Li2Nb(PO4)2 crystallizes in the monoclinic Pc space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 pentagonal pyramids,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one Nb(1)O6 pentagonal pyramid,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-76°. In the second Li site, Li(2) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted LiO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Nb(1)O6 pentagonal pyramids, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-76°. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form distorted NbO6 pentagonal pyramids that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-61°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 pentagonal pyramids,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one Nb(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 53-58°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 pentagonal pyramids,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-56°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Nb(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Nb(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Nb(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Nb(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Nb(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Li(2), one Nb(1), and one P(2) atom.
Li2Nb(PO4)2 crystallizes in the monoclinic Pc space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 pentagonal pyramids,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  an edgeedge with one Li(2)O6 octahedra,  an edgeedge with one Nb(1)O6 pentagonal pyramid,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-76°. The Li(1)-O(2) bond length is 2.42 Å. The Li(1)-O(3) bond length is 2.41 Å. The Li(1)-O(4) bond length is 2.15 Å. The Li(1)-O(5) bond length is 2.29 Å. The Li(1)-O(6) bond length is 1.96 Å. The Li(1)-O(7) bond length is 2.03 Å. In the second Li site, Li(2) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted LiO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Nb(1)O6 pentagonal pyramids, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-76°. The Li(2)-O(1) bond length is 2.05 Å. The Li(2)-O(4) bond length is 2.17 Å. The Li(2)-O(5) bond length is 2.45 Å. The Li(2)-O(6) bond length is 2.13 Å. The Li(2)-O(7) bond length is 2.09 Å. The Li(2)-O(8) bond length is 2.33 Å. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form distorted NbO6 pentagonal pyramids that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-61°. The Nb(1)-O(1) bond length is 2.15 Å. The Nb(1)-O(2) bond length is 2.09 Å. The Nb(1)-O(3) bond length is 2.13 Å. The Nb(1)-O(4) bond length is 2.24 Å. The Nb(1)-O(5) bond length is 2.02 Å. The Nb(1)-O(8) bond length is 2.00 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 pentagonal pyramids,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one Nb(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 53-58°. The P(1)-O(1) bond length is 1.56 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.57 Å. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 pentagonal pyramids,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-56°. The P(2)-O(5) bond length is 1.63 Å. The P(2)-O(6) bond length is 1.51 Å. The P(2)-O(7) bond length is 1.51 Å. The P(2)-O(8) bond length is 1.60 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Nb(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Nb(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Nb(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Nb(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Nb(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Li(2), one Nb(1), and one P(2) atom.