The advances in and applications of x-ray and neutron crystallography form the essence of this new edition of this classic textbook, while maintaining the overall plan of the book that has been well received in the academic community since the first edition in 1977. X-ray crystallography is a universal tool for studying molecular structure, and the complementary nature of neutron diffraction crystallography permits the location of atomic species in crystals which are not easily revealed by X-ray techniques alone, such as hydrogen atoms or other light atoms in the presence of heavier atoms. Thus, a chapter discussing the practice of neutron diffraction techniques, with examples, broadens the scope of the text in a highly desirable way. As with previous editions, the book contains problems to illustrate the work of each chapter, and detailed solutions are provided. Mathematical procedures related to the material of the main body of the book are not discussed in detail, but are quoted where needed with references to standard mathematical texts. To address the computational aspect of crystallography, the suite of computer programs from the fourth edition has been revised and expanded. The programs enable the reader to participate fully in many of the aspects of x-ray crystallography discussed in the book. In particular, the program system XRAY* is interactive, and enables the reader to follow through, at the monitor screen, the computational techniques involved in single-crystal structure determination, albeit in two dimensions, with the data sets provided. Exercises for students can be found in the book, and solutions are available to instructors.

This book collects the lectures given at the NATO Advanced Study Institute on "Atoms in Strong Fields," which took place on the island of Kos, Greece, during the two weeks of October 9-21,1988. The designation "strong field" applies here to an external electromagnetic field that is sufficiently strong to cause highly nonlinear alterations in atomic or molecular struc ture and dynamics. The specific topics treated in this volume fall into two general cater gories, which are those for which strong field effects can be studied in detail in terrestrial laboratories: the dynamics of excited states in static or quasi-static electric and magnetic fields; and the interaction of atoms and molecules with intense laser radiation. In both areas there exist promising opportunities for research of a fundamental nature. An electric field of even a few volts per centimeter can be very strong on the atom ic scale, if it acts upon a weakly bound state. The study of Rydberg states with high reso lution laser spectroscopic techniques has made it possible to follow the transition from weak-field to strong-field behavior in remarkable detail, using static fields of modest lab oratory strength; in the course of this transition the atomic system evolves from one which can be thoroughly understood in terms of field-free quantum numbers, to one which cannot be meaningfully associated at all with the zero-field states of the atom."

For the first half of the 20th Century, low-energy nuclear physics was one of the dominant foci of all of science. Then accelerators prospered and energies rose, leading to an increase of interest in the GeV regime and beyond. The three articles comprising this end-of-century Advances in Nuclear Physics present a fitting and masterful summary of the energy regimes through which nuclear physics has developed and promises to develop in future. One article describes new information about fundamental symmetries found with kV neutrons. Another reviews our progress in understanding nucleon-nucleus scattering up to 1 GeV. The third analyzes dilepton production as a probe for quark-gluon plasmas generated in relativistic heavy-ion collisions.

Density Functional Theory (DFT) has firmly established itself as the workhorse for atomic-level simulations of condensed phases, pure or composite materials and quantum chemical systems. This work offers a rigorous and detailed introduction to the foundations of this theory, up to and including such advanced topics as orbital-dependent functionals as well as both time-dependent and relativistic DFT. Given the many ramifications of contemporary DFT, the text concentrates on the self-contained presentation of the basics of the most widely used DFT variants: this implies a thorough discussion of the corresponding existence theorems and effective single particle equations, as well as of key approximations utilized in implementations. The formal results are complemented by selected quantitative results, which primarily aim at illustrating the strengths and weaknesses of particular approaches or functionals. The structure and content of this book allow a tutorial and modular self-study approach: the reader will find that all concepts of many-body theory which are indispensable for the discussion of DFT - such as the single-particle Green's function or response functions - are introduced step by step, along with the actual DFT material. The same applies to basic notions of solid state theory, such as the Fermi surface of inhomogeneous, interacting systems. In fact, even the language of second quantization is introduced systematically in an Appendix for readers without formal training in many-body theory.

W. HANLE and H. KLEINPOPPEN In 1919, in the first edition of Atombau and Spektrallinien, Sommerfeld referred to the immense amount of information which had been accumu lated during the first period of 60 years of spectroscopic practice. Sommer feld emphasized that the names of Planck and Bohr would be connected forever with the efforts that had been made to understand the physics and the theory of spectral lines. Another period of almost 60 years has elapsed since the first edition of Sommerfeld's famous monograph. As the editors of this monograph, Progress in Atomic Spectroscopy, we feel that the present period is best characterized by the large variety of new spec troscopic methods that have been invented in the last decades. Spectroscopy has always been involved in the field of research on atomic structure and the interaction of light and atoms. The development of new spectroscopic methods (i.e., new as compared to the traditional optical methods) has led to many outstanding achievements, which, together with the increase of activity over the last decades, appear as a kind of renaissance of atomic spectroscopy."

