DOE OSTI2020
CaVSiO5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.63 Å. V4+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent VO6 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of V–O bond distances ranging from 1.85–2.02 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent VO6 octahedra. The corner-sharing octahedra tilt angles range from 38–54°. All Si–O bond lengths are 1.65 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two equivalent V4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one V4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one V4+, and one Si4+ atom.