Li2Fe2Si5O13 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 3-coordinate geometry to one O(1), one O(10), one O(12), and one O(13) atom. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(1), one O(10), one O(5), and one O(8) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(12), one O(7), one O(8), and two equivalent O(2) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(10), one O(12), one O(2), one O(7), and one O(8) atom. There are five inequivalent Si sites. In the first Si site, 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 two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-70°. In the second Si site, Si(2) is bonded to one O(1), one O(11), one O(13), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the third Si site, Si(3) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-63°. In the fourth Si site, Si(4) is bonded to one O(12), one O(13), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. In the fifth Si site, Si(5) is bonded to one O(10), one O(11), one O(3), and one O(6) atom to form corner-sharing SiO4 tetrahedra. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one Si(2) atom. In the second O site, O(2) is bonded to one Fe(2), two equivalent Fe(1), and one Si(1) atom to form distorted OFe3Si tetrahedra that share  a cornercorner with one O(10)Li2FeSi trigonal pyramid and  an edgeedge with one O(2)Fe3Si tetrahedra. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(5) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(1), and one Si(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(5) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Li(2), one Fe(1), one Fe(2), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the tenth O site, O(10) is bonded to one Li(1), one Li(2), one Fe(2), and one Si(5) atom to form distorted corner-sharing OLi2FeSi trigonal pyramids. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Si(2) and one Si(5) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Fe(2), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(2), and one Si(4) atom.
Li2Fe2Si5O13 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 3-coordinate geometry to one O(1), one O(10), one O(12), and one O(13) atom. The Li(1)-O(1) bond length is 1.87 Å. The Li(1)-O(10) bond length is 1.85 Å. The Li(1)-O(12) bond length is 2.55 Å. The Li(1)-O(13) bond length is 1.88 Å. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(1), one O(10), one O(5), and one O(8) atom. The Li(2)-O(1) bond length is 2.09 Å. The Li(2)-O(10) bond length is 2.09 Å. The Li(2)-O(5) bond length is 2.10 Å. The Li(2)-O(8) bond length is 1.89 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(12), one O(7), one O(8), and two equivalent O(2) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The Fe(1)-O(1) bond length is 2.12 Å. The Fe(1)-O(12) bond length is 2.33 Å. The Fe(1)-O(7) bond length is 2.15 Å. The Fe(1)-O(8) bond length is 2.43 Å. There is one shorter (2.16 Å) and one longer (2.38 Å) Fe(1)-O(2) bond length. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(10), one O(12), one O(2), one O(7), and one O(8) atom. The Fe(2)-O(10) bond length is 2.05 Å. The Fe(2)-O(12) bond length is 2.12 Å. The Fe(2)-O(2) bond length is 2.37 Å. The Fe(2)-O(7) bond length is 2.17 Å. The Fe(2)-O(8) bond length is 2.35 Å. There are five inequivalent Si sites. In the first Si site, 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 two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-70°. The Si(1)-O(2) bond length is 1.63 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.63 Å. The Si(1)-O(5) bond length is 1.66 Å. In the second Si site, Si(2) is bonded to one O(1), one O(11), one O(13), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. The Si(2)-O(1) bond length is 1.61 Å. The Si(2)-O(11) bond length is 1.64 Å. The Si(2)-O(13) bond length is 1.68 Å. The Si(2)-O(6) bond length is 1.60 Å. In the third Si site, Si(3) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-63°. The Si(3)-O(4) bond length is 1.66 Å. The Si(3)-O(7) bond length is 1.63 Å. The Si(3)-O(8) bond length is 1.63 Å. The Si(3)-O(9) bond length is 1.67 Å. In the fourth Si site, Si(4) is bonded to one O(12), one O(13), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. The Si(4)-O(12) bond length is 1.62 Å. The Si(4)-O(13) bond length is 1.68 Å. The Si(4)-O(5) bond length is 1.64 Å. The Si(4)-O(9) bond length is 1.62 Å. In the fifth Si site, Si(5) is bonded to one O(10), one O(11), one O(3), and one O(6) atom to form corner-sharing SiO4 tetrahedra. The Si(5)-O(10) bond length is 1.61 Å. The Si(5)-O(11) bond length is 1.65 Å. The Si(5)-O(3) bond length is 1.66 Å. The Si(5)-O(6) bond length is 1.61 Å. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one Si(2) atom. In the second O site, O(2) is bonded to one Fe(2), two equivalent Fe(1), and one Si(1) atom to form distorted OFe3Si tetrahedra that share  a cornercorner with one O(10)Li2FeSi trigonal pyramid and  an edgeedge with one O(2)Fe3Si tetrahedra. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(5) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(1), and one Si(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(5) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Li(2), one Fe(1), one Fe(2), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the tenth O site, O(10) is bonded to one Li(1), one Li(2), one Fe(2), and one Si(5) atom to form distorted corner-sharing OLi2FeSi trigonal pyramids. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Si(2) and one Si(5) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Fe(2), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(2), and one Si(4) atom.