Li3Nb6O11 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to six equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Li(2)O4 tetrahedra and edges with six equivalent Nb(1)O5 square pyramids. In the second Li site, Li(2) is bonded to one O(3) and three equivalent O(1) atoms to form LiO4 tetrahedra that share corners with three equivalent Li(1)O6 octahedra and corners with nine equivalent Nb(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 64°. Nb(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form NbO5 square pyramids that share corners with six equivalent Nb(1)O5 square pyramids, corners with three equivalent Li(2)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and edges with two equivalent Nb(1)O5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a square co-planar geometry to four equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to one Li(2) and three equivalent Nb(1) atoms.
Li3Nb6O11 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to six equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Li(2)O4 tetrahedra and edges with six equivalent Nb(1)O5 square pyramids. All Li(1)-O(1) bond lengths are 2.18 Å. In the second Li site, Li(2) is bonded to one O(3) and three equivalent O(1) atoms to form LiO4 tetrahedra that share corners with three equivalent Li(1)O6 octahedra and corners with nine equivalent Nb(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 64°. The Li(2)-O(3) bond length is 1.98 Å. All Li(2)-O(1) bond lengths are 2.00 Å. Nb(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form NbO5 square pyramids that share corners with six equivalent Nb(1)O5 square pyramids, corners with three equivalent Li(2)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and edges with two equivalent Nb(1)O5 square pyramids. The Nb(1)-O(3) bond length is 2.16 Å. Both Nb(1)-O(1) bond lengths are 2.02 Å. Both Nb(1)-O(2) bond lengths are 2.18 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a square co-planar geometry to four equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to one Li(2) and three equivalent Nb(1) atoms.