The material structure described by Li2FeSiO5 crystallizes in the orthorhombic Pmc2_1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  a cornercorner with one Fe(2)O5 trigonal bipyramid,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 45-46°. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO5 trigonal bipyramids that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles are 70°. In the second Fe site, Fe(2) is bonded to one O(6), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles are 68°. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with four equivalent Li(2)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and corners with two equivalent Fe(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 56-64°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(1), two equivalent Li(2), and one Fe(1) atom. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2FeSi trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Li(2), one Li(3), one Fe(2), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2FeSi tetrahedra. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one Fe(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Li(2), two equivalent Li(3), and one Fe(2) atom. is represented by the CIF card [CIF]
data_Li2FeSiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.550
_cell_length_b   9.074
_cell_length_c   9.155
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   377.974
_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  0.608  0.000  0.000  1.0
  Li  Li1  1  0.392  0.000  0.500  1.0
  Li  Li2  1  0.003  0.238  0.001  1.0
  Li  Li3  1  0.997  0.238  0.501  1.0
  Li  Li4  1  0.013  0.500  0.257  1.0
  Li  Li5  1  0.987  0.500  0.757  1.0
  Li  Li6  1  0.003  0.762  0.001  1.0
  Li  Li7  1  0.997  0.762  0.501  1.0
  Fe  Fe8  1  0.966  0.000  0.281  1.0
  Fe  Fe9  1  0.034  0.000  0.781  1.0
  Fe  Fe10  1  0.400  0.500  0.998  1.0
  Fe  Fe11  1  0.600  0.500  0.498  1.0
  Si  Si12  1  0.501  0.251  0.249  1.0
  Si  Si13  1  0.499  0.251  0.749  1.0
  Si  Si14  1  0.501  0.749  0.249  1.0
  Si  Si15  1  0.499  0.749  0.749  1.0
  O  O16  1  0.812  0.000  0.464  1.0
  O  O17  1  0.188  0.000  0.964  1.0
  O  O18  1  0.738  0.149  0.160  1.0
  O  O19  1  0.262  0.149  0.660  1.0
  O  O20  1  0.262  0.153  0.341  1.0
  O  O21  1  0.738  0.153  0.841  1.0
  O  O22  1  0.293  0.354  0.142  1.0
  O  O23  1  0.707  0.354  0.642  1.0
  O  O24  1  0.711  0.354  0.354  1.0
  O  O25  1  0.289  0.354  0.854  1.0
  O  O26  1  0.215  0.500  0.493  1.0
  O  O27  1  0.785  0.500  0.993  1.0
  O  O28  1  0.711  0.646  0.354  1.0
  O  O29  1  0.289  0.646  0.854  1.0
  O  O30  1  0.293  0.646  0.142  1.0
  O  O31  1  0.707  0.646  0.642  1.0
  O  O32  1  0.262  0.847  0.341  1.0
  O  O33  1  0.738  0.847  0.841  1.0
  O  O34  1  0.262  0.851  0.660  1.0
  O  O35  1  0.738  0.851  0.160  1.0
[/CIF]
.
The material structure described by Li2FeSiO5 crystallizes in the orthorhombic Pmc2_1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  a cornercorner with one Fe(2)O5 trigonal bipyramid,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 45-46°. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO5 trigonal bipyramids that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles are 70°. In the second Fe site, Fe(2) is bonded to one O(6), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles are 68°. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with four equivalent Li(2)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and corners with two equivalent Fe(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 56-64°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(1), two equivalent Li(2), and one Fe(1) atom. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2FeSi trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Li(2), one Li(3), one Fe(2), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2FeSi tetrahedra. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Li(3), one Fe(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Li(2), two equivalent Li(3), and one Fe(2) atom. is represented by the CIF card [CIF]
data_Li2FeSiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.550
_cell_length_b   9.074
_cell_length_c   9.155
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   377.974
_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  0.608  0.000  0.000  1.0
  Li  Li1  1  0.392  0.000  0.500  1.0
  Li  Li2  1  0.003  0.238  0.001  1.0
  Li  Li3  1  0.997  0.238  0.501  1.0
  Li  Li4  1  0.013  0.500  0.257  1.0
  Li  Li5  1  0.987  0.500  0.757  1.0
  Li  Li6  1  0.003  0.762  0.001  1.0
  Li  Li7  1  0.997  0.762  0.501  1.0
  Fe  Fe8  1  0.966  0.000  0.281  1.0
  Fe  Fe9  1  0.034  0.000  0.781  1.0
  Fe  Fe10  1  0.400  0.500  0.998  1.0
  Fe  Fe11  1  0.600  0.500  0.498  1.0
  Si  Si12  1  0.501  0.251  0.249  1.0
  Si  Si13  1  0.499  0.251  0.749  1.0
  Si  Si14  1  0.501  0.749  0.249  1.0
  Si  Si15  1  0.499  0.749  0.749  1.0
  O  O16  1  0.812  0.000  0.464  1.0
  O  O17  1  0.188  0.000  0.964  1.0
  O  O18  1  0.738  0.149  0.160  1.0
  O  O19  1  0.262  0.149  0.660  1.0
  O  O20  1  0.262  0.153  0.341  1.0
  O  O21  1  0.738  0.153  0.841  1.0
  O  O22  1  0.293  0.354  0.142  1.0
  O  O23  1  0.707  0.354  0.642  1.0
  O  O24  1  0.711  0.354  0.354  1.0
  O  O25  1  0.289  0.354  0.854  1.0
  O  O26  1  0.215  0.500  0.493  1.0
  O  O27  1  0.785  0.500  0.993  1.0
  O  O28  1  0.711  0.646  0.354  1.0
  O  O29  1  0.289  0.646  0.854  1.0
  O  O30  1  0.293  0.646  0.142  1.0
  O  O31  1  0.707  0.646  0.642  1.0
  O  O32  1  0.262  0.847  0.341  1.0
  O  O33  1  0.738  0.847  0.841  1.0
  O  O34  1  0.262  0.851  0.660  1.0
  O  O35  1  0.738  0.851  0.160  1.0
[/CIF]
.