Perhaps the most controversial aspeat of this volume is the number (V) assigned to the aonferenae in this series. Actually, the first aonferenae to be held under the title '~tomia Collisions in Solids" was held at Sussex University in England in 1969 and the seaond at Gausdal, Norway in 19?1, whiah would logically make the aonferenae held at Gatlinburg, Tennessee, U. S. A. in 19?3 the third (III). However, the appearance of the proceedings of the 19?1 Gausdal Conference (published by Gordon and Breaahj bore the number IV. The reasoning behind this was that, in. faat, two pre- vious aonferenaes had been largely dedicated to the same subjeat area. The first of these was at Aarhus, Denmark in 1965 and the seaond in 196? was held in Chalk River, Canada. Henae, the number V for the 19?3 meeting. Actually, the aonferenae aan easily be traaed baak to Paris, Franae in 196l when it went under the colorful title of '~e Bom- bardement Ionique. " In 1962 a small aonferenae was held at Oak Ridge, Tennessee, U. S. A. at whiah the discovery of channeling was first formally annunciated. This was followed by aonferenaes at Chalk River, Canada in 1963 and at Harwell, England in 1964. More- over, immediately following the Chalk River conference in 196? there was a aonferenae on higher energy collisions at Brookhaven, New York, U. S. A. Thus, strictly speaking, the Gatlinburg meeting is the tenth (X) in the series.

Applying a unified quantum approach, contributors offer fresh insights into the theoretical developments in the excitation energy transfer processes in condensed matter. This comprehensive volume examines Frenkel and Wannier excitonic processes; rates of excitonic processes; theory of laser sputter and polymer ablation; and polarons, excitonic polarons and self-trapping.

The book addresses graduate students as well as scientists interested in applications of the standard model for strong and electroweak interactions to experimentally determinable quantities. Computer simulations and the relations between various approaches to quantum field theory, such as perturbative methods, lattice methods and effective theories, are also discussed.

This volume presents the contributions delivered at the "Josef-Loschmidt-Sympo sium," which took place in Vienna, June 25-27, 1995. The symposium was arranged to honor Josef Loschmidt one hundred years after his death (8 July 1895), to evaluate the sig nificance of his contributions to chemistry and physics from a modem point of view and to trace the development of scientific fields in which he had done pioneering work. Loschmidt is widely known for the first calculation of the size of molecules (1865/66), which also led to values for the number of molecules in unit gas volume and for the mass of molecules. With critical analyses of problems in statistical physics he made important contributions to the development of that field, "Loschmidt's paradoxon" continuing to be a point of departure for present day studies and discussions. For decades there was little awareness that Loschmidt was a pioneer in organic struc tural chemistry. Only in recent years has Loschmidt's first scientific publication "Chemis che Studien I", published in 1861, become more widely known and it is now recognized that with his ideas on the structure of organic molecules he was greatly ahead of the chemists of that time. The papers in these proceedings are arranged in three sections: l. Organic structural chemistry (Chapters 1-12). 2. Physics and physical chemistry (Chapters 13-26). 3. Loschmidt's biography, Loschmidt's world (Chapters 27-33).

The aim of the workshop was to bring together specialists in various fields where non-exponential relaxation is observed in order to compare models and experimental results and to examine the general physical principles governing this type of behaviour. Non-exponential relaxation is found in extremely diverse physical systems all of which can be classified as complex. The form of the relaxation is generally parametrized using logarithmic, algebraic or stretched exponential decay forms. The conceptually simplest mechanism for the non-exponential decay is a spectrum of relaxation rates due to non-interacting units each of which relaxes with a different intrinsic time constant. Clear experimental examples can be given where for instance the relaxation of a collection of isolated polymer molecules leads to an overall stretched exponential decay. Non-exponential relaxation is observed in all strongly interacting complex systems (structural glasses, spin glasses, etc ... ) where each elementary unit is in interaction with many other units.

