LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2.sqrt. 3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (.sqrt. 3 x .sqrt. 3) reconstruction on the (111) face of the .cap alpha.-CuAl alloy has been determined.

Surface crystallography plays the same fundamental role in surface science which bulk crystallography has played so successfully in solid-state physics and chemistry. The atomic-scale structure is one of the most important aspects in the understanding of the behavior of surfaces in such widely diverse fields as heterogeneous catalysis, microelectronics, adhesion, lubrication, cor rosion, coatings, and solid-solid and solid-liquid interfaces. Low-Energy Electron Diffraction or LEED has become the prime tech nique used to determine atomic locations at surfaces. On one hand, LEED has yielded the most numerous and complete structural results to date (almost 200 structures), while on the other, LEED has been regarded as the "technique to beat" by a variety of other surface crystallographic methods, such as photoemission, SEXAFS, ion scattering and atomic diffraction. Although these other approaches have had impressive successes, LEED has remained the most productive technique and has shown the most versatility of application: from adsorbed rare gases, to reconstructed surfaces of sem iconductors and metals, to molecules adsorbed on metals. However, these statements should not be viewed as excessively dogmatic since all surface sensitive techniques retain untapped potentials that will undoubtedly be explored and exploited. Moreover, surface science remains a multi-technique endeavor. In particular, LEED never has been and never will be self sufficient. LEED has evolved considerably and, in fact, has reached a watershed.

Low Energy Electron Diffraction (LEED) is one of the most commonly used techniques for crystal surface characterization at the atomic level. This book is designed to provide all the essential background information necessary to carry out surface crystallography using LEED.

This timely text covers the theory and practice of surface and nanostructure determination by low-energy electron diffraction (LEED) and surface X-ray diffraction (SXRD): it is the first book on such quantitative structure analysis in over 30 years. It provides a detailed description of the theory, including cutting-edge developments and tested experimental methods. The focus is on quantitative techniques, while the qualitative interpretation of the LEED pattern without quantitative I(V) analysis is also included. Topics covered include the future study of nanoparticles, quasicrystals, thermal parameters, disorder and modulations of surfaces with LEED, with introductory sections enabling the non-specialist to follow all the concepts and applications discussed. With numerous colour figures throughout, this text is ideal for undergraduate and graduate students and researchers, whether experimentalists or theorists, in the fields of surface science, nanoscience and related technologies. It can serve as a textbook for graduate-level courses of one or two semesters.