Li6Sr3Nb2O11 crystallizes in the orthorhombic Pmma space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(2)O5 trigonal bipyramids, corners with two equivalent Nb(1)O5 trigonal bipyramids,  an edgeedge with one Nb(2)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(5), two equivalent O(1), and two equivalent O(4) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra,  a cornercorner with one Nb(1)O5 trigonal bipyramid, edges with two equivalent Nb(2)O6 octahedra,  an edgeedge with one Li(3)O4 tetrahedra, and  an edgeedge with one Li(2)O5 trigonal bipyramid. In the third Li site, Li(3) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Nb(2)O6 octahedra,  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O5 trigonal bipyramid, corners with two equivalent Nb(1)O5 trigonal bipyramids, and  an edgeedge with one Li(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 14°. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), and four equivalent O(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(5) atoms to form NbO5 trigonal bipyramids that share corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. In the second Nb site, Nb(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form NbO6 octahedra that share corners with four equivalent Li(3)O4 tetrahedra, edges with two equivalent Li(1)O4 tetrahedra, and edges with four equivalent Li(2)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Li(1), two equivalent Sr(1), and one Nb(1) atom. In the second O site, O(4) is bonded to two equivalent Li(2), one Sr(2), two equivalent Sr(1), and one Nb(2) atom to form distorted OSr3Li2Nb octahedra that share  a cornercorner with one O(4)Sr3Li2Nb octahedra, corners with four equivalent O(1)Sr2Li3Nb octahedra,  an edgeedge with one O(4)Sr3Li2Nb octahedra, edges with six equivalent O(1)Sr2Li3Nb octahedra, and  a faceface with one O(4)Sr3Li2Nb octahedra. The corner-sharing octahedral tilt angles range from 0-36°. In the third O site, O(5) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), one Sr(2), two equivalent Sr(1), and one Nb(1) atom. In the fourth O site, O(1) is bonded to one Li(1), one Li(2), one Li(3), one Sr(1), one Sr(2), and one Nb(2) atom to form distorted OSr2Li3Nb octahedra that share corners with two equivalent O(4)Sr3Li2Nb octahedra, corners with three equivalent O(1)Sr2Li3Nb octahedra, edges with two equivalent O(1)Sr2Li3Nb octahedra, edges with three equivalent O(4)Sr3Li2Nb octahedra, and  a faceface with one O(1)Sr2Li3Nb octahedra. The corner-sharing octahedral tilt angles range from 0-70°. In the fifth O site, O(2) is bonded in a trigonal planar geometry to two equivalent Li(3) and one Nb(1) atom.
Li6Sr3Nb2O11 crystallizes in the orthorhombic Pmma space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(2)O5 trigonal bipyramids, corners with two equivalent Nb(1)O5 trigonal bipyramids,  an edgeedge with one Nb(2)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. Both Li(1)-O(1) bond lengths are 2.06 Å. Both Li(1)-O(3) bond lengths are 2.00 Å. In the second Li site, Li(2) is bonded to one O(5), two equivalent O(1), and two equivalent O(4) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra,  a cornercorner with one Nb(1)O5 trigonal bipyramid, edges with two equivalent Nb(2)O6 octahedra,  an edgeedge with one Li(3)O4 tetrahedra, and  an edgeedge with one Li(2)O5 trigonal bipyramid. The Li(2)-O(5) bond length is 2.08 Å. Both Li(2)-O(1) bond lengths are 2.21 Å. Both Li(2)-O(4) bond lengths are 2.09 Å. In the third Li site, Li(3) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Nb(2)O6 octahedra,  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra,  a cornercorner with one Li(2)O5 trigonal bipyramid, corners with two equivalent Nb(1)O5 trigonal bipyramids, and  an edgeedge with one Li(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 14°. The Li(3)-O(2) bond length is 1.80 Å. The Li(3)-O(5) bond length is 2.04 Å. Both Li(3)-O(1) bond lengths are 1.94 Å. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Both Sr(1)-O(1) bond lengths are 2.56 Å. Both Sr(1)-O(3) bond lengths are 2.53 Å. Both Sr(1)-O(4) bond lengths are 2.78 Å. Both Sr(1)-O(5) bond lengths are 2.69 Å. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), and four equivalent O(1) atoms. Both Sr(2)-O(4) bond lengths are 2.47 Å. Both Sr(2)-O(5) bond lengths are 2.73 Å. All Sr(2)-O(1) bond lengths are 2.54 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(5) atoms to form NbO5 trigonal bipyramids that share corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. The Nb(1)-O(2) bond length is 1.87 Å. Both Nb(1)-O(3) bond lengths are 2.02 Å. Both Nb(1)-O(5) bond lengths are 1.94 Å. In the second Nb site, Nb(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form NbO6 octahedra that share corners with four equivalent Li(3)O4 tetrahedra, edges with two equivalent Li(1)O4 tetrahedra, and edges with four equivalent Li(2)O5 trigonal bipyramids. Both Nb(2)-O(4) bond lengths are 2.01 Å. All Nb(2)-O(1) bond lengths are 2.03 Å. There are five inequivalent O sites. In the first O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Li(1), two equivalent Sr(1), and one Nb(1) atom. In the second O site, O(4) is bonded to two equivalent Li(2), one Sr(2), two equivalent Sr(1), and one Nb(2) atom to form distorted OSr3Li2Nb octahedra that share  a cornercorner with one O(4)Sr3Li2Nb octahedra, corners with four equivalent O(1)Sr2Li3Nb octahedra,  an edgeedge with one O(4)Sr3Li2Nb octahedra, edges with six equivalent O(1)Sr2Li3Nb octahedra, and  a faceface with one O(4)Sr3Li2Nb octahedra. The corner-sharing octahedral tilt angles range from 0-36°. In the third O site, O(5) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), one Sr(2), two equivalent Sr(1), and one Nb(1) atom. In the fourth O site, O(1) is bonded to one Li(1), one Li(2), one Li(3), one Sr(1), one Sr(2), and one Nb(2) atom to form distorted OSr2Li3Nb octahedra that share corners with two equivalent O(4)Sr3Li2Nb octahedra, corners with three equivalent O(1)Sr2Li3Nb octahedra, edges with two equivalent O(1)Sr2Li3Nb octahedra, edges with three equivalent O(4)Sr3Li2Nb octahedra, and  a faceface with one O(1)Sr2Li3Nb octahedra. The corner-sharing octahedral tilt angles range from 0-70°. In the fifth O site, O(2) is bonded in a trigonal planar geometry to two equivalent Li(3) and one Nb(1) atom.