Li2VSiCO7 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 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent V(1)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 63-71°. V(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted VO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra, corners with two equivalent Li(2)O5 trigonal bipyramids, and  an edgeedge with one Li(2)O5 trigonal bipyramid. Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with four equivalent V(1)O6 octahedra and corners with three equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 34-47°. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one V(1), and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one V(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(1), one V(1), and one Si(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 Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one V(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(2), one V(1), and one Si(1) atom.
Li2VSiCO7 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 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. The Li(1)-O(1) bond length is 1.96 Å. The Li(1)-O(2) bond length is 2.01 Å. The Li(1)-O(4) bond length is 2.09 Å. The Li(1)-O(5) bond length is 2.11 Å. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent V(1)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 63-71°. The Li(2)-O(2) bond length is 2.02 Å. The Li(2)-O(3) bond length is 2.26 Å. The Li(2)-O(5) bond length is 2.16 Å. The Li(2)-O(6) bond length is 2.17 Å. The Li(2)-O(7) bond length is 2.16 Å. V(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted VO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra, corners with two equivalent Li(2)O5 trigonal bipyramids, and  an edgeedge with one Li(2)O5 trigonal bipyramid. The V(1)-O(1) bond length is 2.12 Å. The V(1)-O(3) bond length is 2.06 Å. The V(1)-O(4) bond length is 1.89 Å. The V(1)-O(5) bond length is 2.02 Å. The V(1)-O(6) bond length is 1.85 Å. The V(1)-O(7) bond length is 1.93 Å. Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with four equivalent V(1)O6 octahedra and corners with three equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 34-47°. The Si(1)-O(4) bond length is 1.65 Å. The Si(1)-O(5) bond length is 1.64 Å. The Si(1)-O(6) bond length is 1.64 Å. The Si(1)-O(7) bond length is 1.64 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The C(1)-O(1) bond length is 1.32 Å. The C(1)-O(2) bond length is 1.26 Å. The C(1)-O(3) bond length is 1.31 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one V(1), and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(2), one V(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(1), one V(1), and one Si(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 Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one V(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(2), one V(1), and one Si(1) atom.