Determining the structure of zeolite frameworks at high pressures

The study of porous materials under high-pressure conditions is crucial for the understanding and development of structure-property relationships. Zeolites are a diverse class of microporous materials with an extensive range of properties and applications, which can be attributed to their unique pore systems, channel dimensions and mechanical stability. Due to their complex frameworks and compositions, determining the structures of zeolite materials at high pressures is particularly challenging. Here, we present our method which involves geometric modelling, implemented in GASP (Geometric Analysis of Structural Polyhedra) software, to obtain crystal structures at high-pressures when Rietveld refinements alone fall short. We show that GASP can be used to simulate theoretical compression mechanisms of zeolite frameworks at the atomic level, providing optimised structural models as reasonable starting points for full crystal structure analysis. Finally, we discuss the potential of geometric modelling to predict high-pressure behaviour of other known and hypothetical structures, which may find use in future applications. We anticipate that GASP software will be a powerful tool that can assist in determining the crystal structures of zeolite frameworks at high pressures.