Materials Data on VSiP2O9 by Materials Project
VSiP2O9 crystallizes in the tetragonal P4/ncc space group. The structure is three-dimensional. V4+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.64–2.53 Å. Si4+ is bonded to four equivalent O2- atoms to form SiO4 tetrahedra that share corners with four equivalent PO4 tetrahedra. All Si–O bond lengths are 1.63 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent SiO4 tetrahedra. There is two shorter (1.50 Å) and two longer (1.59 Å) P–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent V4+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one V4+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one P5+ atom.