The compound described by Li2Fe2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 2-coordinate geometry to one O(10) and two equivalent O(11) atoms. In the second Li site, Li(2) is bonded in a distorted linear geometry to one O(3) and one O(8) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one O(1), one O(2), one O(5), and one O(7) atom. In the second Fe site, Fe(2) is bonded in a distorted single-bond geometry to one O(11), one O(3), and one O(9) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Si site, Si(2) is bonded in a 3-coordinate geometry to one O(10), one O(11), one O(4), and one O(5) atom. In the third Si site, Si(3) is bonded in a 4-coordinate geometry to one O(2), one O(5), one O(6), and one O(8) atom. In the fourth Si site, Si(4) is bonded in a 4-coordinate geometry to one O(10), one O(6), one O(7), and one O(9) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Fe(1) and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one Si(2), and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Li(2) and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Fe(2) and one Si(4) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(1), one Si(2), and one Si(4) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Fe(2), and one Si(2) atom. is represented by the CIF card [CIF]
data_Li2Fe2Si4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.621
_cell_length_b   7.656
_cell_length_c   7.077
_cell_angle_alpha   110.938
_cell_angle_beta   101.835
_cell_angle_gamma   97.391
_symmetry_Int_Tables_number   1
_cell_volume   464.730
_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
  Li  Li0  1  0.911  0.436  0.588  1.0
  Li  Li1  1  0.374  0.446  0.617  1.0
  Li  Li2  1  0.626  0.554  0.383  1.0
  Li  Li3  1  0.089  0.564  0.412  1.0
  Fe  Fe4  1  0.669  0.245  0.774  1.0
  Fe  Fe5  1  0.112  0.210  0.656  1.0
  Fe  Fe6  1  0.888  0.790  0.344  1.0
  Fe  Fe7  1  0.331  0.755  0.226  1.0
  Si  Si8  1  0.247  0.051  0.368  1.0
  Si  Si9  1  0.953  0.240  0.224  1.0
  Si  Si10  1  0.528  0.233  0.224  1.0
  Si  Si11  1  0.780  0.600  0.974  1.0
  Si  Si12  1  0.220  0.400  0.026  1.0
  Si  Si13  1  0.472  0.767  0.776  1.0
  Si  Si14  1  0.047  0.760  0.776  1.0
  Si  Si15  1  0.753  0.949  0.632  1.0
  O  O16  1  0.816  0.125  0.648  1.0
  O  O17  1  0.410  0.079  0.261  1.0
  O  O18  1  0.339  0.150  0.589  1.0
  O  O19  1  0.025  0.088  0.244  1.0
  O  O20  1  0.695  0.193  0.133  1.0
  O  O21  1  0.356  0.277  0.043  1.0
  O  O22  1  0.650  0.448  0.818  1.0
  O  O23  1  0.623  0.360  0.414  1.0
  O  O24  1  0.142  0.409  0.803  1.0
  O  O25  1  0.004  0.313  0.056  1.0
  O  O26  1  0.064  0.350  0.433  1.0
  O  O27  1  0.936  0.650  0.567  1.0
  O  O28  1  0.996  0.687  0.944  1.0
  O  O29  1  0.858  0.591  0.197  1.0
  O  O30  1  0.377  0.640  0.586  1.0
  O  O31  1  0.350  0.552  0.182  1.0
  O  O32  1  0.644  0.723  0.957  1.0
  O  O33  1  0.305  0.807  0.867  1.0
  O  O34  1  0.975  0.912  0.756  1.0
  O  O35  1  0.661  0.850  0.411  1.0
  O  O36  1  0.590  0.921  0.739  1.0
  O  O37  1  0.184  0.875  0.352  1.0
[/CIF]
.
The compound described by Li2Fe2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 2-coordinate geometry to one O(10) and two equivalent O(11) atoms. In the second Li site, Li(2) is bonded in a distorted linear geometry to one O(3) and one O(8) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one O(1), one O(2), one O(5), and one O(7) atom. In the second Fe site, Fe(2) is bonded in a distorted single-bond geometry to one O(11), one O(3), and one O(9) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Si site, Si(2) is bonded in a 3-coordinate geometry to one O(10), one O(11), one O(4), and one O(5) atom. In the third Si site, Si(3) is bonded in a 4-coordinate geometry to one O(2), one O(5), one O(6), and one O(8) atom. In the fourth Si site, Si(4) is bonded in a 4-coordinate geometry to one O(10), one O(6), one O(7), and one O(9) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Fe(1) and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one Si(2), and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Li(2) and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Fe(2) and one Si(4) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(1), one Si(2), and one Si(4) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Fe(2), and one Si(2) atom. is represented by the CIF card [CIF]
data_Li2Fe2Si4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.621
_cell_length_b   7.656
_cell_length_c   7.077
_cell_angle_alpha   110.938
_cell_angle_beta   101.835
_cell_angle_gamma   97.391
_symmetry_Int_Tables_number   1
_cell_volume   464.730
_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
  Li  Li0  1  0.911  0.436  0.588  1.0
  Li  Li1  1  0.374  0.446  0.617  1.0
  Li  Li2  1  0.626  0.554  0.383  1.0
  Li  Li3  1  0.089  0.564  0.412  1.0
  Fe  Fe4  1  0.669  0.245  0.774  1.0
  Fe  Fe5  1  0.112  0.210  0.656  1.0
  Fe  Fe6  1  0.888  0.790  0.344  1.0
  Fe  Fe7  1  0.331  0.755  0.226  1.0
  Si  Si8  1  0.247  0.051  0.368  1.0
  Si  Si9  1  0.953  0.240  0.224  1.0
  Si  Si10  1  0.528  0.233  0.224  1.0
  Si  Si11  1  0.780  0.600  0.974  1.0
  Si  Si12  1  0.220  0.400  0.026  1.0
  Si  Si13  1  0.472  0.767  0.776  1.0
  Si  Si14  1  0.047  0.760  0.776  1.0
  Si  Si15  1  0.753  0.949  0.632  1.0
  O  O16  1  0.816  0.125  0.648  1.0
  O  O17  1  0.410  0.079  0.261  1.0
  O  O18  1  0.339  0.150  0.589  1.0
  O  O19  1  0.025  0.088  0.244  1.0
  O  O20  1  0.695  0.193  0.133  1.0
  O  O21  1  0.356  0.277  0.043  1.0
  O  O22  1  0.650  0.448  0.818  1.0
  O  O23  1  0.623  0.360  0.414  1.0
  O  O24  1  0.142  0.409  0.803  1.0
  O  O25  1  0.004  0.313  0.056  1.0
  O  O26  1  0.064  0.350  0.433  1.0
  O  O27  1  0.936  0.650  0.567  1.0
  O  O28  1  0.996  0.687  0.944  1.0
  O  O29  1  0.858  0.591  0.197  1.0
  O  O30  1  0.377  0.640  0.586  1.0
  O  O31  1  0.350  0.552  0.182  1.0
  O  O32  1  0.644  0.723  0.957  1.0
  O  O33  1  0.305  0.807  0.867  1.0
  O  O34  1  0.975  0.912  0.756  1.0
  O  O35  1  0.661  0.850  0.411  1.0
  O  O36  1  0.590  0.921  0.739  1.0
  O  O37  1  0.184  0.875  0.352  1.0
[/CIF]
.