On crystal structure imaging of silicalite by HREM

High-resolution electron microscopy (HREM) images of silicalite (ZSM-5) along [010] were taken with a 400-kV EM with a resolution of 1.6 Å. The images contain a dark contrast in the centers of the main channels, where there are no atoms. This contrast is an artifact and is not appreciable in the HREM images which have been published so far. That this problem can be overcome by choosing the proper experimental conditions was confirmed by both computer-simulated and experimental HREM images. Computer image processing is also applicable to this kind of problem