Li2NbP4O13 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted trigonal non-coplanar geometry to one O(12) and two equivalent O(13) atoms. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(10), one O(4), and one O(9) atom. Nb(1) is bonded to one O(1), one O(11), one O(3), one O(6), one O(7), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(12), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-47°. In the second P site, P(2) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. In the third P site, P(3) is bonded to one O(13), one O(2), one O(3), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. In the fourth P site, P(4) is bonded to one O(11), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Nb(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one P(3) and one P(4) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Nb(1) and one P(3) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Li(2) and one P(4) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one P(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Li(2), one Nb(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Li(2) and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Li(1) and one P(1) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to two equivalent Li(1) and one P(3) atom.
Li2NbP4O13 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted trigonal non-coplanar geometry to one O(12) and two equivalent O(13) atoms. The Li(1)-O(12) bond length is 1.89 Å. Both Li(1)-O(13) bond lengths are 1.98 Å. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(10), one O(4), and one O(9) atom. The Li(2)-O(10) bond length is 1.88 Å. The Li(2)-O(4) bond length is 1.96 Å. The Li(2)-O(9) bond length is 2.42 Å. Nb(1) is bonded to one O(1), one O(11), one O(3), one O(6), one O(7), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. The Nb(1)-O(1) bond length is 2.12 Å. The Nb(1)-O(11) bond length is 2.07 Å. The Nb(1)-O(3) bond length is 2.11 Å. The Nb(1)-O(6) bond length is 2.00 Å. The Nb(1)-O(7) bond length is 2.06 Å. The Nb(1)-O(9) bond length is 2.13 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(12), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-47°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(12) bond length is 1.49 Å. The P(1)-O(5) bond length is 1.65 Å. The P(1)-O(6) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. The P(2)-O(10) bond length is 1.48 Å. The P(2)-O(5) bond length is 1.59 Å. The P(2)-O(8) bond length is 1.62 Å. The P(2)-O(9) bond length is 1.54 Å. In the third P site, P(3) is bonded to one O(13), one O(2), one O(3), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. The P(3)-O(13) bond length is 1.50 Å. The P(3)-O(2) bond length is 1.59 Å. The P(3)-O(3) bond length is 1.53 Å. The P(3)-O(8) bond length is 1.60 Å. In the fourth P site, P(4) is bonded to one O(11), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. The P(4)-O(11) bond length is 1.55 Å. The P(4)-O(2) bond length is 1.64 Å. The P(4)-O(4) bond length is 1.49 Å. The P(4)-O(7) bond length is 1.56 Å. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Nb(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one P(3) and one P(4) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Nb(1) and one P(3) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Li(2) and one P(4) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one P(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Li(2), one Nb(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Li(2) and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Li(1) and one P(1) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to two equivalent Li(1) and one P(3) atom.