The motivations, goals and general culture of theoretical physics and mathematics are different. Most practitioners of either discipline have no necessity for most of the time to keep abreast of the latest developments in the other. However on occasion newly developed mathematical concepts become relevant in theoretical physics and the less rigorous theoretical physics framework may prove valuable in understanding and suggesting new theorems and approaches in pure mathematics. Such interdis ciplinary successes invariably cause much rejoicing, as over a prodigal son returned. In recent years the framework provided by quantum field theory and functional in tegrals, developed over half a century in theoretical physics, have proved a fertile soil for developments in low dimensional topology and especially knot theory. Given this background it was particularly pleasing that NATO was able to generously sup port an Advanced Research Workshop to be held in Cambridge, England from 6th to 12th September 1992 with the title Low Dimensional Topology and Quantum Field Theory. Although independently organised this overlapped as far as some speak ers were concerned with a longer term programme with the same title organised by Professor M Green, Professor E Corrigan and Dr R Lickorish. The contents of this proceedings of the workshop demonstrate the breadth of topics now of interest on the interface between theoretical physics and mathematics as well as the sophistication of the mathematical tools required in current theoretical physics."

This book had its origins in lectures presented at EPFL, Lausanne, during two separate visits (the most recent being to IRRMA). The author is most grateful to Professors A. Baldereschi, R. Car, and A. Quattropani for making these visits possible, and for the splendidly stimulating environment provided. Professors S. Baroni and R. Resta also influenced considerably the presentation of material by constructive help and comments. Most importantly, Chapters 4 and 5 were originally prepared for a review article by Professor G. Senatore, then at Pavia and now in Trieste, and myself for Reviews of Modem Physics (1994). In the 'course of this collaboration, he has taught me a great deal, especially about quantum Monte Carlo procedures, and Chapter 5 is based directly on this review article. Also in Chapter 4, my original draft on Gutzwiller's method has been transformed by his deeper understanding; again this is reflected directly in Chapter 4; especially in the earlier sections. In addition to the above background, it is relevant here to point out that, as a backcloth for the present, largely "state of the art," account, there are two highly relevant earlier books: The Many-body Problem in Quantum Mechanics with W.

The theory of the inhomogeneous electron gas had its origin in the Thomas Fermi statistical theory, which is discussed in the first chapter of this book. This already leads to significant physical results for the binding energies of atomic ions, though because it leaves out shell structure the results of such a theory cannot reflect the richness of the Periodic Table. Therefore, for a long time, the earlier method proposed by Hartree, in which each electron is assigned its own personal wave function and energy, dominated atomic theory. The extension of the Hartree theory by Fock, to include exchange, had its parallel in the density description when Dirac showed how to incorporate exchange in the Thomas-Fermi theory. Considerably later, in 1951, Slater, in an important paper, showed how a result similar to but not identical with that of Dirac followed as a simplification of the Hartree-Fock method. It was Gombas and other workers who recognized that one could also incorporate electron correlation consistently into the Thomas-Fermi-Dirac theory by using uniform electron gas relations locally, and progress had been made along all these avenues by the 1950s."

From March 30th to April 3rd, 1992, a NATO Advanced Research workshop entitled "Time Dependent Quantum Molecular Dynamics: Theory and Experiment" was held at Snowbird, Utah. The organizing committee consisted of J. BROECKHOVE (Antwerp, Belgium), L. CEDERBAUM (Heidelberg, Germany), L. LATHOUWERS (Antwerp, Belgium), N. OHRN (Gainesville, Florida) and J. SIMONS (Salt Lake City, Utah). Fifty-two participants from eleven different countries attended the meeting at which thirty-three talks and one poster session were held. Twenty-eight participants submitted contributions to the proceedings of the meeting, which are reproduced in this volume. The workshop brought together experts in different areas 0 f molecular quantum dynamics, all adhering to the time dependent approach. The aim was to discuss and compare methods and applications. The ~amiliarityo~ the aUdience with the concepts o~ time dependent approaches greatly facilitated topical discussions and probing towards new applications. A broad area of subject matter was covered including time resolved laser chemistry, intramolecular dynamics, photodissociation dynamics, reactive and inelastic collisions as well as new time dependent methodologies. This diversity in applications is reflected in the contributions included in this volume .

