Computational methods have become an indispensible tool for elucidating the mechanism of organometallic reactions. This snapshot of state-of-the-art computational studies provides an overview of the vast field of computational organometallic chemistry. Authors from Asia, Europe and the US have been selected to contribute a chapter on their specialist areas. Topics addressed include: DFT studies on zirconium-mediated reactions, force field methods in organometallic chemistry, hydrogenation of -systems, oxidative functionalization of unactivated C-H bonds and olefins, the osmylation reaction, and cobalt carbonyl clusters. The breadth and depth of the contributions demonstrate not only the crucial role that computational methods play in the study of a wide range of organometallic reactions, but also attest the robust health of the field, which continues to benefit from, as well as inspire novel experimental studies.

Since the inception of this volume, the world's nancial climate has radically changed. Theemphasishasshiftedfromboomingeconomiesandeconomicgrowth totherealityofrecessionanddiminishingoutlook. Witheconomicdownturncomes opportunity,inallareasofchemistryfromresearchanddevelopmentthroughto productregistrationandriskassessment,replacementsarebeingsoughtforcostly time-consumingprocesses. Leadingamongstthereplacementsaremodelswithtrue predictivecapability. Ofthesecomputationalmodelsarepreferred. This volume addresses a broad need within various areas of the "chemical industries", from pharmaceuticals and pesticides to personal products to provide computationalmethodstopredicttheeffects,activitiesandpropertiesofmolecules. Itaddressestheuseofmodelstodesignnewmoleculesandassesstheirfateand effectsbothtotheenvironmentandtohumanhealth. Thereisanemphasisrunning throughoutthisvolumetoproducerobustmodelssuitableforpurpose. Thevolume aimstoallowthereaderto nddataanddescriptorsanddevelop,discoverandutilise validmodels. Gdansk, ' Poland TomaszPuzyn Jackson,MS,USA JerzyLeszczynski Liverpool,UK MarkT. D. Cronin May2009 CONTENTS Part I Theory of QSAR 1 QuantitativeStructure-ActivityRelationships(QSARs)- ApplicationsandMethodology...3 Mark T. D. Cronin 1. 1. Introduction...3 1. 2. PurposeofQSAR...4 1. 3. ApplicationsofQSAR...4 1. 4. Methods...5 1. 5. TheCornerstonesofSuccessfulPredictiveModels ...7 1. 6. AValidated(Q)SARoraValidPrediction? ...9 1. 7. UsinginSilicoTechniques ...9 1. 8. NewAreasforinSilicoModels...11 1. 9. Conclusions...11 References ...11 2 TheUseofQuantumMechanicsDerivedDescriptorsin ComputationalToxicology...13 Steven J. Enoch 2. 1. Introduction...13 2. 2. TheSchrodingerEquation...15 2. 3. Hartree-FockTheory...17 2. 4. Semi-EmpiricalMethods:AM1andRM1...18 2. 5. ABInitio:DensityFunctionalTheory...19 2. 6. QSARforNon-ReactiveMechanismsofAcute(Aquatic) Toxicity...19 2. 7. QSARsforReactiveToxicityMechanisms...21 2. 7. 1. AquaticToxicityandSkinSensitisation...21 2. 7. 2. QSARsforMutagenicity ...24 2. 8. FutureDirectionsandOutlook...25 2. 9. Conclusions...26 References ...26 vii viii Contents 3 MolecularDescriptors...29 Viviana Consonni and Roberto Todeschini 3. 1. Introduction...29 3. 1. 1. De nitions...29 3. 1. 2. History...31 3. 1. 3. Theoreticalvs. ExperimentalDescriptors...33 3. 2. MolecularRepresentation ...35 3. 3. TopologicalIndexes...38 3. 3. 1. MolecularGraphs...38 3. 3. 2. De nitionandCalculationofTopologicalIndexes(TIs) 39 3. 3. 3. Graph-TheoreticalMatrixes...42 3. 3. 4. ConnectivityIndexes ...48 3. 3. 5. CharacteristicPolynomial ...50 3. 3. 6. SpectralIndexes ...53 3. 4. AutocorrelationDescriptors ...