The editors have pleasure in presenting this volume of our review series. We have specialised in three areas: perturbation Monte Carlo, non-linear kinetics and the transfer of radioactive fluids in rocks. These contributions are linked, however, in the demands for optimising complex systems that are a feature of the scale of nuclear power production. Kuniharu Kishida's account of Japanese thinking in the application of modern non-linear theory to reactor kinetics and control comes at a time when the community of control scholars is seeking how to apply the new ideas that have led to the prominence of chaos theory to our field. Pr- lems of maintenance in power reactors are as severe as ever and must be solved for credibility to characterise any new program. As much as 30% of unanticipated down-time, for example, is due to the failure of motor op- ated valves. We need a theory to provide for preventive maintenance. This in turn depends heavily on on-line monitoring to anticipate failure as well as expert systems to schedule preventive treatment. Noise theory with its promise of on-line interpretation of information from inchoate breakdown is the key. It is all too likely that the need to deal with major departures makes a non-linear theory of noise essential. We can be grateful that P- fessor Kishida has provided us with such a consistent account.

The Advanced Study Institute on "Quantum Dynamics of Molecules: The New Experimental Challenge to Theorists," which was sponsored by the Scientific Affairs Division of NATO, was held at Trinity Hall, Ca bridge, England from September 15th till September 29th, 1979. In all, a total of 79 lecturers and students attended the meeting: they had diverse backgrounds in chemistry, physics and mathematics. In my proposal to NATO requesting financial support for an Advanced Study Institute, I suggested that molecular physics was facing a qualitatively new experimental situation in which the exploration of previously inaccessible dynamical phenomena would become of increasing importance. At the same time I was aware that in recent years powerful theoretical techniques, that might prove crucial tools for the interpretation of the new experiments, have been developed in mathematics and theoretical physics. The aim of the ASI was to review at an advanced level these recent developments, juxtaposing new theory with new experimental pos sibilities in the hope that the participants in the-Institute would through their subsequent work increase the awareness of the whole molecular theory community of the changing nature of chemical physics. The recent developments in laser spectroscopy, particle scatter ing experiments and molecular beam technology imply that an entirely new class of phenomena involving molecules in gasses and liquids can now be investigated."

H. J. BEYER AND H. KLEINPOPPEN During the preparation of Parts A and B of Progress in Atomic Spectros copy a few years ago, it soon became obvious that a comprehensive review and description of this field of modern atomic physics could not be achieved within the limitations of a two-volume book. While it was possible to include a large variety of spectroscopic methods, inevitably some fields had to be cut short or left out altogether. Other fields have developed so rapidly that they demand full cover in an additional volume. One of the major problems, already encountered during the prepar ation of the first volumes, was to keep track of new developments and approaches which result in spectroscopic data. We have to look far beyond the area of traditional atomic spectroscopy since methods of atomic and ion collision physics, nuclear physics, and even particle physics all make important contributions to our knowledge of the static and dynamical state of atoms and ions, and thereby greatly add to the continuing fascination of a field of research which has given us so much fundamental knowledge since the middle of the last century. In this volume, we have tried to strike a balance between contribu tions belonging to the more established fields of atomic structure and spectroscopy and those fields where atomic spectroscopy overlaps with other areas."

Recent advances in experimental techniques now enable researchers to produce in a laboratory clusters of atoms of desired composition from any of the elements of the periodic table. This has created a new area of research into novel materials since clusters cannot be regarded either as a "large" molecule or as a fragment of the bulk. Both experimental and theoretical studies are revealing unusual properties that are not ob served in solid state environments. The structures of micro-clusters are found to be significantly distorted from the most symmetric arrangement, some even exhibiting pentagonal symmetry commonly found in icosahedric structures. The unusual stability of certain clusters, now described as "magic number species," shows striking similarities with the nuclear shell structure. The relative stabilities of clusters depend not only on the composition of the clusters but also on their charged states. The studies on spontaneous fragmentation of mUltiply charged clusters, commonly referred to as Coulomb explosion, illustrate the role of electronic bonding mechanisms on stability of clusters. The effect of foreign atoms on geometry and stability of clusters and the interaction of gas atoms with clusters are showing promise for an indepth understanding of chemisorption and catalysis. The magnetic and optical properties are dependent not only on cluster size but also on its geometry. These findings have the potential for aiding industry in the area of micro-electronics and catalysis."