This volume contains the Proceedings of the Third International Conference on Navier-Stokes Equations and Related Nonlinear Problems. The conference was held in Funchal (Madeira, Portugal), on May 21-27, 1994. In addition to the editor, the organizers were Carlos Albuquerque (FC, University of Lisbon), Casimiro Silva (University of Madeira) and Juha Videman (1ST, Technical University of Lisbon). This meeting, following two other successful events of similar type held in Thurnau (Germany) in 1992 and in Cento (Italy) in 1993, brought together, to the majestically beautiful island of Madeira, more than 60 specialists from all around the world, of which about two thirds were invited lecturers. The main interest of the meeting was focused on the mathematical analysis of nonlinear phenomena in fluid mechanics. During the conference, we noticed that this area seems to provide, today more than ever, challenging and increasingly important problems motivating the research of both theoretical and numerical analysts. This volume collects 32 articles selected from the invited lectures and contributed papers given during the conference. The main topics covered include: Flows in Unbounded Domains; Flows in Bounded Domains; Compressible Fluids; Free Boundary Problems; Non-Newtonian Fluids; Related Problems and Numerical Approximations. The contributions present original results or new surveys on recent developments, giving directions for future research. I express my gratitude to all the authors and I am glad to recognize the scientific level and the actual interest of the articles.

The 7th International Cyclotron Conference, In addition to 25 invited papers, a total of held in ZUrich from 19-22 August, 1975, was atten 103 papers were submitted for presentation at the ded by 231 registered . participants from 21 different conference. In order to avoid parallel sessions, countries. Visitors came from all 5 continents, only 30 papers were selected for oral presentation. showing the truly international character of the The rest of the papers were displayed, with great so-called cyclotron family. After a slight slump success, in two poster sessions, with the authors around 1970 in science funding in general, it is explaining in detail to interested participants encouraging to see that cyclotrons emerge again their reports. The high-light of the banquet was the with a promising future, rich in applications. For after dinner speech by M. S. Livingston on the history an informal summary of the topics and highlights of of the cyclotron. The hit of the ladies program was this conference, the reader is referred to the back the visit to a local chocolate factory. The rumour inside cover of these proceedings. There Henry goes that some conference participants too preferred Blosser, from Michigan State University, a very this visit to the session talks! active pioneer in the cyclotron field, put down his impressions in a matter of ten minutes after some The list of old-timers who participated in all small pressure from the editor.

In the slightly more than thirty years since its formulation, the Hubbard model has become a central component of modern many-body physics. It provides a paradigm for strongly correlated, interacting electronic systems and offers insights not only into the general underlying mathematical structure of many-body systems but also into the experimental behavior of many novel electronic materials. In condensed matter physics, the Hubbard model represents the simplest theoret ical framework for describing interacting electrons in a crystal lattice. Containing only two explicit parameters - the ratio ("Ujt") between the Coulomb repulsion and the kinetic energy of the electrons, and the filling (p) of the available electronic band - and one implicit parameter - the structure of the underlying lattice - it appears nonetheless capable of capturing behavior ranging from metallic to insulating and from magnetism to superconductivity. Introduced originally as a model of magnetism of transition met als, the Hubbard model has seen a spectacular recent renaissance in connection with possible applications to high-Tc superconductivity, for which particular emphasis has been placed on the phase diagram of the two-dimensional variant of the model. In mathematical physics, the Hubbard model has also had an essential role. The solution by Lieb and Wu of the one-dimensional Hubbard model by Bethe Ansatz provided the stimulus for a broad and continuing effort to study "solvable" many-body models. In higher dimensions, there have been important but isolated exact results (e. g., N agoaka's Theorem)."