Special numerical techniques are already needed to deal with nxn matrices for large n.Tensor data are of size nxnx...xn=n DEGREESd, where n DEGREESd exceeds the computer memory by far. They appear for problems of high spatial dimensions. Since standard methods fail, a particular tensor calculus is needed to treat such problems. The monograph describes the methods how tensors can be practically treated and how numerical operations can be performed. Applications are problems from quantum chemistry, approximation of multivariate functions, solution of pde, e.g., with stochastic coefficie

Trends in Computational Nanomechanics reviews recent advances in analytical and computational modeling frameworks to describe the mechanics of materials on scales ranging from the atomistic, through the microstructure or transitional, and up to the continuum. The book presents new approaches in the theory of nanosystems, recent developments in theoretical and computational methods for studying problems in which multiple length and/or time scales must be simultaneously resolved, as well as example applications in nanomechanics.

This title will be a useful tool of reference for professionals, graduates and undergraduates interested in Computational Chemistry and Physics, Materials Science, Nanotechnology.

In 1931 Vrey, Brickwedde, and Murphy discovered the hydrogen isotope deuterium. The isotopic enrichment was found to arise from the fact that the electrolysis oflight water is faster than of heavy water [1,2]. This success showed that although different isotopes of an element behave identically from a chemical standpoint the different isotopic masses nevertheless lead to both isotope effects on equilibrium as well as on rate constants of chemical reactions. Soon, ratios of equilibrium constants of isotopic reactions were called "equilibrium isotope effects" (EIE), ratios of isotopic rate constants "kinetic isotope effects" (KIE). Isotope effects have been found to be especially large for those elements which are directly involved in bond breaking and bond formation during the reaction studied [3]. Such effects are, therefore, referred to as "primary". Isotopic substitution in atomic sites which maintain all chemical bonds with their neighbors during the reaction of interest leads then only to smaller "secondary" isotope effects. Because of the unique mass relation between the different hydrogen isotopes hydrogen/deuterium isotope effects are particularly large and have attracted most attention. The largest contributions to these effects arise from changes in the vibrational frequencies of the reactants. The theory of equilibrium isotope effects has been founded by Vrey [4] and Bigeleisen [5,6] and has widely been accepted [3].

A researcher trying to predict or interpret spectra of transition metal ionsin possible laser host materials is confronted with a variety of different methods of describing the same physical situation. This book provides a systematic approach to the applied theory of crystal-field interactions of transition metal ions in 49 crystalline hosts that are or show promise of being good laser materials. The tables that make up the main part of the book present the experimentally determined parameters of the 3dN, 4dN, and 5dN transition-metal ions in the second, third, and fourth ionization states. These parameters have been converted to Slater and crystal-field parameters. The book is a source for research workers in laser development and in crystal-field theory, and for graduate students of solid state chemistry and physics.

Bruce Yoder's thesis outlines his investigation of the dissociative chemisorption of methane (CH4) on a nickel single crystal. In this work Bruce uses a molecular beam and infrared laser techniques to prepare methane in excited rovibrational states. The excited methane molecules are aligned relative to the target nickel surface. Bruce describes the discovery and exploration of a previously unknown steric effect in the dissociation reaction between a vibrationally excited methane molecule and a nickel crystal. From these studies we see that methane molecules are up to twice as reactive when the vibration is aligned parallel rather than perpendicular to the surface. This discovery will help guide the development of detailed predictive models of methane chemisorption, which in turn may lead to better catalysts for the synthesis of several industrially relevant chemicals, including hydrogen fuel from natural gas.

