Synthesis and structure of pure SiO2 chabazite: the SiO2 polymorph with the lowest framework density

Abstract

A SiO₂ material with the lowest framework density (15.4 SiO₂ nm^–3) and the largest void volume fraction (nearly 50%) ever reported for crystalline silica polymorphs has been synthesised, and its structure solved by direct methods and fully refined using low-resolution powder X-ray diffraction data.