Li2SeO4 crystallizes in the trigonal R-3 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with four equivalent Se(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with four equivalent Se(1)O4 tetrahedra. Se(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra and corners with four equivalent Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(4) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Se(1) atom. In the second O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(2) and one Se(1) atom. In the third O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Se(1) atom. In the fourth O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Se(1) atom.
Li2SeO4 crystallizes in the trigonal R-3 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with four equivalent Se(1)O4 tetrahedra. The Li(1)-O(2) bond length is 1.92 Å. The Li(1)-O(3) bond length is 1.95 Å. There is one shorter (1.96 Å) and one longer (1.97 Å) Li(1)-O(4) bond length. In the second Li site, Li(2) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with four equivalent Se(1)O4 tetrahedra. The Li(2)-O(2) bond length is 1.93 Å. The Li(2)-O(3) bond length is 1.92 Å. There is one shorter (1.93 Å) and one longer (1.95 Å) Li(2)-O(1) bond length. Se(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra and corners with four equivalent Li(2)O4 tetrahedra. The Se(1)-O(1) bond length is 1.65 Å. The Se(1)-O(2) bond length is 1.65 Å. The Se(1)-O(3) bond length is 1.65 Å. The Se(1)-O(4) bond length is 1.65 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Se(1) atom. In the second O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(2) and one Se(1) atom. In the third O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Se(1) atom. In the fourth O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Se(1) atom.