In 1989, the Swiss Society for Optics and Electron Microscopy (Schweizerische Gesellschaft fOr Optik und Elektronenmikroskopie - Societe Suisse d'Optique et de Microscopie Electronique), formerly founded as "Schweizerisches Komitee fOr Optik -Comite Suisse d'Optique" could celebrate its 40th anniversary. Already during and mainly just after World War II the then newly invented electron microscopy was introduced also in Switzerland and its importance quickly increased. In 1955, our Society was split into two sections, i.e. for Optics and for Electron Microscopy, both with their own secretaries. Other foreign Societies for electron microscopy in Europe and all over the world have celebrated their anniversaries in the last few years and held reviews at these occasions. In view of this and facing the fact that many of the pioneers and founders of our Society might help to record the history of electron microscopy in our country, the board of SGOEM-SSOME has decided to have a short review of its history written and published. This short review has now developed into a book. viii I would like to thank here all the authors, who have contributed to this volume very much. My special thanks go to Prof. Dr.John R. GOnter, without whose circumspective and energetic work this review of the history of electron microscopy in Switzerland would never have appeared.

Any description of the workings of nature by means of measurements and ob servations is beset with the problem of how to cope with an immense amount of information. In physics, it is an established approach to derive basic equations which then serve as cornerstones of what is called a theory of the phenomena. This derivation is based on certain characteristics of the phenomena, the refine ment of which results from a reduction of the amount of empirical information, with the reduction leading to an enhancement of the very characteristics that are sought for in the otherwise seemingly amorphous wealth of data. If physics is mainly concerned with the derivation of equations, lately there has emerged a conceptually different approach, which in a way is equivalent to a reversal of the line of attack: here, the basic equations serve as the point of departure and the aim is to demonstrate that the equations are capable of de to represent the essence of the scribing certain characteristics which are thought phenomenon under investigation. By definition, this variant approach must tran scend the realm of pure physics and could possibly be termed "applied mathe matics" in a broader sense. The phenomena it strives to characterize arise from a range of influences such that a combination of theoretical concepts from physics, chemistry, engineering, biology, etc. , is called for.

Monte Carlo computer simulations are now a standard tool in scientific fields such as condensed-matter physics, including surface-physics and applied-physics problems (metallurgy, diffusion, and segregation, etc. ), chemical physics, including studies of solutions, chemical reactions, polymer statistics, etc., and field theory. With the increasing ability of this method to deal with quantum-mechanical problems such as quantum spin systems or many-fermion problems, it will become useful for other questions in the fields of elementary-particle and nuclear physics as well. The large number of recent publications dealing either with applications or further development of some aspects of this method is a clear indication that the scientific community has realized the power and versatility of Monte Carlo simula tions, as well as of related simulation techniques such as "molecular dynamics" and "Langevin dynamics," which are only briefly mentioned in the present book. With the increasing availability of recent very-high-speed general-purpose computers, many problems become tractable which have so far escaped satisfactory treatment due to prac tical limitations (too small systems had to be chosen, or too short averaging times had to be used). While this approach is admittedly rather expensive, two cheaper alternatives have become available, too: (i) array or vector processors specifical ly suited for wide classes of simulation purposes; (ii) special purpose processors, which are built for a more specific class of problems or, in the extreme case, for the simulation of one single model system."

