The structure described by Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the monoclinic P2_1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(7), and two equivalent O(3) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(8), and two equivalent O(4) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Fe(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(4)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), and one O(8) atom to form FeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with three equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Li(3), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(4), one Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the third O site, O(3) is bonded to two equivalent Li(1), one Fe(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Li(2), one Fe(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the fifth O site, O(5) is bonded to one Li(3), one Li(4), one Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the sixth O site, O(6) is bonded to one Li(3), one Li(4), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. 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 corner-sharing OLi2FeSi tetrahedra. In the eighth O site, O(8) is bonded to one Li(2), one Li(4), one Fe(1), and one Si(1) atom to form corner-sharing OLi2FeSi tetrahedra. is represented by the CIF file [CIF]
data_Li2FeSiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.105
_cell_length_b   8.347
_cell_length_c   8.325
_cell_angle_alpha   99.145
_cell_angle_beta   89.998
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   350.241
_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  0.594  0.421  0.917  1.0
  Li  Li1  1  0.676  0.921  0.417  1.0
  Li  Li2  1  0.094  0.579  0.083  1.0
  Li  Li3  1  0.176  0.079  0.583  1.0
  Li  Li4  1  0.078  0.336  0.335  1.0
  Li  Li5  1  0.692  0.164  0.165  1.0
  Li  Li6  1  0.578  0.664  0.665  1.0
  Li  Li7  1  0.192  0.836  0.835  1.0
  Fe  Fe8  1  0.187  0.207  0.957  1.0
  Fe  Fe9  1  0.583  0.293  0.542  1.0
  Fe  Fe10  1  0.687  0.793  0.043  1.0
  Fe  Fe11  1  0.083  0.707  0.458  1.0
  Si  Si12  1  0.692  0.040  0.791  1.0
  Si  Si13  1  0.577  0.541  0.292  1.0
  Si  Si14  1  0.192  0.960  0.209  1.0
  Si  Si15  1  0.077  0.459  0.708  1.0
  O  O16  1  0.172  0.313  0.561  1.0
  O  O17  1  0.672  0.687  0.439  1.0
  O  O18  1  0.098  0.814  0.062  1.0
  O  O19  1  0.598  0.186  0.938  1.0
  O  O20  1  0.695  0.572  0.114  1.0
  O  O21  1  0.574  0.072  0.614  1.0
  O  O22  1  0.074  0.928  0.386  1.0
  O  O23  1  0.195  0.428  0.886  1.0
  O  O24  1  0.086  0.137  0.170  1.0
  O  O25  1  0.586  0.863  0.830  1.0
  O  O26  1  0.683  0.363  0.330  1.0
  O  O27  1  0.183  0.637  0.670  1.0
  O  O28  1  0.754  0.464  0.716  1.0
  O  O29  1  0.016  0.035  0.784  1.0
  O  O30  1  0.516  0.965  0.216  1.0
  O  O31  1  0.254  0.536  0.284  1.0
[/CIF]
.
The structure described by Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the monoclinic P2_1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(7), and two equivalent O(3) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(8), and two equivalent O(4) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Fe(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(4)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(3)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), and one O(8) atom to form FeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with three equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Li(3), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(4), one Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the third O site, O(3) is bonded to two equivalent Li(1), one Fe(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Li(2), one Fe(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the fifth O site, O(5) is bonded to one Li(3), one Li(4), one Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. In the sixth O site, O(6) is bonded to one Li(3), one Li(4), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2FeSi tetrahedra. 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 corner-sharing OLi2FeSi tetrahedra. In the eighth O site, O(8) is bonded to one Li(2), one Li(4), one Fe(1), and one Si(1) atom to form corner-sharing OLi2FeSi tetrahedra. is represented by the CIF file [CIF]
data_Li2FeSiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.105
_cell_length_b   8.347
_cell_length_c   8.325
_cell_angle_alpha   99.145
_cell_angle_beta   89.998
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   350.241
_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  0.594  0.421  0.917  1.0
  Li  Li1  1  0.676  0.921  0.417  1.0
  Li  Li2  1  0.094  0.579  0.083  1.0
  Li  Li3  1  0.176  0.079  0.583  1.0
  Li  Li4  1  0.078  0.336  0.335  1.0
  Li  Li5  1  0.692  0.164  0.165  1.0
  Li  Li6  1  0.578  0.664  0.665  1.0
  Li  Li7  1  0.192  0.836  0.835  1.0
  Fe  Fe8  1  0.187  0.207  0.957  1.0
  Fe  Fe9  1  0.583  0.293  0.542  1.0
  Fe  Fe10  1  0.687  0.793  0.043  1.0
  Fe  Fe11  1  0.083  0.707  0.458  1.0
  Si  Si12  1  0.692  0.040  0.791  1.0
  Si  Si13  1  0.577  0.541  0.292  1.0
  Si  Si14  1  0.192  0.960  0.209  1.0
  Si  Si15  1  0.077  0.459  0.708  1.0
  O  O16  1  0.172  0.313  0.561  1.0
  O  O17  1  0.672  0.687  0.439  1.0
  O  O18  1  0.098  0.814  0.062  1.0
  O  O19  1  0.598  0.186  0.938  1.0
  O  O20  1  0.695  0.572  0.114  1.0
  O  O21  1  0.574  0.072  0.614  1.0
  O  O22  1  0.074  0.928  0.386  1.0
  O  O23  1  0.195  0.428  0.886  1.0
  O  O24  1  0.086  0.137  0.170  1.0
  O  O25  1  0.586  0.863  0.830  1.0
  O  O26  1  0.683  0.363  0.330  1.0
  O  O27  1  0.183  0.637  0.670  1.0
  O  O28  1  0.754  0.464  0.716  1.0
  O  O29  1  0.016  0.035  0.784  1.0
  O  O30  1  0.516  0.965  0.216  1.0
  O  O31  1  0.254  0.536  0.284  1.0
[/CIF]
.