This volume contains the invited papers and selected contributed papers presented at the biennial International Symposium on ELECTRON COLLISIONS WITH MOLECULES, CLUSTERS AND SURF ACES held at Royal Holloway, University of London from 29th to 30th July, 1993. This Symposium was a Satellite Meeting of the XVIII International Conference on the Physics of Electronic and Atomic Collisions (ICPEAC) and follows a 16 year tradition of Satellite Conferences in related areas of collisions held in association with previous ICPEAC's. In the past each of these electron -molecule symposia covered the broad field of electron-molecule scattering at rather low energies, but also included hot topics. This time as well as covering the whole field, well defined electron collisions with clusters and with particles in the complex potential of a surface were emphasized. Not many details are known about such collisions, although they become more and more important in surface characterisation, plasma-wall interactions, electron induced desorption and reorganisation of adsorbed particles. Recently, much work, theoretical and experimental, has been devoted to electron collisions with rather large carbon, silicon and halogen containing molecules. These problems are of relevance in plasma assisted thin film formation and etching of surfaces and can now be approached with advanced theoretical methods and experimental equipment.

The Nato Advanced Study Institute "Phase Transitions in Liquid Crystals" was held May 2-12, 1991, in Erice, Sicily. This was the 16th conference organized by the International School of Quantum Electronics, under the auspices of the "Ettore Majorana" Centre for Scientific Culture. The subject of "Liquid Crystals" has made amazing progress since the last ISQE Course on this subject in 1985. The present Proceedings give a tutorial introduction to today's most important areas, as well as a review of current results by leading researchers. We have brought together some of the world's acknowledged experts in the field to summarize both the present state of their research and its background. Most of the lecturers attended all the lectures and devoted their spare hours to stimulating discussions. We would like to thank them all for their admirable contributions. The Institute also took advantage of a very active audience; most of the students were active researchers in the field and contributed with discussions and seminars. Some of these student seminars are also included in these Proceedings. We did not modify the original manuscripts in editing this book, but we did group them according to the following topics: 1) "Theoretical Foundations"; 2) "Thermotropic Liquid Crystals"; 3) "Ferroelectric Liquid Crystals"; 4) "Polymeric Liquid Crystals"; and 5) "Lyotropic Liquid Crystals".

These are the proceedings of the 141h Winter \Vorkshop on Nuclear Dynamics, the latest of a serif'S of workshops that was started in 1~)78. This series has grown into a tradition. bringing together experimental and theoretical expertise from all areas of the study of nudear dynamics. Following tllf' tradition of the Workshop the program covered a broad range of topics aerof'S a large energy range. At the low energy end llluitifragmentation and its relationship to the nuclear liquid to gas phase transition was disclIssf'd in grf'at df'- tail. New pxpf'rimental data, refined analysis techniques, and new theoretical effort have lead to considerable progress. In the AGS energy range we see the emergence of systematic data that contribute to our understanding of the reaction dynamics. The workshop also showf'd that at CERN energies Itadronic data become much more precise and complet.e and a renewed emphasis on basic hadronic processes and hadronic struc- ture as a precondition to understand the initial conditions and a basis for systematic comparisons. Wolfgang Bauer Michigan State Univcr'sity Hans-Georg Ritter Lawrence Berkeley National Laboratory v PREVIOUS WORKSHOPS The following table contains a list of the dates and locations of the previous Winter Workshops on Nuclear Dynamics as well as the members of the organizing committees. The chairpersons of the conferences are underlined.

The seventh Advanced Study Institute (ASI) on Techniques and Concepts of High Energy Physics was held for the second time at the Club St. Croix, in St. Croix, U.S. Virgin Islands. The ASI brought together a total of 75 participants, from 19 countries. The primary support for the meeting was again provided by the Scientific Affairs Division of NATO. The ASI was cosponsored by the U.S. Department of Energy, by Fermilab, by the National Science Foundation, and by the University of Rochester. A special contribution from the Oliver S. and Jennie R. Donaldson Charitable Trust provided an important degree of flexibility, as well as support for worthy students from developing countries. As in the case of the previous ASIs, the scientific program was designed for advanced graduate students and recent PhD recipients in experimental particle physics. The present volume of lectures should complement the material published in the first six ASIs, and prove to be of value to a wider audience of physicists.

Covering both theory and applications, this important work provides a comprehensive introduction to the modern theory of X-ray and electronic spectra of free atoms. Romas Karazija discusses methods of angular momenta, irreducible tensorial operators, and coefficients of fractional parentage and their use in determining cross sections and probabilities of elementary processes. In addition, Karazija addresses the structure of electronic shells with inner vacancies and many-body effects.

