LiTiP2O7 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form distorted LiO5 square pyramids that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles are 68°. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form TiO6 octahedra that share  a cornercorner with one Li(1)O5 square pyramid, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Li(1)O5 square pyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with three equivalent Li(1)O5 square pyramids, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with two equivalent Li(1)O5 square pyramids, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 39-56°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Ti(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Ti(1), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Ti(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Ti(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Ti(1), and one P(2) atom.
LiTiP2O7 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form distorted LiO5 square pyramids that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles are 68°. The Li(1)-O(1) bond length is 2.19 Å. The Li(1)-O(2) bond length is 2.30 Å. The Li(1)-O(3) bond length is 2.45 Å. The Li(1)-O(5) bond length is 2.16 Å. The Li(1)-O(7) bond length is 2.30 Å. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form TiO6 octahedra that share  a cornercorner with one Li(1)O5 square pyramid, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Li(1)O5 square pyramids. The Ti(1)-O(1) bond length is 2.10 Å. The Ti(1)-O(2) bond length is 2.03 Å. The Ti(1)-O(3) bond length is 2.05 Å. The Ti(1)-O(4) bond length is 1.99 Å. The Ti(1)-O(5) bond length is 2.09 Å. The Ti(1)-O(7) bond length is 2.15 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with three equivalent Li(1)O5 square pyramids, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-55°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(5) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.61 Å. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with two equivalent Li(1)O5 square pyramids, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 39-56°. The P(2)-O(2) bond length is 1.54 Å. The P(2)-O(4) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.62 Å. The P(2)-O(7) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Ti(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Ti(1), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Ti(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Ti(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(1), one Ti(1), and one P(2) atom.