The compound described by Li2Fe2Si8O19 crystallizes in the triclinic P1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 3-coordinate geometry to one O(16), one O(17), and one O(7) atom. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(12), one O(17), and one O(3) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(12), one O(13), one O(4), and one O(6) atom to form distorted FeO4 trigonal pyramids that share  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(13), one O(15), one O(6), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(6)O4 tetrahedra, and corners with two equivalent Fe(1)O4 trigonal pyramids. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(2), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(18), one O(19), one O(3), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(17), one O(3), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and corners with two equivalent Fe(1)O4 trigonal pyramids. In the fourth Si site, Si(4) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and  a cornercorner with one Si(8)O4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(10), one O(12), one O(14), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and  a cornercorner with one Fe(1)O4 trigonal pyramid. In the sixth Si site, Si(6) is bonded to one O(13), one O(15), one O(16), and one O(17) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and  a cornercorner with one Fe(1)O4 trigonal pyramid. In the seventh Si site, Si(7) is bonded to one O(1), one O(11), one O(16), and one O(2) atom to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(14), one O(18), one O(19), and one O(9) atom to form corner-sharing SiO4 tetrahedra. There are nineteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(7) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(7) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(2), and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Fe(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one Si(4) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Si(2) and one Si(5) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(8) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Si(4) and one Si(7) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(5) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(8) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one Si(6) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(6), and one Si(7) atom. In the seventeenth O site, O(17) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Si(3), and one Si(6) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(8) atom. In the nineteenth O site, O(19) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(8) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Fe2Si8O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.947
_cell_length_b   7.189
_cell_length_c   12.505
_cell_angle_alpha   72.899
_cell_angle_beta   89.969
_cell_angle_gamma   70.197
_symmetry_Int_Tables_number   1
_cell_volume   397.506
_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
  Li  Li0  1  0.758  0.804  0.637  1.0
  Li  Li1  1  0.564  0.199  0.364  1.0
  Fe  Fe2  1  0.685  0.600  0.404  1.0
  Fe  Fe3  1  0.298  0.406  0.593  1.0
  Si  Si4  1  0.467  0.758  0.927  1.0
  Si  Si5  1  0.866  0.981  0.169  1.0
  Si  Si6  1  0.081  0.865  0.419  1.0
  Si  Si7  1  0.329  0.439  0.830  1.0
  Si  Si8  1  0.767  0.559  0.169  1.0
  Si  Si9  1  0.952  0.136  0.580  1.0
  Si  Si10  1  0.850  0.019  0.830  1.0
  Si  Si11  1  0.225  0.241  0.073  1.0
  O  O12  1  0.173  0.968  0.889  1.0
  O  O13  1  0.741  0.834  0.900  1.0
  O  O14  1  0.873  0.999  0.297  1.0
  O  O15  1  0.406  0.866  0.415  1.0
  O  O16  1  0.453  0.612  0.851  1.0
  O  O17  1  0.048  0.637  0.458  1.0
  O  O18  1  0.122  0.529  0.712  1.0
  O  O19  1  0.864  0.755  0.173  1.0
  O  O20  1  0.155  0.366  0.938  1.0
  O  O21  1  0.521  0.632  0.061  1.0
  O  O22  1  0.622  0.245  0.826  1.0
  O  O23  1  0.655  0.466  0.288  1.0
  O  O24  1  0.694  0.363  0.542  1.0
  O  O25  1  0.064  0.384  0.149  1.0
  O  O26  1  0.276  0.136  0.583  1.0
  O  O27  1  0.875  0.000  0.702  1.0
  O  O28  1  0.892  0.000  0.500  1.0
  O  O29  1  0.573  0.168  0.100  1.0
  O  O30  1  0.140  0.030  0.109  1.0
[/CIF]
.
The compound described by Li2Fe2Si8O19 crystallizes in the triclinic P1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 3-coordinate geometry to one O(16), one O(17), and one O(7) atom. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(12), one O(17), and one O(3) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(12), one O(13), one O(4), and one O(6) atom to form distorted FeO4 trigonal pyramids that share  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(13), one O(15), one O(6), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(6)O4 tetrahedra, and corners with two equivalent Fe(1)O4 trigonal pyramids. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(2), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(18), one O(19), one O(3), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(17), one O(3), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and corners with two equivalent Fe(1)O4 trigonal pyramids. In the fourth Si site, Si(4) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and  a cornercorner with one Si(8)O4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(10), one O(12), one O(14), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and  a cornercorner with one Fe(1)O4 trigonal pyramid. In the sixth Si site, Si(6) is bonded to one O(13), one O(15), one O(16), and one O(17) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and  a cornercorner with one Fe(1)O4 trigonal pyramid. In the seventh Si site, Si(7) is bonded to one O(1), one O(11), one O(16), and one O(2) atom to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(14), one O(18), one O(19), and one O(9) atom to form corner-sharing SiO4 tetrahedra. There are nineteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(7) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(7) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(2), and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Fe(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one Si(4) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Si(2) and one Si(5) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(8) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Si(4) and one Si(7) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(5) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(8) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one Si(6) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(6), and one Si(7) atom. In the seventeenth O site, O(17) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Si(3), and one Si(6) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(8) atom. In the nineteenth O site, O(19) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(8) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Fe2Si8O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.947
_cell_length_b   7.189
_cell_length_c   12.505
_cell_angle_alpha   72.899
_cell_angle_beta   89.969
_cell_angle_gamma   70.197
_symmetry_Int_Tables_number   1
_cell_volume   397.506
_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
  Li  Li0  1  0.758  0.804  0.637  1.0
  Li  Li1  1  0.564  0.199  0.364  1.0
  Fe  Fe2  1  0.685  0.600  0.404  1.0
  Fe  Fe3  1  0.298  0.406  0.593  1.0
  Si  Si4  1  0.467  0.758  0.927  1.0
  Si  Si5  1  0.866  0.981  0.169  1.0
  Si  Si6  1  0.081  0.865  0.419  1.0
  Si  Si7  1  0.329  0.439  0.830  1.0
  Si  Si8  1  0.767  0.559  0.169  1.0
  Si  Si9  1  0.952  0.136  0.580  1.0
  Si  Si10  1  0.850  0.019  0.830  1.0
  Si  Si11  1  0.225  0.241  0.073  1.0
  O  O12  1  0.173  0.968  0.889  1.0
  O  O13  1  0.741  0.834  0.900  1.0
  O  O14  1  0.873  0.999  0.297  1.0
  O  O15  1  0.406  0.866  0.415  1.0
  O  O16  1  0.453  0.612  0.851  1.0
  O  O17  1  0.048  0.637  0.458  1.0
  O  O18  1  0.122  0.529  0.712  1.0
  O  O19  1  0.864  0.755  0.173  1.0
  O  O20  1  0.155  0.366  0.938  1.0
  O  O21  1  0.521  0.632  0.061  1.0
  O  O22  1  0.622  0.245  0.826  1.0
  O  O23  1  0.655  0.466  0.288  1.0
  O  O24  1  0.694  0.363  0.542  1.0
  O  O25  1  0.064  0.384  0.149  1.0
  O  O26  1  0.276  0.136  0.583  1.0
  O  O27  1  0.875  0.000  0.702  1.0
  O  O28  1  0.892  0.000  0.500  1.0
  O  O29  1  0.573  0.168  0.100  1.0
  O  O30  1  0.140  0.030  0.109  1.0
[/CIF]
.