V2Si2O7 crystallizes in the triclinic P-1 space group. V(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with three equivalent V(1)O6 octahedra. 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 six equivalent V(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-63°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent V(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent V(1) 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 linear geometry to two equivalent Si(1) atoms.
V2Si2O7 crystallizes in the triclinic P-1 space group. V(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with three equivalent V(1)O6 octahedra. There is one shorter (2.03 Å) and one longer (2.20 Å) V(1)-O(1) bond length. There is one shorter (2.01 Å) and one longer (2.16 Å) V(1)-O(2) bond length. There is one shorter (2.00 Å) and one longer (2.10 Å) V(1)-O(3) bond length. 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 six equivalent V(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-63°. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.61 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent V(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent V(1) 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 linear geometry to two equivalent Si(1) atoms.