LiFeSi3O8 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), one O(5), and one O(8) atom. Fe(1) is bonded to one O(1), one O(4), one O(6), one O(8), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Si(2)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-37°. In the second Si site, Si(2) is bonded to one O(2), one O(4), 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 Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-62°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the third O site, O(3) is bonded in a linear geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), two equivalent Fe(1), and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(1), one Si(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Fe(1), and one Si(2) atom.
LiFeSi3O8 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), one O(5), and one O(8) atom. The Li(1)-O(1) bond length is 2.00 Å. The Li(1)-O(4) bond length is 2.02 Å. The Li(1)-O(5) bond length is 2.10 Å. The Li(1)-O(8) bond length is 2.32 Å. Fe(1) is bonded to one O(1), one O(4), one O(6), one O(8), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Si(2)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.93 Å. The Fe(1)-O(4) bond length is 1.97 Å. The Fe(1)-O(6) bond length is 2.35 Å. The Fe(1)-O(8) bond length is 2.03 Å. There is one shorter (2.03 Å) and one longer (2.38 Å) Fe(1)-O(5) bond length. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-37°. The Si(1)-O(1) bond length is 1.61 Å. The Si(1)-O(3) bond length is 1.62 Å. The Si(1)-O(6) bond length is 1.66 Å. The Si(1)-O(7) bond length is 1.62 Å. In the second Si site, Si(2) is bonded to one O(2), one O(4), 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 Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. The Si(2)-O(2) bond length is 1.64 Å. The Si(2)-O(4) bond length is 1.62 Å. The Si(2)-O(6) bond length is 1.68 Å. The Si(2)-O(8) bond length is 1.63 Å. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-62°. The Si(3)-O(2) bond length is 1.62 Å. The Si(3)-O(3) bond length is 1.62 Å. The Si(3)-O(5) bond length is 1.64 Å. The Si(3)-O(7) bond length is 1.63 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the third O site, O(3) is bonded in a linear geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), two equivalent Fe(1), and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(1), one Si(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Fe(1), and one Si(2) atom.