Professor Philip G. Burke, CBE, FRS formally retired on 30 September 1998. To recognise this occasion some of his colleagues, friends, and former students decided to hold a conference in his honour and to present this volume as a dedication to his enormous contribution to the theoretical atomic physics community. The conference and this volume of the invited talks reflect very closely those areas with which he has mostly been asso- ated and his influence internationally on the development of atomic physics coupled with a parallel growth in supercomputing. Phil's wide range of interests include electron-atom/molecule collisions, scattering of photons and electrons by molecules adsorbed on surfaces, collisions involving oriented and chiral molecules, and the development of non-perturbative methods for studying multiphoton processes. His devel- ment of the theory associated with such processes has enabled important advances to be made in our understanding of the associated physics, the interpretation of experimental data, has been invaluable in application to fusion processes, and the study of astrophysical plasmas (observed by both ground- and space-based telescopes). We therefore offer this volume as our token of affection and respect to Philip G. Burke, with the hope that it may also fill a gap in the literature in these important fields.

Volume 17 is the second in a special topic series devoted to modern techniques in protein NMR, under the Biological Magnetic Resonance series. Volume 16, with the subtitle Modern Techniques in Protein NMR , is the first in this series. These two volumes present some of the recent, significant advances in the biomolecular NMR field with emphasis on developments during the last five years. We are honored to have brought together in these volume some of the world s foremost experts who have provided broad leadership in advancing this field. Volume 16 contains - vances in two broad categories: I. Large Proteins, Complexes, and Membrane Proteins and II. Pulse Methods. Volume 17 contains major advances in: I. Com- tational Methods and II. Structure and Dynamics. The opening chapter of volume 17 starts with a consideration of some important aspects of modeling from spectroscopic and diffraction data by Wilfred van Gunsteren and his colleagues. The next two chapters deal with combined automated assignments and protein structure determination, an area of intense research in many laboratories since the traditional manual methods are often inadequate or laborious in handling large volumes of NMR data on large proteins. First, Werner Braun and his associates describe their experience with the NOAH/DIAMOD protocol developed in their laboratory.

This volume is composed of papers (invited and contributed) presented at the International Conference on Coherence and Quantum Optics held at the University of Hyderabad January 5-January 10, 1991. It has been organized by Professor Girish Agarwal and his colleagues at the School of Physics, University of Hyderabad, Hyder abad, India under partial support from the Department of Science and Technology, Government of India, International Center for Theoretical Physics, Trieste, Italy and the National Science Foundation, USA. Without the untiring efforts of Prof. Girish Agarwal and the members of his quantum office group, the Conference and the present volume would not have been possible. Some extraordinary circumstances resulted in a delay of the publication of the present volume. Our sincere apologies to all the authors. We deeply regret the inconvenience caused due to the delay. A debt of gratitude is due to Ms. Kim Bella for the excellent typing job of the different versions and the final version of the manuscript. It is a pleasure to acknowl edge the efforts of Ms. Pat Vann, Mr. Greg Safford and Mr. Eric Katz of the Plenum Publishing, without whose interest and persistence this volume would not have been possible. v CONTENTS QUANTUM OPTICS: THEORY The Quantum Mechanics of Particles in Time-Dependent Quadrupole Fields Roy J. Glauber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Localization of Photons in Random and Quasiperiodic Media S. Dutta Gupta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Enhanced Fundamental Linewidth of a Laser Due to Outcoupling W. A. Hamel, M. P. van Exter, and J. P. Woerdman . . . . . . . . . . . . . . . . . . . . . . . ."

th The 29 International Conference was held as the first one of the millennium at its Fort Lauderdale venue. These conferences began, with High Energy Physics being the main topic, by introducing gradually cosmology into its programs. These proceedings of the 2000 conference reflect the variety of topics and ideas discussed. Our future conferences will be designed somewhat akin to the early Coral Gables Conferences where we shall seek some convergence of ideas. For this reason various committees have been formed from among the participating physicists. The committees and their memberships are listed in these proceedings. We further decided for the first time to include some graduate student participants in our future meetings for which also a committee has already been established. The topics will demonstrate a more activist structure of the Coral Gables Conferences, for example the duality of the gravitational forces and expansion of the universe will be discussed from this point of view since it conveys a convergence to the ideas of quintessence versus the ordinary theory, which are considered as the cause of the expansion of the universe. We further wish to announce that the future conferences will assume a collective organization where several committees as listed in these proceedings will have their input into the conference. We have now introduced new topics and ideas, which referred especially to the attractive and repulsive nature of the gravitational force. These proceedings of the conference contain a variety of topics and ideas.

