LiNb3(Bi2O7)2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(6) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(7) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. In the second Nb site, Nb(2) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), one O(6), one O(7), and two equivalent O(2) atoms. In the second Bi site, Bi(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Nb(2), one Bi(1), and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to one Li(1), one Bi(2), and two equivalent Bi(1) atoms to form distorted OLiBi3 tetrahedra that share  a cornercorner with one O(2)LiBi3 tetrahedra, corners with two equivalent O(4)NbBi3 tetrahedra,  an edgeedge with one O(2)LiBi3 tetrahedra, and  an edgeedge with one O(4)NbBi3 tetrahedra. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Nb(1), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded to one Nb(1), one Bi(1), and two equivalent Bi(2) atoms to form distorted ONbBi3 tetrahedra that share corners with two equivalent O(2)LiBi3 tetrahedra,  an edgeedge with one O(2)LiBi3 tetrahedra, and  an edgeedge with one O(4)NbBi3 tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(1), one Nb(1), one Nb(2), and one Bi(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Bi(1) atom.
LiNb3(Bi2O7)2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(6) atoms. Both Li(1)-O(2) bond lengths are 2.00 Å. Both Li(1)-O(6) bond lengths are 2.09 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(7) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. The Nb(1)-O(3) bond length is 1.93 Å. The Nb(1)-O(4) bond length is 2.10 Å. The Nb(1)-O(5) bond length is 2.11 Å. The Nb(1)-O(6) bond length is 1.96 Å. There is one shorter (1.90 Å) and one longer (2.23 Å) Nb(1)-O(7) bond length. In the second Nb site, Nb(2) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. Both Nb(2)-O(1) bond lengths are 2.03 Å. Both Nb(2)-O(5) bond lengths are 1.93 Å. Both Nb(2)-O(6) bond lengths are 2.12 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), one O(6), one O(7), and two equivalent O(2) atoms. The Bi(1)-O(1) bond length is 2.54 Å. The Bi(1)-O(3) bond length is 2.80 Å. The Bi(1)-O(4) bond length is 2.42 Å. The Bi(1)-O(6) bond length is 2.76 Å. The Bi(1)-O(7) bond length is 2.63 Å. Both Bi(1)-O(2) bond lengths are 2.23 Å. In the second Bi site, Bi(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms. The Bi(2)-O(2) bond length is 2.47 Å. The Bi(2)-O(3) bond length is 2.25 Å. The Bi(2)-O(5) bond length is 2.64 Å. There is one shorter (2.27 Å) and one longer (2.70 Å) Bi(2)-O(1) bond length. There is one shorter (2.29 Å) and one longer (2.65 Å) Bi(2)-O(4) bond length. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Nb(2), one Bi(1), and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to one Li(1), one Bi(2), and two equivalent Bi(1) atoms to form distorted OLiBi3 tetrahedra that share  a cornercorner with one O(2)LiBi3 tetrahedra, corners with two equivalent O(4)NbBi3 tetrahedra,  an edgeedge with one O(2)LiBi3 tetrahedra, and  an edgeedge with one O(4)NbBi3 tetrahedra. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Nb(1), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded to one Nb(1), one Bi(1), and two equivalent Bi(2) atoms to form distorted ONbBi3 tetrahedra that share corners with two equivalent O(2)LiBi3 tetrahedra,  an edgeedge with one O(2)LiBi3 tetrahedra, and  an edgeedge with one O(4)NbBi3 tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(1), one Nb(1), one Nb(2), and one Bi(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Bi(1) atom.