LiFeSi3O8 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(5), one O(7), and one O(8) atom. Fe(1) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Fe(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate 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 trigonal non-coplanar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(2), and one Si(3) atom.
LiFeSi3O8 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(5), one O(7), and one O(8) atom. The Li(1)-O(4) bond length is 2.25 Å. The Li(1)-O(5) bond length is 2.06 Å. The Li(1)-O(7) bond length is 2.24 Å. The Li(1)-O(8) bond length is 2.18 Å. Fe(1) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.85 Å. The Fe(1)-O(4) bond length is 1.90 Å. The Fe(1)-O(5) bond length is 1.92 Å. The Fe(1)-O(7) bond length is 1.90 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. The Si(1)-O(2) bond length is 1.63 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(5) bond length is 1.62 Å. The Si(1)-O(6) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Fe(1)O4 tetrahedra. The Si(2)-O(1) bond length is 1.61 Å. The Si(2)-O(4) bond length is 1.63 Å. The Si(2)-O(6) bond length is 1.64 Å. The Si(2)-O(8) bond length is 1.68 Å. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The Si(3)-O(2) bond length is 1.63 Å. The Si(3)-O(3) bond length is 1.63 Å. The Si(3)-O(7) bond length is 1.62 Å. The Si(3)-O(8) bond length is 1.66 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate 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 trigonal non-coplanar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(2), and one Si(3) atom.