The art of zeolite structure analysis

Abstract

A number of new techniques for determining zeolite framework structures have been developed in recent years. Micron-sized single crystals can now be examined using microdiffraction instruments at synchrotron radiation facilities, direct methods of structure solution have been adapted to the problems inherent to powder diffraction data, two zeolite-specific structure determination algorithms (FOCUS and simulated annealing) have been realized, a powder diffraction approach exploiting preferred orientation has been developed, and electron crystallography is emerging as a viable alternative to X-ray diffraction methods. Once a framework structure has been determined, the process of completing and refining the structure begins. The whole process from data collection to final structure can be long and tortuous. It is not straightforward—it is an art.