Li2Sr2Nb3O10 crystallizes in the orthorhombic Fmm2 space group. Li(1) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form SrO12 cuboctahedra that share corners with eight equivalent Sr(1)O12 cuboctahedra, faces with five equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Nb(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, and faces with eight equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-13°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Nb(1) atoms. In the second O site, O(1) is bonded to four equivalent Sr(1), one Nb(1), and one Nb(2) atom to form distorted OSr4Nb2 octahedra that share corners with five equivalent O(1)Sr4Nb2 octahedra,  a cornercorner with one O(3)Li4Nb trigonal bipyramid, and edges with four equivalent O(1)Sr4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. In the third O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1) and two equivalent Nb(2) atoms. In the fourth O site, O(3) is bonded to four equivalent Li(1) and one Nb(2) atom to form distorted OLi4Nb trigonal bipyramids that share  a cornercorner with one O(1)Sr4Nb2 octahedra, corners with four equivalent O(3)Li4Nb trigonal bipyramids, and edges with four equivalent O(3)Li4Nb trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°.
Li2Sr2Nb3O10 crystallizes in the orthorhombic Fmm2 space group. Li(1) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. There are two shorter (2.09 Å) and two longer (2.10 Å) Li(1)-O(3) bond lengths. Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form SrO12 cuboctahedra that share corners with eight equivalent Sr(1)O12 cuboctahedra, faces with five equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Nb(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. There are a spread of Sr(1)-O(1) bond distances ranging from 2.83-2.89 Å. All Sr(1)-O(2) bond lengths are 2.69 Å. There are two shorter (2.93 Å) and two longer (3.04 Å) Sr(1)-O(4) bond lengths. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, and faces with eight equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. Both Nb(1)-O(1) bond lengths are 2.03 Å. All Nb(1)-O(4) bond lengths are 2.02 Å. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-13°. The Nb(2)-O(1) bond length is 2.17 Å. The Nb(2)-O(3) bond length is 1.90 Å. There are two shorter (2.03 Å) and two longer (2.04 Å) Nb(2)-O(2) bond lengths. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Nb(1) atoms. In the second O site, O(1) is bonded to four equivalent Sr(1), one Nb(1), and one Nb(2) atom to form distorted OSr4Nb2 octahedra that share corners with five equivalent O(1)Sr4Nb2 octahedra,  a cornercorner with one O(3)Li4Nb trigonal bipyramid, and edges with four equivalent O(1)Sr4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. In the third O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1) and two equivalent Nb(2) atoms. In the fourth O site, O(3) is bonded to four equivalent Li(1) and one Nb(2) atom to form distorted OLi4Nb trigonal bipyramids that share  a cornercorner with one O(1)Sr4Nb2 octahedra, corners with four equivalent O(3)Li4Nb trigonal bipyramids, and edges with four equivalent O(3)Li4Nb trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°.