Li2Fe4Si4O13 is Esseneite-like structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 71-88°. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), and one O(9) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with three equivalent Fe(2)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  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,  an edgeedge with one Fe(2)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the third Fe site, Fe(3) is bonded to one O(10), one O(3), one O(7), one O(9), and two equivalent O(8) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra, edges with three equivalent Fe(4)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(4), one O(8), one O(9), and two equivalent O(7) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Fe(4)O6 octahedra, edges with three equivalent Fe(3)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are four 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(9) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with three equivalent Li(1)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-59°. In the second Si site, Si(2) is bonded to one O(10), one O(12), one O(13), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-63°. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-72°. In the fourth Si site, Si(4) is bonded to one O(1), one O(11), one O(13), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-75°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Fe(2), two equivalent Fe(1), and one Si(4) atom to form distorted OFe3Si tetrahedra that share  a cornercorner with one O(7)Fe3Si tetrahedra, corners with three equivalent O(5)LiFe2Si tetrahedra,  a cornercorner with one O(2)LiFe2Si trigonal pyramid, corners with two equivalent O(4)LiFe2Si trigonal pyramids,  an edgeedge with one O(1)Fe3Si tetrahedra, and  an edgeedge with one O(2)LiFe2Si trigonal pyramid. In the second O site, O(2) is bonded to one Li(1), one Fe(1), one Fe(2), and one Si(1) atom to form distorted OLiFe2Si trigonal pyramids that share  a cornercorner with one O(1)Fe3Si tetrahedra, corners with three equivalent O(5)LiFe2Si tetrahedra,  a cornercorner with one O(4)LiFe2Si trigonal pyramid,  an edgeedge with one O(1)Fe3Si tetrahedra, and  an edgeedge with one O(4)LiFe2Si trigonal pyramid. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Li(1), one Fe(2), one Fe(3), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Li(1), one Fe(1), one Fe(4), and one Si(1) atom to form distorted OLiFe2Si trigonal pyramids that share corners with two equivalent O(1)Fe3Si tetrahedra, corners with two equivalent O(7)Fe3Si tetrahedra, corners with two equivalent O(5)LiFe2Si tetrahedra,  a cornercorner with one O(2)LiFe2Si trigonal pyramid, and  an edgeedge with one O(2)LiFe2Si trigonal pyramid. In the fifth O site, O(5) is bonded to one Li(1), one Fe(1), one Fe(2), and one Si(2) atom to form distorted OLiFe2Si tetrahedra that share corners with three equivalent O(1)Fe3Si tetrahedra, corners with two equivalent O(4)LiFe2Si trigonal pyramids, and corners with three equivalent O(2)LiFe2Si trigonal pyramids. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one Si(3) atom. In the seventh O site, O(7) is bonded to one Fe(3), two equivalent Fe(4), and one Si(4) atom to form distorted OFe3Si tetrahedra that share  a cornercorner with one O(1)Fe3Si tetrahedra, corners with two equivalent O(4)LiFe2Si trigonal pyramids, and  an edgeedge with one O(7)Fe3Si tetrahedra. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Fe(4), two equivalent Fe(3), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Fe(3), one Fe(4), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Li(2), one Fe(3), one Fe(4), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(3), and one Si(4) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Li(2), one Si(2), and one Si(3) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Si(2) and one Si(4) atom.
