Li3Ti2(PO4)3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and two equivalent O(2) atoms. In the second Li site, Li(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted LiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Ti(1)O6 octahedra. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form TiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and  a faceface with one Li(2)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-48°. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-44°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Ti(1), and one P(2) atom. In the second O site, O(2) is bonded to one Li(2), two equivalent Li(1), one Ti(1), and one P(1) atom to form distorted corner-sharing OLi3TiP trigonal bipyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), one Ti(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Ti(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(1), one Li(2), one Ti(1), and one P(2) atom.
Li3Ti2(PO4)3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and two equivalent O(2) atoms. The Li(1)-O(1) bond length is 2.24 Å. The Li(1)-O(3) bond length is 1.99 Å. The Li(1)-O(4) bond length is 2.26 Å. The Li(1)-O(6) bond length is 2.63 Å. There is one shorter (2.33 Å) and one longer (2.41 Å) Li(1)-O(2) bond length. In the second Li site, Li(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted LiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Ti(1)O6 octahedra. Both Li(2)-O(2) bond lengths are 2.32 Å. Both Li(2)-O(3) bond lengths are 2.23 Å. Both Li(2)-O(6) bond lengths are 2.22 Å. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form TiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and  a faceface with one Li(2)O6 octahedra. The Ti(1)-O(1) bond length is 2.04 Å. The Ti(1)-O(2) bond length is 2.08 Å. The Ti(1)-O(3) bond length is 2.10 Å. The Ti(1)-O(4) bond length is 2.05 Å. The Ti(1)-O(5) bond length is 1.94 Å. The Ti(1)-O(6) bond length is 2.10 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-48°. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.53 Å. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with two equivalent Li(2)O6 octahedra and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-44°. Both P(2)-O(1) bond lengths are 1.56 Å. Both P(2)-O(6) bond lengths are 1.56 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Ti(1), and one P(2) atom. In the second O site, O(2) is bonded to one Li(2), two equivalent Li(1), one Ti(1), and one P(1) atom to form distorted corner-sharing OLi3TiP trigonal bipyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), one Ti(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Ti(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(1), one Li(2), one Ti(1), and one P(2) atom.