VSiP2O9 crystallizes in the tetragonal P4/ncc space group. V(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. Si(1) is bonded to four equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. P(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(2) is bonded in a distorted single-bond geometry to two equivalent V(1) atoms. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one P(1) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one P(1) atom.
VSiP2O9 crystallizes in the tetragonal P4/ncc space group. V(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. There is one shorter (1.64 Å) and one longer (2.53 Å) V(1)-O(2) bond length. All V(1)-O(3) bond lengths are 2.01 Å. Si(1) is bonded to four equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. All Si(1)-O(1) bond lengths are 1.63 Å. P(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra. Both P(1)-O(1) bond lengths are 1.59 Å. Both P(1)-O(3) bond lengths are 1.50 Å. There are three inequivalent O sites. In the first O site, O(2) is bonded in a distorted single-bond geometry to two equivalent V(1) atoms. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one P(1) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one P(1) atom.