The liquid crystalline state may be identified as a distinct and unique state of matter which is characterised by properties which resemble those of both solids and liquids. It was first recognised in the middle of the last century through the study of nerve myelin and derivatives of cholesterol. The research in the area really gathered momentum, however, when as a result of the pioneering work of Gray in the early 1970's organic compounds exhibiting liquid crystalline properties were shown to be suitable to form the basis of display devices in the electronic products. The study of liquid crystals is truly multidisciplinary and has attached the attention of physicists, biologists, chemists, mathematicians and electronics engineers. It is therefore impossible to cover all these aspects fully in two small volumes and therefore it was decided in view of the overall title of the series to concentrate on the structural and bonding aspects of the subject. The Chapters presented in these two volumes have been organised to cover the following fundamental aspects of the subiect. The calculation of the structures of liquid crystals, an account of their dynamical properties and a discussion of computer simulations of liquid crystalline phases formed by Gay Berne mesogens. The relationships between molecular conformation and packing are analysed in some detail. The crystal structures of liquid crystal mesogens and the importance of their X ray scattering properties for characterisational purposes are discussed.

This book presents the most comprehensive analysis of bonding in polyoxometalates and related oxides based on classical bonding concepts and the bond valence model. Numerous tables and figures underline and illuminate the results, making it a valuable resource.

The French chemist Marcelin Berthelot put forward a classical and by now an often cited sentence revealing the quintessence of the chemical science: "La Chimie cree son objet." This is certainly true because the largest number of molecular compounds were and are continuously synthesized by chemists themselves. However, modern computational quantum chemistry has reached a state of maturity that one can safely say: "La Chimie Theorique cree son objet" as well. Indeed, modern theoretical chemistry is able today to provide reliable results on elusive systems such as short living species, reactive intermediates and molecules which will perhaps never be synthesized because of one or another type of instability. It is capable of yielding precious information on the nature of the transition states, reaction paths etc. Additionally, computational chemistry gives some details of the electronic and geometric structure of molecules which remain hidden in experimental examinations. Hence, it follows that powerful numerical techniques have substantially enlarged the domain of classical chemistry. On the other hand, interpretive quantum chemistry has provided a conceptual framework which enabled rationalization and understanding of the precise data offered either by experiment or theory. It is modelling which gives a penetrating insight into the chemical phenomena and provides order in raw experimental results which would otherwise represent just a large catalogue of unrelated facts.

In this text the authors develop quantum dynamics of open systems for a wide class of irreversible processes starting from the concept of completely positive semigroups. This unified approach makes the material easily accessible to non-specialists and provides an easy access to practical applications. Written for graduate students, the book presents a wealth of useful examples; in particular, models of unstable and N-level systems are treated systematically and in considerable detail including new types of generated Bloch-equations. The general theory is extensively summarized from abstract dynamical maps to those obtained by a reduction of Hamiltonian dynamics under a Markovian approximation. Various methods of determining semigroup generators and the corresponding master equations are discussed including time-dependent and nonlinear generators. Further topics treated are a generalized H-theorem, quantum detailed balance and return to equilibrium, discrete quantum Boltzmann equation, nonlinear Schrodinger equation, spin relaxation by spin waves, entropy production and its generalization by a measure of irreversibiblity."

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.

In 1965 a book by P. Bartlett appeared under the title "The Nonclassical Ions" 1). The book is a collection of papers reprinted from various journals. The many reviews that have appeared since 2-22) are either antiquated (the book published in 1972 12) covers the literature mainly before 1968) or relatively biased (e.g., 3.4,10" on brief 2, 7,11). This review attempts to discuss the various points of view on the "nonclassical" carbocations. The main point is to establish the relative role of "nonclassical" and "classical" ions in various chemical processes. The author has followed P. Bartlett's advice 1) that when setting forth the achievements of the human mind one should see how we came to the modern understanding of a given problem (" ... how we know what we know"). The theory of "nonclassical" ions offers an explanation of many unique chemical, stereochemical and kinetic peculiarities of bicyclic compounds. It has expanded our knowledge on chemical bonds in carbocations by introducing electron-deficient bonds (as in boron hydrides). It has accounted for many rearrangements of stable cations. As a "side" result our knowledge has been extended about ionization processes in a solution, as well as about stereochemical methods. 2 Main Terms of Nonclassical Carbocations In 1939 Hevell, Salas and Wilson 23) assumed an intermediate, "bridge" ion 2 to be formed when camphene hydrochloride 1 is rearranged into isobornyl chloride 3. This happened 17 years after Meerwein first postulated the intermediate formation of "carbonium" ions in chemical reactions.

Over the past 40 years, Rotational Isomeric State (RIS) models for hundreds of polymer structures have been developed. The RIS approach is now available in several software packages. The user is often faced with the time-consuming task of finding appropriate RIS parameters from the literature. This book aims at easing this step by providing a comprehensive overview of the models available. It reviews the literature from the first applications of RIS models to the end of 1994, comprises synthetic as well as naturally orccuring macromolecules, and tabulates all the pertinent features of published models. It will help readers, even when not very familiar with the method, to take advantage of this computationally efficient way of assessing the conformational properties of macromolecular systems.