Atomic Physics 7 presents the manuscripts of the invited talks delivered at the Seventh International Conference of Atomic Physics, held at M.I.T. August 4-8, 1980. This conference continues the tradition of the earlier conferences by reviewing broad areas of fundamental atomic physics and related subjects. In addition to the invited talks, one hundred and ninety contributed papers were presented in poster sessions. Abstracts of the contributed papers have been printed separately in a small volume. Three hundred and fifty participants from thirteen nations attended the conference. One of the highlights of the conference was an historical talk by Professor Abraham Pais of Rockefeller University entitled "The Birth of the Quantum Theory: Planck." The manuscript of this talk will be published elsewhere. Dr. John Bailey presented a talk on the proton-antiproton system at low energy, but was unable to provide a manuscript for this volume. Also omitted from these Proceedings, but one of the highlights of the Conference, are the comments by Professor I. I. Rabi, an active participant who chaired one session and spent an evening discussing science, history and public policy with graduate students at the Conference.

The Sixth International Conference on Atomic Masses was held in East Lansing, Michigan, Sept. 18-21, 1979. The conference was initiated, organized, and sponsored by the Commission on Atomic Masses and Fundamental Constants of the International Union of Pure and Applied Physics. The members of the conference committee are listed below: W. Benenson, Chairman Michigan State University R. C. Barber University of-Manitoba E. R. Cohen Rockwell International Institute of Chemical Physics, V. I. Goldanskii Moscow J. C. Hardy Chalk River, Canada W. H. Johnson University of Minnesota E. Kashy Michigan State University Orsay, France R. Klapisch J. A. Nolen, Jr. Michigan State University R. G. H. Robertson Michigan State University E. Roeckl G. S. I., Darmstadt B. N. Taylor National Bureau of Standards O. Schult IKF, Julich A. H. Wapstra IFO, Amsterdam N. Zeldes Racah Institute, Jerusalem The conference was a little different from the preceding one (in Paris, 1975) in that the fundamental constant aspects were limited to those directly related to atomic masses. The gap is to be filled by the second International Conference on Precision Measurement and Fundamental Constants which is now scheduled for June 1981 in Gaithersburg, Maryland. Only one of the seven sessions in this conference was devoted to fundamental constant determina tions. The conference was very strongly supported by the Department of Energy, the National Science Foundation, and the International Union of Pure and Applied Physics."

Dur previous volume 14 was devoted to an exposition of the topics of sensitivity analysis and uncertainty theory with its development and application in nuclear reactor physics at the heart of the discussion. In this volume, we return to our customary format as a selection of topics of current interest, authored by those working in the field. These topics range from the theoretical underpinnings of the (linear) Boltzmann transport equation to a resume of our ex pectations in what still may be thought of as twenty-first century technology, the world's fusion reactor program. In the first article of this volume, we have Protopop escu's analysis of the structure of the Boltzmann equation and its solutions for energy and space-dependent problems of an eigenvalue nature. There long has been a curious "folk history" effect in this area~ Wigner and Weinberg could de scribe it as "what was generally known was generally untrue". This account of the Boltzmann equation surely will show that a rigorous basis for our expectations of certain solutions can be well-founded on analysis. Ely Gelbard's review of the methods of determining diffusion-type parameters in complex geometries where simple diffusion theory would be welcome has required just as much rigor to determine how such modeling can be made accurate, although to a more immediate and practical purpose. The two articles can be seen as interesting contrasts, facets of the same underlying problem showing apparently different aspects of the same central core.

This volume presents five pedagogical articles spanning frontier developments in contemporary nuclear physics ranging from the physics of a single nucleon to nucleosynthesis in the Big Bang. Although the objectives of Advances in Nuclear Physics have been and will continue to be quite distinct from those of conventional conference proceedings, the articles in this volume are carefully edited and expanded manuscripts based on an outstanding series of lectures delivered at the VI J. A. Swieca Summer School in Brazil. Starting at the smallest scale, the first article by Dan Olof Riska addresses realistic chiral symmetric models of the nucleon. Since the analytic tools are not yet developed to solve nonperturbative QCD directly, significant effort has been devoted in recent years to the development of models which incorporate and are constrained by the approximate chiral symmetry manifested in QCD. This article provides a clear introduction to chiral symmetry and the Skyrme model, and discusses the Skyrme model's relation to the chiral bag model, its extensions, and its application to nucleons and hyperons.

