The crystal structure described by Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. There are two 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(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. 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. is represented by the CIF file [CIF]
data_Li2FeSiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.406
_cell_length_b   5.405
_cell_length_c   6.226
_cell_angle_alpha   89.995
_cell_angle_beta   89.995
_cell_angle_gamma   86.978
_symmetry_Int_Tables_number   1
_cell_volume   181.669
_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
  Fe  Fe0  1  0.178  0.178  0.750  1.0
  Fe  Fe1  1  0.822  0.822  0.250  1.0
  Li  Li2  1  0.674  0.326  0.500  1.0
  Li  Li3  1  0.326  0.674  1.000  1.0
  Li  Li4  1  0.190  0.190  0.250  1.0
  Li  Li5  1  0.810  0.810  0.750  1.0
  O  O6  1  0.799  0.190  0.780  1.0
  O  O7  1  0.810  0.201  0.220  1.0
  O  O8  1  0.201  0.810  0.280  1.0
  O  O9  1  0.190  0.799  0.720  1.0
  O  O10  1  0.376  0.290  0.002  1.0
  O  O11  1  0.710  0.624  0.998  1.0
  O  O12  1  0.290  0.376  0.498  1.0
  O  O13  1  0.624  0.710  0.502  1.0
  Si  Si14  1  0.680  0.320  1.000  1.0
  Si  Si15  1  0.320  0.680  0.500  1.0
[/CIF]
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The crystal structure described by Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. There are two 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(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. 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. is represented by the CIF file [CIF]
data_Li2FeSiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.406
_cell_length_b   5.405
_cell_length_c   6.226
_cell_angle_alpha   89.995
_cell_angle_beta   89.995
_cell_angle_gamma   86.978
_symmetry_Int_Tables_number   1
_cell_volume   181.669
_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
  Fe  Fe0  1  0.178  0.178  0.750  1.0
  Fe  Fe1  1  0.822  0.822  0.250  1.0
  Li  Li2  1  0.674  0.326  0.500  1.0
  Li  Li3  1  0.326  0.674  1.000  1.0
  Li  Li4  1  0.190  0.190  0.250  1.0
  Li  Li5  1  0.810  0.810  0.750  1.0
  O  O6  1  0.799  0.190  0.780  1.0
  O  O7  1  0.810  0.201  0.220  1.0
  O  O8  1  0.201  0.810  0.280  1.0
  O  O9  1  0.190  0.799  0.720  1.0
  O  O10  1  0.376  0.290  0.002  1.0
  O  O11  1  0.710  0.624  0.998  1.0
  O  O12  1  0.290  0.376  0.498  1.0
  O  O13  1  0.624  0.710  0.502  1.0
  Si  Si14  1  0.680  0.320  1.000  1.0
  Si  Si15  1  0.320  0.680  0.500  1.0
[/CIF]
.