Li2VP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with three equivalent V(1)O5 trigonal bipyramids. V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form VO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. 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 P(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent V(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent V(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one V(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Li(2), one V(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 V(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one V(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 V(1), 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.
Li2VP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Li(1)-O(3) bond length is 2.60 Å. The Li(1)-O(4) bond length is 2.27 Å. The Li(1)-O(5) bond length is 2.09 Å. The Li(1)-O(6) bond length is 2.17 Å. The Li(1)-O(7) bond length is 2.01 Å. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with three equivalent V(1)O5 trigonal bipyramids. The Li(2)-O(2) bond length is 2.03 Å. The Li(2)-O(3) bond length is 2.00 Å. The Li(2)-O(4) bond length is 2.05 Å. The Li(2)-O(7) bond length is 1.93 Å. V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form VO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The V(1)-O(2) bond length is 2.17 Å. The V(1)-O(3) bond length is 2.14 Å. The V(1)-O(4) bond length is 2.21 Å. The V(1)-O(5) bond length is 2.16 Å. The V(1)-O(6) bond length is 2.13 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 P(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent V(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.61 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent V(1)O5 trigonal bipyramids. The P(2)-O(1) bond length is 1.66 Å. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.51 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one V(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Li(2), one V(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 V(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one V(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 V(1), 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.