The progress in nuclear magnetic resonance (NMR) spectroscopy that took place during the last several decades is observed in both experimental capabilities and theoretical approaches to study the spectral parameters. The scope of NMR spectroscopy for studying a large series of molecular problems has notably broadened. However, at the same time, it requires specialists to fully use its potentialities. This is a notorious problem and it is reflected in the current literature where this spectroscopy is typically only used in a routine way. Also, it is seldom used in several disciplines in which it could be a powerful tool to study many problems. The main aim of this book is to try to help reverse these trends.

This book is divided in three parts dealing with 1) high-resolution NMR parameters; 2) methods for understanding high-resolution NMR parameters; and 3) some experimental aspects of high-resolution NMR parameters for studying molecular structures. Each part is divided into chapters written by different specialists who use different methodologies in their work. In turn, each chapter is divided into sections. Some features of the different sections are highlighted: it is expected that part of the readership will be interested only in the basic aspects of some chapters, while other readers will be interested in deepening their understanding of the subject dealt with in them.
Shows how NMR parameters are useful for structure assignment as well as to obtain insight on electronic structuresEmphasis on conceptual aspects

Contributions by specialists who use the discussed methodologies in their everyday work

Review articles on three topics of considerable current interest make up the present volume. The first, on A-hypernuclei, was solicited by the editors in order to provide nuclear physicists with a general description of the most recent developments in a field which this audience has largely neglected or, perhaps, viewed as a novelty in which a bizarre nuclear system gave some information about the lambda-nuclear intersection. That view was never valid. The very recent developments reviewed here-particularly those pertaining to hypernuclear excitations and the strangeness exchange reactions-emphasize that this field provides important information about the models and central ideas of nuclear physics. The off-shell behavior of the nucleon-nucleon interaction is a topic which was at first received with some embarrassment, abuse, and neglect, but it has recently gained proper attention in many nuclear problems. Interest was first focused on it in nuclear many-body theory, but it threatened nuclear physicists'comfortable feeling about nonrelativistic potential theory, and many no doubt hoped that it would remain merely an esoteric diversion within the many-body cult. In the editors' opinion, this subject is now emi nently respectable and a review of it indeed timely. The third topic, nuclear charge distributions, is one which almost every nuclear physicist believed had been weIl in hand for some years."

The 1979 Cargese Summer Institute on Quarks and Leptons was organized by the Universite Pierre et Marie Curie, Paris (M. LEVY and J.-L. BASDEVANT), CERN (M. JACOB), the Universite Catholi~ue de Louvain (D. SPEISER and J. WEYERS), and the Katholieke Universiteit te Leuven (R. GASTMANS), who, like in 1975 and 1977, had joined their efforts and worked in common. It was the 20th Summer Institute held at Cargese and the 5th one organized by the two institutes of theoretical physics at Leuven and Louvain-la- Neuve. This time, the school was dominated by the impressive advances which were made in the field of perturbative ~uantum chromodyna- mics and its applications to high energy phenomena involving strongly interacting particles. The unification of weak and electromagnetic interactions being well established, a new picture in particle physics emerges wherein a possible unification of weak, electromagnetic, and strong forces is put forward. Its conse~uences were also discussed in detail. Finally, to complete the picture of the present status of high energy physics, experi- mentalists from the major laboratories around the world reported on the latest developments in electron-positron scattering, neutrino induced reactions, and hadron collisions. We owe many thanks to all those who have made this Summer Institute possible! Thanks are due to the Scientific Committee of NATO and its President for a generous grant and especially to the head of the Scientific Affairs Division, Dr. M. DI LULLO for his constant help and encouragements.

The Editors take pleasure in presenting Volume 13 of this annual review series, consisting, as usual, of author itative reviews of timely developments in the technical fields of nuclear engineering, science, and teechnology. No one in the community we try to serve in a post Harrisburg era will need convincing of the relevance of the first two items to be mentioned from the volume. Instru mentation for two-phase flow measurements, by Banerjee and Lahey, has applicability in the engineering research labor atory and to power reactors; the U. S. LWR still remains the dominant power reactor type and seems likely to retain its hold if only through the capital of existing plants this century. Messrs. Bohm, Closs, and Kuhn, however, have a longer time scale to respect as they view for us the prospects of nuclear waste disposal from a European viewpoint. They bring out nicely the political aspects that cannot be divorced from technical considerations in this area, or in the more militant terms of confrontation, in this arena, perhaps. We are pleased to carry in this volume two complemen tary papers on mathematical methods in nuclear engineering."