First-Principles-Based Multiscale, Multiparadigm Molecular Mechanics and Dynamics Methods for Describing Complex Chemical Processes, by A. Jaramillo-Botero, R. Nielsen, R. Abrol, J. Su, T. Pascal, J. Mueller and W. A. Goddard.- Dynamic QM/MM: A Hybrid Approach to Simulating Gas Liquid Interactions, by S. Yockel and G. C. Schatz.- Multiscale Modelling in Computational Heterogeneous Catalysis, by F. J. Keil.- Real-World Predictions from Ab Initio Molecular Dynamics Simulations, by B. Kirchner, P. J. di Dio and J. Hutter.- Nanoscale Wetting Under Electric Field from Molecular Simulations, by C. D. Daub, D. Bratko and A. Luzar.- Molecular Simulations of Retention in Chromatographic Systems: Use of Biased Monte Carlo Techniques to Access Multiple Time and Length Scales, by J. L. Rafferty, J. I. Siepmann, M. R. Schure.- Thermodynamic Properties for Applications in Chemical Industry via Classical Force Fields, by G. Guevara-Carrion, H. Hasse and J. Vrabec.- Multiscale Approaches and Perspectives to Modeling Aqueous Electrolytes and Polyelectrolytes, by L. Delle Site, C. Holm and N. F. A. van der Vegt.- Coarse-Grained Modeling for Macromolecular Chemistry, by H. A. Karimi-Varzaneh and F. Muller-Plathe.-"

This fourth edition contains a few additional figures. Otherwise only typographical er rors have been removed. The final chapter on Fundamentals of the Quantum Theory of Chemical Bonding is continued in an extended way in the textbook Molecular Physics and Elements of Quantum Chemistry by the same authors. This book contains, in particular, a profound presentation of group theory as applied to atoms and molecules. Furthermore, the in teraction between atoms and molecules and light is treated in detail. We thank again Springer-Verlag, in particular Dr. H.1. Kblsch and Mr. C.-D. Bachem for their excellent cooperation as always, and Prof. W. D. Brewer for his con tinuous support in translating our German text. Stuttgart, February 1994 H. Haken H. C. Wolf Preface to the Third Edition The second edition of this book again enjoyed a very positive reception from both uni versity teachers and students. In this edition we have removed all of the typographical errors that came to our attention. In order to keep the book as current as possible, new developments in the direct observation of individual atoms in electromagnetic traps (Paul traps) and of atoms in molecules on solid surfaces using the scanning tunnel microscope have been added to this edition.

For more than 100 years the Beilstein Handbook has been publishing checked and evaluated data on organic compounds. It has become the major reference book for the chemical and physical properties of organic com pounds. The prediction of these physical properties was the subject of the Beilstein workshop. The ability to predict physical properties is for several reasons of great interest to the Beilstein Institute. It is of primary importance to be able to check the abstracted data for accuracy and to eliminate simple mistakes like typing errors. Presently all the work whether manuscript writing or evaluation of data is carried out manually. This is very time consuming, with the entry of Beilstein into electronic data gathering and publication, the opportunity for computerized consistency checking has become available. Contrary to belief, when one examines the Beilstein Handbook or Chemical Abstracts there is a dearth of chemical information. There are a great many compounds but few are well defined resulting in large gaps in the information available to the chemist. These information gaps could be filled by using algorithmic methods to estimate the properties of interest. An important question to answer is "What is the chemist's reaction to estimated data?" Will he accept it for use, within limits defined by the method, or will it be unacceptable and therefore detrimental for the data base. However if one could partly fill gaps in the data base the increase in the power of the search techniques would be marked."

There have been many significant advances in time-dependent density functional theory over recent years, both in enlightening the fundamental theoretical basis of the theory, as well as in computational algorithms and applications. This book, as successor to the highly successful volume Time-Dependent Density Functional Theory (Lect. Notes Phys. 706, 2006) brings together for the first time all recent developments in a systematic and coherent way.

First, a thorough pedagogical presentation of the fundamental theory is given, clarifying aspects of the original proofs and theorems, as well as presenting fresh developments that extend the theory into new realms-such as alternative proofs of the original Runge-Gross theorem, open quantum systems, and dispersion forces to name but a few. Next, all of the basic concepts are introduced sequentially and building in complexity, eventually reaching the level of open problems of interest. Contemporary applications of the theory are discussed, from real-time coupled-electron-ion dynamics, to excited-state dynamics and molecular transport. Last but not least, the authors introduce and review recent advances in computational implementation, including massively parallel architectures and graphical processing units. Special care has been taken in editing this volume as a multi-author textbook, following a coherent line of thought, and making all the relevant connections between chapters and concepts consistent throughout. As such it will prove to be the text of reference in this field, both for beginners as well as expert researchers and lecturers teaching advanced quantum mechanical methods to model complex physical systems, from molecules to nanostructures, from biocomplexes to surfaces, solids and liquids.

