Li5NbO5 crystallizes in the monoclinic C2/m space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form distorted LiO5 square pyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Li(1)O5 square pyramids, corners with two equivalent Li(2)O5 trigonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, edges with two equivalent Li(1)O5 square pyramids, and edges with three equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-10°. In the second Li site, Li(2) is bonded to one O(2), one O(3), and three equivalent O(1) atoms to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Li(1)O5 square pyramids, corners with three equivalent Li(2)O5 trigonal bipyramids, edges with three equivalent Nb(1)O6 octahedra, edges with three equivalent Li(1)O5 square pyramids, and edges with two equivalent Li(2)O5 trigonal bipyramids. In the third Li site, Li(3) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Li(1)O5 square pyramids, edges with four equivalent Li(1)O5 square pyramids, and edges with six equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), three equivalent Li(2), and one Nb(1) atom to form OLi5Nb octahedra that share corners with four equivalent O(1)Li5Nb octahedra, edges with two equivalent O(1)Li5Nb octahedra, edges with three equivalent O(3)Li4Nb2 octahedra, and edges with five equivalent O(2)Li5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-25°. In the second O site, O(2) is bonded to one Li(2), one Li(3), three equivalent Li(1), and one Nb(1) atom to form OLi5Nb octahedra that share corners with two equivalent O(3)Li4Nb2 octahedra, corners with four equivalent O(2)Li5Nb octahedra, edges with two equivalent O(3)Li4Nb2 octahedra, edges with two equivalent O(2)Li5Nb octahedra, and edges with five equivalent O(1)Li5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-28°. In the third O site, O(3) is bonded to two equivalent Li(1), two equivalent Li(2), and two equivalent Nb(1) atoms to form OLi4Nb2 octahedra that share corners with two equivalent O(3)Li4Nb2 octahedra, corners with four equivalent O(2)Li5Nb octahedra, edges with four equivalent O(2)Li5Nb octahedra, and edges with six equivalent O(1)Li5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-19°.
Li5NbO5 crystallizes in the monoclinic C2/m space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form distorted LiO5 square pyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Li(1)O5 square pyramids, corners with two equivalent Li(2)O5 trigonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, edges with two equivalent Li(1)O5 square pyramids, and edges with three equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-10°. The Li(1)-O(1) bond length is 1.96 Å. The Li(1)-O(3) bond length is 2.40 Å. There is one shorter (1.99 Å) and two longer (2.10 Å) Li(1)-O(2) bond lengths. In the second Li site, Li(2) is bonded to one O(2), one O(3), and three equivalent O(1) atoms to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Li(1)O5 square pyramids, corners with three equivalent Li(2)O5 trigonal bipyramids, edges with three equivalent Nb(1)O6 octahedra, edges with three equivalent Li(1)O5 square pyramids, and edges with two equivalent Li(2)O5 trigonal bipyramids. The Li(2)-O(2) bond length is 2.07 Å. The Li(2)-O(3) bond length is 2.30 Å. There is one shorter (2.02 Å) and two longer (2.08 Å) Li(2)-O(1) bond lengths. In the third Li site, Li(3) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Li(3)-O(1) bond lengths are 1.98 Å. Both Li(3)-O(2) bond lengths are 2.16 Å. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Li(1)O5 square pyramids, edges with four equivalent Li(1)O5 square pyramids, and edges with six equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedra are not tilted. Both Nb(1)-O(1) bond lengths are 2.01 Å. Both Nb(1)-O(2) bond lengths are 2.01 Å. Both Nb(1)-O(3) bond lengths are 2.03 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), three equivalent Li(2), and one Nb(1) atom to form OLi5Nb octahedra that share corners with four equivalent O(1)Li5Nb octahedra, edges with two equivalent O(1)Li5Nb octahedra, edges with three equivalent O(3)Li4Nb2 octahedra, and edges with five equivalent O(2)Li5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-25°. In the second O site, O(2) is bonded to one Li(2), one Li(3), three equivalent Li(1), and one Nb(1) atom to form OLi5Nb octahedra that share corners with two equivalent O(3)Li4Nb2 octahedra, corners with four equivalent O(2)Li5Nb octahedra, edges with two equivalent O(3)Li4Nb2 octahedra, edges with two equivalent O(2)Li5Nb octahedra, and edges with five equivalent O(1)Li5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-28°. In the third O site, O(3) is bonded to two equivalent Li(1), two equivalent Li(2), and two equivalent Nb(1) atoms to form OLi4Nb2 octahedra that share corners with two equivalent O(3)Li4Nb2 octahedra, corners with four equivalent O(2)Li5Nb octahedra, edges with four equivalent O(2)Li5Nb octahedra, and edges with six equivalent O(1)Li5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-19°.