
_symmetry_Int_Tables_number   1
_cell_volume   174.109
_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  0.500  1.000  0.500  1.0
  Li  Li1  1  0.837  0.583  0.192  1.0
  Li  Li2  1  0.163  0.417  0.808  1.0
  Li  Li3  1  0.386  0.755  0.964  1.0
  Li  Li4  1  0.614  0.245  0.036  1.0
  Li  Li5  1  0.216  0.640  0.385  1.0
  Li  Li6  1  0.784  0.360  0.615  1.0
  O  O7  1  0.202  0.784  0.703  1.0
  O  O8  1  0.798  0.216  0.297  1.0
  O  O9  1  0.302  0.949  0.222  1.0
  O  O10  1  0.698  0.051  0.778  1.0
  O  O11  1  0.813  0.710  0.483  1.0
  O  O12  1  0.188  0.290  0.517  1.0
  O  O13  1  0.766  0.578  0.897  1.0
  O  O14  1  0.234  0.422  0.103  1.0
  Si  Si15  1  0.876  0.794  0.721  1.0
  Si  Si16  1  0.124  0.206  0.279  1.0
[/CIF]
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