The role of long-range van der Waals forces in the relative stability of SiO2-zeolites

The influence of long-range dispersion forces in the stability of silica zeolites is explored by considering periodic hybrid-DFT calculations. It is shown that a widely used functional such as B3LYP is unable to reproduce the experimental stability trend of a large set of SiO2 open frameworks when considering high-level basis sets. Correcting the method to account for dispersion with a straightforward Londonlike energy correction term allows recovering the experimental trend, being the agreement particularly noticeable for PBEO-D. These results provide a strong indication of the relevance of long-range dispersion forces in the stability trend of porous materials. (C) 2014 Elsevier B.V. All rights reserved.