Multiply charged ions have always been in the focus of atomic physics, astrophysics, plasma physics, and theoretical physics. Within the last few years, strong progress has been achieved in the development of ion sources, ion storage rings, ion traps, and methods to cool ions. As a consequence, nowadays, experiments with ensembles of multiply charged ions of brilliant quality are performed in many laboratories. The broad spectrum of the experiments demonstrates that these ions are an extremely versatile tool for investigations in pure and applied physics. It was the aim of this ASI to bring together scientists working in different fields of research with multiply charged ions in order to get an overview of the state of the art, to sound out possibilities for fruitful cooperations, and to discuss perspectives for the future. Accordingly, the programme of the ASI reached from established areas like QED calculations, weak interactions, x-ray astronomy, x-ray lasers, multi photon excitation, heavy-ion induced fusion, and ion-surface interactions up to the very recently opened areas like bound-beta decay, laser and x-ray spectroscopy, and spectrometry of ions in rings and traps, and the interaction of highly charged ions with biological cells. Impressive progress in nearly all of the fields could be reported during the meeting which is documented by the contributions to this volume. The theoretical understand ing of QED and correlation effects in few-electron heavy ions is rapidly developing."

For more than a century, studies of atomic hydrogen have been a rich source of scientific discoveries. These began with the Balmer series in 1885 and the early quantum theories of the atom, and later included the development of QED and the first successful gauge field theory. Today, hydrogen and its relatives continue to provide new fundamental information, as witnessed by the contributions to this book. The printed volume contains invited reviews on the spectroscopy of hydrogen, muonium, positronium, few-electron ions and exotic atoms, together with related topics such as frequency metrology and the determination of fundamental constants. The accompanying CD contains, in addition to these reviews, a further 40 contributed papers also presented at the conference "Hydrogen Atom 2" held in summer 2000. Finally, to facilitate a historical comparison, the CD also contains the proceedings of the first "Hydrogen Atom" conference of 1988. The book includes a foreword by Norman F. Ramsey.

This book reviews all the state-of-the-art simulation methods used to investigate the atomistic-scale properties of technologically important oxide materials. Previous and many recent results are carefully discussed.

The International Workshop on Quantum Communications and Measurement was held at the University of Nottingham from July 10-16, 1994. It followed the successful meeting on Quantum Aspects of Optical Communications in Paris in November 1990. This time the conference was devoted to mathematical, physical and engineering aspects of quantum noise, signal processing and quantum informa tion in open systems, quantum channels, and optical communications. It brought research workers in the experimental and engineering aspects of quantum optics and communication systems into contact with theoreticians working in quantum probability and measurement theory. The workshop was attended by more than 130 participants from 22 different countries. The largest groups after the UK (31)] were from Japan (19) and from Russia (14). The subjects discussed included the mathematical foundations of quantum communication systems, experiments and devices, the problem of collapse and continuous measurement, quantum input and output processes, causality and nondemolition observation, squeezed states, quan tum jumps, state diffusion and spontaneous localization, filtering and control in quantum systems, and new quantum optical phenomena and effects, including non classical light. These new mathematical and physical ideas were stimulated by recent advances in generation and detection of light with low quantum noise and the development of techniques for trapping a single atom over an extended period of time, making it possible to observe individual quantum phenomena at the macroscopic level."

of available information. Even more importantly, some authors who have contributed substantially to an area may have been overlooked. For this I apologize. I have, however, not attempted to trace techniques or observa tions historically, so there is no implication (unless specified) that the authors referred to were or were not the originators of a given method or observation. I would like to acknowledge discussions with co-workers at SFU for input relative to their specialties, to acknowledge the help of students who have pointed out errors and difficulties in the earlier presentation, and to acknowledge the infinite patience of my wife Phyllis while I spent my sabbatical and more in libraries and punching computers. S. Roy Morrison 0 1 Contents Notation XV 1. Introduction 1 1. 1. Surface States and Surface Sites . 1 1. 1. 1. The Chemical versus Electronic Representation of the Surface. 1 1. 1. 2. The Surface State on the Band Diagram 4 1. 1. 3. The Fermi Energy in the Surface State Model. 6 1. 1. 4. Need for Both Surface Site and Surface State Models 6 1. 2. Bonding of Foreign Species to the Solid Surface 7 1. 2. 1. Types of Interaction. 7 1. 2. 2. The Chemical Bond . 10 1. 2. 3. Acid and Basic Surface Sites on Solids . 13 1. 2. 4. Adsorbate Bonding on Various Solid Types. 16 1. 2. 5. Movement of Surface Atoms: Relaxation, Reconstruction, and Relocation ."

