V2Si2O7 crystallizes in the monoclinic C2/c space group. There are two inequivalent V sites. In the first V site, V(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted VO6 pentagonal pyramids that share corners with six equivalent Si(1)O4 tetrahedra,  an edgeedge with one V(2)O6 octahedra, and edges with two equivalent V(1)O6 pentagonal pyramids. In the second V site, V(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form distorted VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra, edges with two equivalent V(2)O6 octahedra, and  an edgeedge with one V(1)O6 pentagonal pyramid. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with three equivalent V(2)O6 octahedra, corners with three equivalent V(1)O6 pentagonal pyramids, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-64°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent V(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent V(2) and one Si(1) atom.
V2Si2O7 crystallizes in the monoclinic C2/c space group. There are two inequivalent V sites. In the first V site, V(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted VO6 pentagonal pyramids that share corners with six equivalent Si(1)O4 tetrahedra,  an edgeedge with one V(2)O6 octahedra, and edges with two equivalent V(1)O6 pentagonal pyramids. Both V(1)-O(2) bond lengths are 2.05 Å. There are two shorter (2.08 Å) and two longer (2.10 Å) V(1)-O(3) bond lengths. In the second V site, V(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form distorted VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra, edges with two equivalent V(2)O6 octahedra, and  an edgeedge with one V(1)O6 pentagonal pyramid. Both V(2)-O(2) bond lengths are 2.05 Å. There are two shorter (2.09 Å) and two longer (2.10 Å) V(2)-O(4) bond lengths. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with three equivalent V(2)O6 octahedra, corners with three equivalent V(1)O6 pentagonal pyramids, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-64°. The Si(1)-O(1) bond length is 1.61 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.65 Å. The Si(1)-O(4) bond length is 1.65 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent V(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent V(2) and one Si(1) atom.