"From the reviews of LNP 706: "

"This is a well structured text, with a common set of notations and a single comprehensive and up-to-date list of references, rather than just a compilation of research articles. Because of its clear organization, the book can be used by novices (basic knowledge of ground-state DFT is assumed) and experienced users of TD-DFT, as well as developers in the field." (Anna I. Krylov, Journal of the American Chemical Society, Vol. 129 (21), 2007)

"This book is a treasure of knowledge and I highly recommend it. Although it is a compilation of chapters written by many different leading researchers involved in development and application of TDDFT, the contributors have taken great care to make sure the book is pedagogically sound and the chapters complement each other ...]. It is highly accessible to any graduate student of chemistry or physics with a solid grounding in many-particle quantum mechanics, wishing to understand both the fundamental theory as well as the exponentially growing number of applications. ...] In any case, no matter what your background is, it is a must-read and an excellent reference to have on your shelf."

Amazon.com, October 15, 2008, David Tempel (Cambridge, MA)"

In a way the MOTECC-89 project started in the early sixties at the IBM Research Laboratory in San Jose, California. The six years of post-doctoral research, first with Giulio Natta on conductive polymers, with Michael Kasha on spin-orbit effects, with Kenneth S. Pitzer on high temperature molecules and thermo dynamics and with R. S. Mulliken in the quantum chemistry of small molecules had demonstrated pragmatically the importance of a broad-based research and also let me taste some of the excitement to be derived from interdisciplinarity. Thus when I started to gather a department in the newly opened IBM Research Laboratory in San Jose, California, I purposely named it "Large Scale Scientific Computation Department," avoiding reference to chemistry, physics, statistical mechanics or fluid dynamics, which were our main tasks. In the sixties interdisciplinarity was more and more recognized as a most important if not nec essary avenue to cope with the technical needs of our society. However, at that time interdisciplinarity was synonymous with "team work," and true interdisciplinarity was a formidably difficult objective. Although I headed an excellent group of scientists with different backgrounds and there was much progress and creativity, still each one of us was more or less conducting his own research in his own field with occasional cross-field partnerships and with some of the computational techniques as our common base. Later, in 1974, I made a second attempt, this time starting a new department at the Donegani Institute, Montedison, in Novara, Italy."

Prof. Baev presents in his book the development of the thermodynamic theory of specific intermolecular interactions for a wide spectrum of organic compounds: ethers, ketones, alcohols, carboxylic acids, and hydrocarbons. The fundamentals of an unconventional approach to the theory of H-bonding and specific interactions are formulated based on a concept of pentacoordinate carbon atoms. New types of hydrogen bonds and specific interactions are substantiated and on the basis of the developed methodology their energies are determined. The system of interconnected quantitative characteristics of the stability of specific intermolecular interactions is presented. The laws of their transformations are discussed and summarized. The new concept of the extra stabilizing effect of isomeric methyl groups on the structure and stability of organic molecules is introduced and the destabilization action on specific interactions is outlined.

Strutural Analysis of Point Defects in Solids introduces the principles and techniques of modern electron paramagnetic resonance (EPR) spectroscopy essentialfor applications to the determination of microscopic defect structures. Investigations of the microscopic and electronic structure, and also correlations with the magnetic propertiesof solids, require various multiple magnetic resonance methods, such as ENDOR and optically detected EPR or ENDOR. This book discusses experimental, technological and theoretical aspects of these techniques comprehensively, from a practical viewpoint, with many illustrative examples taken from semiconductors and other solids. The nonspecialist is informed about the potential of the different methods, while the researcher faced with the task of determining defect structures isprovided with the necessary tools, together with much information on computer-aided methods of data analysis and the principles of modern spectrometer design.