This book is the result of a NATO Advanced Research Workshop held in Vimeiro, Portugal, in May 1992. The objectives of this Workshop were: i) to promote exchange of knowledge between experts in various fields of discharge modeling, plasma diagnostics and microwave plasma applications; ii) to assess the state-of-the-art in this field from a multidisciplinary viewpoint; iii) to identify basic points needing clarification and to estab- lish basic guidelines for future research; iv) to compare the properties of microwave dis- charges to those of RF discharges, as plasma sources for specific applications. Most of the contributors to this book are well known scientists in the field of mi- crowave discharge sources, modeling, diagnostics and applications. The book provides an up-to-date review in this field which should be useful for both the fundamentalists and those using these systems in applications such as surface treatment and elemental analysis. We are gmteful to a number of organizations for providing the fmancial assistance that made the Workshop possible. Foremost is the NATO Scientific Affairs Division, which provided the major contribution for the Workshop. In addition, the following Por- tuguese sources made contributions: Instituto Nacional de Investiga~iio Cientifica, Junta Nacional de Investiga~iio Cientifica e Tecnologica, Centro de Electrodinamica da Univer- sidade Tecnica de Lisboa, Instituto Superior Tecnico, Banco Nacional Ultmmarino, and Regiiio de Turismo do Oeste.

This book has been written as part of a series of scientific books being published by Plenum Press. The scope of the series is to review a chosen topic in each volume. To supplement this information, the abstracts to the most important references cited in the text are reprinted, thus allowing the reader to find in-depth material without having to refer to many additional publications. This volume is dedicated to the field of dry (plasma) etching, as applied in silicon semiconductor processing. Although a number of books have appeared dealing with this area of physics and chemistry, these all deal with parts of the field. This book is unique in that it gives a compact, yet complete, in-depth overview of fundamentals, systems, processes, tools, and applications of etching with gas plasmas for VLSI. Examples are given throughout the fundamental sections, in order to give the reader a better insight in the meaning and magnitude of the many parameters relevant to dry etching. Electrical engineering concepts are emphasized to explain the pros and cons of reactor concepts and excitation frequency ranges. In the description of practical applications, extensive use is made of cross-referencing between processes and materials, as well as theory and practice. It is thus intended to provide a total model for understanding dry etching. The book has been written such that no previous knowledge of the subject is required. It is intended as a review of all aspects of dry etching for silicon semiconductor processing.

Following the first Capri School on Photon Correlation Spectroscopy held in July 1973 and published earlier in this series (Series B: Physics v.3) a second Capri NATO Advanced Study Institute on this topic was held at the Hotei Luna from 26 July to 6 August 1976. This volume contains the invited lecture courses and seminars and some of the contributed seminars presented at this Institute. Much had happened in the field in the intervening three years and it was the intention of the Organising Committee to build on the previous courses * without detailed repetition of fundamentals. and to extend the coverage widely over the use of photon-correla tion methods for the temporal or spectral analysis of fluctuating light sources. In particular, the rapid expansion of these methods for the measurement of macroscopic motion by Laser Doppler Veloci metry was given special emphasis as is indicated in the title. The members of the Organizing Committee were: E R Pike, RSRE, Malvern, UK } _ Co-directors H Z Cummins, CCNY, New York, USA M Bertolotti, University of Rome, Italy - Local Organiser P Pusey, RSRE, Malvern, UK - Treasurer V DeGiorgio, CISE, Milan, Italy P Lallemand, ENS, Paris, France Pierre de Gennes assisted the Committee during the planning of the Institute but was unfortunately prevented at the last minute from attending.