Solving Complex and Disordered Surface Structures with Electron Diffraction

Abstract

The past of surface structure determination with low-energy electron diffraction (LEED) will be briefly reviewed, setting the stage for a discussion of recent and future developments. The aim of these developments is to solve complex and disordered surface structures. Some efficient solutions to the theoretical and experimental problems will be presented. Since the theoretical problems dominate, the emphasis will be on theoretical approaches to the calcula tion of the multiple scattering of electrons through complex and disordered surfaces.

Directed search methods for surface structure determination by LEED

“…Both are consequences of the complexity arising from the presence of many independent atoms in the surface unit cell ( 4,5). Thus, while an a priori structure determination of a simple surface such as Cu(100) can be performed on a microcomputer (6), an organic molecule adsorbed on a catalyst substrate or a complex reconstructed semiconductor surface requires many hours of supercomputer time.…”

“…So far, this approach appears to require one to guess the correct atomic coordinates with an accuracy of better than 0.1A. 4 . .…”