The first edition of this book was published in 1978 and a new Spanish e(, tition in 1989. When the first edition appeared, Professor A. Martin suggested that an English translation would meet with interest. Together with Professor A. S. Wightman, he tried to convince an American publisher to translate the book. Financial problems made this impossible. Later on, Professors E. H. Lieband W. Thirring proposed to entrust Springer-Verlag with the translation of our book, and Professor W. BeiglbOck accepted the plan. We are deeply grateful to all of them, since without their interest and enthusiasm this book would not have been translated. In the twelve years that have passed since the first edition was published, beautiful experiments confirming some of the basic principles of quantum me chanics have been carried out, and the theory has been enriched with new, im portant developments. Due reference to all of this has been paid in this English edition, which implies that modifications have been made to several parts of the book. Instances of these modifications are, on the one hand, the neutron interfer ometry experiments on wave-particle duality and the 27r rotation for fermions, and the crucial experiments of Aspect et al. with laser technology on Bell's inequalities, and, on the other hand, some recent results on level ordering in central potentials, new techniques in the analysis of anharmonic oscillators, and perturbative expansions for the Stark and Zeeman effects."

Mechanism of charge transport in organic solids has been an issue of intensive interests and debates for over 50 years, not only because of the applications in printing electronics, but also because of the great challenges in understanding the electronic processes in complex systems. With the fast developments of both electronic structure theory and the computational technology, the dream of predicting the charge mobility is now gradually becoming a reality. This volume describes recent progresses in Prof. Shuai's group in developing computational tools to assess the intrinsic carrier mobility for organic and carbon materials at the first-principles level. According to the electron-phonon coupling strength, the charge transport mechanism is classified into three different categories, namely, the localized hopping model, the extended band model, and the polaron model. For each of them, a corresponding theoretical approach is developed and implemented into typical examples.

This volume contains papers presented at the Thirteenth Taniguchi Symposium on the Theory of Condensed Matter, which was held at Kashikojima (in Ise Shima National Park), Japan, from 6th to 9th November, 1990. The topic of the symposium was Molecular Dynamics Simulations. The general objective of this series of the Taniguchi Symposia is to encour age developing fields of great promise in condensed matter physics. Our theme, molecular dynamics (MD) simulations, certainly fulfills this requirement, be cause the field is developing at a remarkable pace and its future is considered almost boundless. It was in the 1950s that the original idea of the MD methods was first pro posed and applied to the study of physical systems composed of many particles. In fact, the invention of the MD techniques occurred soon after the construction of the first computers. For almost 35 years since then, MD methods, together with Monte Carlo methods, have played major parts in the drama of computer simulations. The triumph of MD simulations is not confined to numerical aspects of detailed analyses of physical systems. MD simulations have verified some un expected facts and introduced some new concepts, all of which had never been predicted previously from analytical theories. The occurrence of the Alder tran sition in a system of repulsive particles and the behavior of the long-time tails of the velocity autocorrelation function for a liquid are just two examples of the results achieved by means of MD studies."

Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment ofall branches by one author, or even by several, becomes increasingly difficult. by experts workinginvarious This seriesis planned to present articles written fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work. Its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Computer Assistance in the Analysis of High-Resolution NMR Spectra P. DIEHL and H. KELLERHALS Departmentof Physics, University ofBasle, Switzerland E. LUSTIG Food and Drug Administration, Washington, D.C., U.S.A.