Li2Fe4Si4O13 is Esseneite-like structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 71-88°. The Li(1)-O(2) bond length is 2.03 Å. The Li(1)-O(3) bond length is 2.12 Å. The Li(1)-O(4) bond length is 2.15 Å. The Li(1)-O(5) bond length is 1.97 Å. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), and one O(9) atom. The Li(2)-O(10) bond length is 2.12 Å. The Li(2)-O(11) bond length is 1.96 Å. The Li(2)-O(12) bond length is 2.10 Å. The Li(2)-O(9) bond length is 1.91 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with three equivalent Fe(2)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. The Fe(1)-O(2) bond length is 2.22 Å. The Fe(1)-O(4) bond length is 2.09 Å. The Fe(1)-O(5) bond length is 2.18 Å. The Fe(1)-O(6) bond length is 2.41 Å. There is one shorter (2.21 Å) and one longer (2.34 Å) Fe(1)-O(1) bond length. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  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,  an edgeedge with one Fe(2)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Fe(2)-O(1) bond length is 2.27 Å. The Fe(2)-O(2) bond length is 2.15 Å. The Fe(2)-O(3) bond length is 2.20 Å. The Fe(2)-O(5) bond length is 2.29 Å. There is one shorter (2.14 Å) and one longer (2.25 Å) Fe(2)-O(6) bond length. In the third Fe site, Fe(3) is bonded to one O(10), one O(3), one O(7), one O(9), and two equivalent O(8) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra, edges with three equivalent Fe(4)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Fe(3)-O(10) bond length is 2.21 Å. The Fe(3)-O(3) bond length is 2.18 Å. The Fe(3)-O(7) bond length is 2.21 Å. The Fe(3)-O(9) bond length is 2.36 Å. There is one shorter (2.12 Å) and one longer (2.25 Å) Fe(3)-O(8) bond length. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(4), one O(8), one O(9), and two equivalent O(7) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  an edgeedge with one Fe(4)O6 octahedra, edges with three equivalent Fe(3)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. The Fe(4)-O(10) bond length is 2.34 Å. The Fe(4)-O(4) bond length is 2.30 Å. The Fe(4)-O(8) bond length is 2.45 Å. The Fe(4)-O(9) bond length is 2.08 Å. There is one shorter (2.16 Å) and one longer (2.34 Å) Fe(4)-O(7) bond length. There are four 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(9) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with three equivalent Li(1)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-59°. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.67 Å. The Si(1)-O(9) bond length is 1.67 Å. In the second Si site, Si(2) is bonded to one O(10), one O(12), one O(13), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-63°. The Si(2)-O(10) bond length is 1.64 Å. The Si(2)-O(12) bond length is 1.65 Å. The Si(2)-O(13) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.62 Å. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-72°. The Si(3)-O(11) bond length is 1.63 Å. The Si(3)-O(12) bond length is 1.67 Å. The Si(3)-O(6) bond length is 1.61 Å. The Si(3)-O(8) bond length is 1.62 Å. In the fourth Si site, Si(4) is bonded to one O(1), one O(11), one O(13), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-75°. The Si(4)-O(1) bond length is 1.62 Å. The Si(4)-O(11) bond length is 1.62 Å. The Si(4)-O(13) bond length is 1.65 Å. The Si(4)-O(7) bond length is 1.64 Å. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Fe(2), two equivalent Fe(1), and one Si(4) atom to form distorted OFe3Si tetrahedra that share  a cornercorner with one O(7)Fe3Si tetrahedra, corners with three equivalent O(5)LiFe2Si tetrahedra,  a cornercorner with one O(2)LiFe2Si trigonal pyramid, corners with two equivalent O(4)LiFe2Si trigonal pyramids,  an edgeedge with one O(1)Fe3Si tetrahedra, and  an edgeedge with one O(2)LiFe2Si trigonal pyramid. In the second O site, O(2) is bonded to one Li(1), one Fe(1), one Fe(2), and one Si(1) atom to form distorted OLiFe2Si trigonal pyramids that share  a cornercorner with one O(1)Fe3Si tetrahedra, corners with three equivalent O(5)LiFe2Si tetrahedra,  a cornercorner with one O(4)LiFe2Si trigonal pyramid,  an edgeedge with one O(1)Fe3Si tetrahedra, and  an edgeedge with one O(4)LiFe2Si trigonal pyramid. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Li(1), one Fe(2), one Fe(3), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Li(1), one Fe(1), one Fe(4), and one Si(1) atom to form distorted OLiFe2Si trigonal pyramids that share corners with two equivalent O(1)Fe3Si tetrahedra, corners with two equivalent O(7)Fe3Si tetrahedra, corners with two equivalent O(5)LiFe2Si tetrahedra,  a cornercorner with one O(2)LiFe2Si trigonal pyramid, and  an edgeedge with one O(2)LiFe2Si trigonal pyramid. In the fifth O site, O(5) is bonded to one Li(1), one Fe(1), one Fe(2), and one Si(2) atom to form distorted OLiFe2Si tetrahedra that share corners with three equivalent O(1)Fe3Si tetrahedra, corners with two equivalent O(4)LiFe2Si trigonal pyramids, and corners with three equivalent O(2)LiFe2Si trigonal pyramids. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Fe(1), two equivalent Fe(2), and one Si(3) atom. In the seventh O site, O(7) is bonded to one Fe(3), two equivalent Fe(4), and one Si(4) atom to form distorted OFe3Si tetrahedra that share  a cornercorner with one O(1)Fe3Si tetrahedra, corners with two equivalent O(4)LiFe2Si trigonal pyramids, and  an edgeedge with one O(7)Fe3Si tetrahedra. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Fe(4), two equivalent Fe(3), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Fe(3), one Fe(4), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Li(2), one Fe(3), one Fe(4), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(3), and one Si(4) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Li(2), one Si(2), and one Si(3) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Si(2) and one Si(4) atom.