1. R.G. Pearson Chemical Hardness - An Historical Introduction 2. P.K. Chattaraj Density Functional Theory of Chemical Hardness 3. J.L. Gazqu z Hardness and Softness in Density Functional Theory 4. L. Komorowski Hardness Indices for Free and Bonded Atoms 5. N.H. March The Ground-State Energy of Atomic and Molecular Ions and Its Variation with the Number of Elections 6. K. Sen Isoelectronic Changes in energy, Electronegativity, and Hardness in Atoms via the Calculations of 7. P. Politzer, J.S. Murray, M.E. Grice Charge Capacities and Shell Structures of Atoms 8. R. F. Nalewajski The Hardness Based Molecular Charge Sensitivities and Their Use in the Theory of Chemical Reactivity 9. B.G. Baekelandt, R. A. Schoonheydt, W.J. Mortier The EEM Approach to Chemical Hardness in Molecules and Solids: Fundamentals and Applications 10. J.A. Alonso, L. C. Balbas Hardness of Metallic Clusters

1. R. Carlson, A. Nordahl: Exploring Organic Synthetic Experimental Procedures 2. S.J. Cyvin, B.N. Cyvin, J. Brunvoll: Enumeration of Benzenoid Chemical Isomers with a Study of Constant-Isomer Series 3. E.Hladka, J. Koca, M. Kratochvil, V. Kvasnicka, L. Matyska, J. Pospichal, V. Potucek: The Synthon Model and the Program PEGAS for Computer AssistedOrganic Synthesis 4. K. Bley, B. Gruber, M. Knauer, N. Stein, I. Ugi: New Elements in the Representation of the Logical Structure of Chemistry byQualitative Mathematical Models and Corresponding Data Structures

Printed Organic And Molecular Electronics was compiled to create a reference that included existing knowledge from the most renowned industry, academic, and government experts in the fields of organic semiconductor technology, graphic arts printing, micro-contact printing, and molecular electronics. It is divided into sections that consist of the most critical topics required for one to develop a strong understanding of the states of these technologies and the paths for taking them from R&D to the hands of consumers on a massive scale. As such, the book provides both theory as well as technology development results and trends.

Structure, Bonding, and Reactivity of Reactant Complexes and Key Intermediates, by Elena Soriano and Jose Marco-Contelles.-

Cycloisomerization of 1, "n"-Enynes Via Carbophilic Activation, by Patrick Yves Toullec and Veronique Michelet.-

DFT-Based Mechanistic Insights into Noble Metal-Catalyzed Rearrangement of Propargylic Derivatives: Chirality Transfer Processes, by Olalla Nieto Faza and Angel R. de Lera.-

"N"-Heterocyclic Carbene Complexes of Au, Pd, and Pt as Effective Catalysts in Organic Synthesis, by Andrea Correa, Steven P. Nolan and Luigi Cavallo.-

Activation of Allenes by Gold Complexes: A Theoretical Standpoint, by Max Malacria, Louis Fensterbank and Vincent Gandon.-

Heterocyclization of Allenes Catalyzed by Late Transition Metals: Mechanisms and Regioselectivity, by Benito Alcaide, Pedro Almendros, Teresa Martinez del Campo, Elena Soriano and Jose Marco-Contelles.-

Gold-Catalyzed Cycloadditions Involving Allenes: Mechanistic Insights from Theoretical Studies, by Sergi Montserrat, Gregori Ujaque, Fernando Lopez, Jose L. Mascarenas and Agusti Lledos.-

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When, forty years ago, as a student of Charles Coulson in Oxford I began work in theoretical chemistry, I was provided with a Brunsviga calculator-a small mechanical device with a handle for propulsion, metal levers for setting the numbers, and a bell that rang to indicate overflow. What has since come to be known as computational chemistry was just beginning. There followed a long period in which the fundamental theory of the "golden age" (1925-1935) was extended and refined and in which the dreams of the early practitioners were gradually turned into hard arithmetic reality. As a still-computing survivor from the early postwar days now enjoying the benefits of unbelievably improved hardware, I am glad to contribute a foreword to this series and to have the opportunity of providing a little historical perspective. After the Brunsviga came the electromechanical machines of the late 1940s and early 1950s, and a great reduction in the burden of calculating molecular wavefunctions. We were now happy. At least for systems con taining a few electrons it was possible to make fully ab initio calculations, even though semiempirical models remained indispensable for most molecules of everyday interest. The 1950 papers of Hall and of Roothaan represented an important milestone along the road to larger-scale non empirical calculations, extending the prewar work of Hartree and Fock from many-electron atoms to many-electron molecules-and thus into "real chemistry."

"Linear-Scaling Techniques in Computational Chemistry and Physics" summarizes recent progresses in linear-scaling techniques and their applications in chemistry and physics. In order to meet the needs of a broad community of chemists and physicists, the book focuses on recent advances that extended the scope of possible exploitations of the theory.

The first chapter provides an overview of the present state of the linear-scaling methodologies and their applications, outlining hot topics in this field, and pointing to expected developments in the near future. This general introduction is then followed by several review chapters written by experts who substantially contributed to recent developments in this field.

The purpose of this book is to review, in a systematic manner, recent developments in linear-scaling methods and their applications in computational chemistry and physics. Great emphasis is put on the theoretical aspects of linear-scaling methods.

This book serves as a handbook for theoreticians, who are involved in the development of new efficient computational methods as well as for scientists, who are using the tools of computational chemistry and physics in their research.

The focus of this thesis is the computational modelling of transition metal bimetallic (nanoalloy) clusters. More specifically, the study of Pd-Pt, Ag-Pt, Au-Au and Pd-Au as a few tens of atoms in the gas phase. The author used a combination of global optimization techniques - coupled with a Gupta-type empirical many-body potential - and Density Functional Theory (DFT) calculations to study the structures, bonding and chemical ordering, as well as investigate the chemisorptions of hydrogen and carbon monoxide on bimetallic clusters. This research is highly relevant to experimental catalytic studies and has resulted in more than seven publications in international journals.

This monograph describes and discusses the properties of heterogeneous materials, including conductivity, elastic moduli, and dielectrical constant. The book outlines typical experimental methods, and compares the experimental data and the theoretical predictions. This multidisciplinary book will appeal to applied physicists, materials scientists, chemical and mechanical engineers, chemists, and applied mathematicians.