Les hypotheses, n'en deplaise a mon contradicteur, sont l'ame des progres de la science. Louis Pasteur The concept of chirality, established 100 years ago, plays an im- portant role in almost all domains and dimensions of our recent scientific view of life. Chiral properties can be found in fundamen- tal nuclear particles, in molecules, and in the macroscopic world of living nature (plants and animals) and inanimate nature (crystals). In particular, chirality, or more precisely chiral excess, is evident in human beings. For example, the expected symmetry of the hands turns out to be functionally non-existent. Consequently chirality occurs in the technical sphere, where screws are the best-known examples, since most of them are made for right-handed people. Chirality is not confined to static objects but influences processes such as chemical reactions. The occurrence of chiral objects on different dimensional scales has been treated in the past in mutually independent frameworks. There were, however, two remarkable events from which the conclu- sion can be drawn that the appearance of chirality in various fields has a common cause. On the one hand, physicists found evidence that the well-known biomolecular homochirality can be traced back to the chirality of weak bosons. At the same time, on the other hand, the so-called thalidomide tragedy occurred when thalido- mide molecules of a certain chirality, taken by pregnant women, caused deformed children.

Plasma Spectroscopy systematically develops the foundations of spectroscopy for plasmas subjected to quasi-monochromatic electric fields in the microwave or visible range. Such fields may be due to longitudinal Langmuir waves or low hybrid oscillations, which are excited in pulsed discharged or by high-current beams of charged particles. Even more important are the transverse fields present in the plasmas of tokamaks, laser fusion, and technological microwave discharges. This book is intended for researchers dealing with plasma spectroscopy, plasma diagnostics, high frequency and microwave discharges, laser induced discharges, particle and laser-beam interactions with plasmas, controlled fusion, and ionospheric and astrophysical plasmas. It describes methods for measuring the field and plasma parameters and discusses their practical application. It also presents new results on nonpertubative analysis of the interaction of quantum systems with a strong radiation field.

In recent years there has been growing interest in the nucleon-nucleon correl ations inside nuclei. In many respects the motions of the nucleons can be very well described by an overall mean field, so that the motion of each nucleon is governed by the mean field due to all the other nucleons. This concept underlies the Fermi-gas, Hartree-Fock and shell models and has enabled a range of nuclear properties to be calculated, often to surprising accuracy. It gradually became clear, however, that these mean-field models are limited by the effects due to the very strong interactions between the nucleons that occur at short distances; these are the short-range correlations. They are responsible for instance for the high-momentum components in the nucleon momentum dis tribution, and prevent the simultaneous description of the nuclear density and momentum distributions by the same mean field. It thus becomes necessary to develop methods for including the effects of nucleon correlations in nuclei, and these are the main subject of this book. Some related problems of nuclear structure were discussed in an earlier book by the same authors: Nucleon Momentum and Density Distributions in Nuclei (Clarendon Press, Oxford, 1988). The main aim of that book was to study the effects of nucleon-nucleon correlations, both short-range and tensor, on the nucleon momentum distribution, which is particularly sensitive to these correl ations, and on the nucleon density distribution."

Modern Methods of Plant Analysis When the handbook Modern Methods of Plant Analysis was first introduced in 1954 the considerations were: 1. the dependence of scientific progress in biology on the improvement of existing and the introduction of new methods; 2. the difficulty in finding many new analytical methods in specialized journals which are normally not accessible to experimental plant biologists; 3. the fact that in the methods sections of papers the description of methods is frequently so compact, or even sometimes so incomplete that it is difficult to reproduce experiments. These considerations still stand today. The series was highly successful, seven volumes appearing between 1956 and 1964. Since there is still today a demand for the old series, the publisher has decided to resume publication of Modern Methods of Plant Analysis. It is hoped that the New Series will be just as acceptable to those working in plant sciences and related fields as the early volumes undoubtedly were. It is difficult to single out the major reasons for success of any publication, but we believe that the methods published in the first series were up-to-date at the time and presented in a way that made description, as applied to plant material, complete in itself with little need to consult other publications. Contributing authors have attempted to follow these guidelines in this New Series of volumes.