Li2SO5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, and corners with four equivalent S(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with three equivalent S(1)O4 tetrahedra. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with three equivalent Li(2)O4 tetrahedra and corners with four equivalent Li(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Li(1) and one S(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Li(2) and one S(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Li(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one S(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Li(2) atom.
Li2SO5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, and corners with four equivalent S(1)O4 tetrahedra. The Li(1)-O(1) bond length is 1.95 Å. The Li(1)-O(4) bond length is 2.01 Å. There is one shorter (1.98 Å) and one longer (1.99 Å) Li(1)-O(3) bond length. In the second Li site, Li(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with three equivalent S(1)O4 tetrahedra. The Li(2)-O(4) bond length is 1.96 Å. The Li(2)-O(5) bond length is 2.05 Å. There is one shorter (1.95 Å) and one longer (1.96 Å) Li(2)-O(2) bond length. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with three equivalent Li(2)O4 tetrahedra and corners with four equivalent Li(1)O4 tetrahedra. The S(1)-O(1) bond length is 1.48 Å. The S(1)-O(2) bond length is 1.50 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.49 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Li(1) and one S(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Li(2) and one S(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Li(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one S(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Li(2) atom.