Li2VP2O7 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a see-saw-like geometry to one O(2), one O(3), one O(4), and one O(5) atom. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form distorted LiO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  an edgeedge with one V(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-77°. V(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 VO6 octahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-53°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(2), one V(1), and one P(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one V(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 V(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one V(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one V(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one V(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom.
Li2VP2O7 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a see-saw-like geometry to one O(2), one O(3), one O(4), and one O(5) atom. The Li(1)-O(2) bond length is 2.18 Å. The Li(1)-O(3) bond length is 1.97 Å. The Li(1)-O(4) bond length is 1.98 Å. The Li(1)-O(5) bond length is 2.00 Å. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form distorted LiO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  an edgeedge with one V(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-77°. The Li(2)-O(1) bond length is 2.03 Å. The Li(2)-O(2) bond length is 2.21 Å. The Li(2)-O(5) bond length is 2.07 Å. The Li(2)-O(6) bond length is 1.96 Å. V(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 VO6 octahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The V(1)-O(1) bond length is 2.17 Å. The V(1)-O(2) bond length is 2.18 Å. The V(1)-O(3) bond length is 2.20 Å. The V(1)-O(4) bond length is 2.11 Å. The V(1)-O(5) bond length is 2.24 Å. The V(1)-O(6) bond length is 2.18 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.53 Å. The P(1)-O(5) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.62 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-53°. The P(2)-O(1) bond length is 1.53 Å. The P(2)-O(2) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.62 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(2), one V(1), and one P(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one V(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 V(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one V(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one V(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one V(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom.