LiNbPO5 crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form LiO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and faces with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-68°. In the second Li site, Li(2) is bonded to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom to form LiO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a faceface with one Nb(1)O6 octahedra, and  a faceface with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-68°. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-55°. In the second Nb site, Nb(2) is bonded to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and faces with two equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. In the third Nb site, Nb(3) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(9) atoms to form NbO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent P(2)O4 tetrahedra, and faces with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. 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(5) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-43°. In the second P site, P(2) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-45°. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a 3-coordinate geometry to one Li(2), one Nb(3), and one P(2) atom. In the second O site, O(10) is bonded in a 3-coordinate geometry to one Li(2), one Nb(3), and one P(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one Nb(1), and one P(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Nb(2), and one Nb(3) atom. In the seventh O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Nb(1), and one P(1) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Nb(1), and one Nb(2) atom. In the ninth O site, O(7) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(2) atom. In the tenth O site, O(8) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(2) atom.
LiNbPO5 crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form LiO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and faces with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-68°. The Li(1)-O(1) bond length is 2.10 Å. The Li(1)-O(2) bond length is 2.18 Å. The Li(1)-O(4) bond length is 2.23 Å. The Li(1)-O(6) bond length is 2.31 Å. The Li(1)-O(7) bond length is 2.07 Å. The Li(1)-O(8) bond length is 2.19 Å. In the second Li site, Li(2) is bonded to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom to form LiO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  a faceface with one Nb(1)O6 octahedra, and  a faceface with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-68°. The Li(2)-O(10) bond length is 2.14 Å. The Li(2)-O(3) bond length is 2.14 Å. The Li(2)-O(4) bond length is 2.32 Å. The Li(2)-O(5) bond length is 2.10 Å. The Li(2)-O(6) bond length is 2.31 Å. The Li(2)-O(9) bond length is 2.15 Å. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-55°. Both Nb(1)-O(3) bond lengths are 2.08 Å. Both Nb(1)-O(5) bond lengths are 2.13 Å. Both Nb(1)-O(6) bond lengths are 1.97 Å. In the second Nb site, Nb(2) is bonded to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and faces with two equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. The Nb(2)-O(1) bond length is 2.10 Å. The Nb(2)-O(2) bond length is 2.13 Å. The Nb(2)-O(4) bond length is 2.01 Å. The Nb(2)-O(6) bond length is 1.99 Å. The Nb(2)-O(7) bond length is 2.11 Å. The Nb(2)-O(8) bond length is 2.12 Å. In the third Nb site, Nb(3) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(9) atoms to form NbO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent P(2)O4 tetrahedra, and faces with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. Both Nb(3)-O(10) bond lengths are 2.14 Å. Both Nb(3)-O(4) bond lengths are 2.00 Å. Both Nb(3)-O(9) bond lengths are 2.08 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(5) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-43°. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(5) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-45°. The P(2)-O(10) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.59 Å. The P(2)-O(8) bond length is 1.55 Å. The P(2)-O(9) bond length is 1.55 Å. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a 3-coordinate geometry to one Li(2), one Nb(3), and one P(2) atom. In the second O site, O(10) is bonded in a 3-coordinate geometry to one Li(2), one Nb(3), and one P(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one Nb(1), and one P(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Nb(2), and one Nb(3) atom. In the seventh O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Nb(1), and one P(1) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Nb(1), and one Nb(2) atom. In the ninth O site, O(7) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(2) atom. In the tenth O site, O(8) is bonded in a 3-coordinate geometry to one Li(1), one Nb(2), and one P(2) atom.