Download or read book Selected Topics of the Theory of Chemical Elementary Processes written by E.E. Nikitin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction 1 1. 2. Basic Concepts and Phenomenological Description 6 2.1. Separation of the Center-of-Mass Motion 8 2.2. Separation of Electronic and Nuclear Motions. Interaction Potentials (Potential-Energy Surfaces) 11 2.2.1. Heuristic Considerations 11 2.2.2. Born-Oppenheimer Separation. Adiabatic Approximation, 16 Present State of Potential-Energy-Burface 2.2.3. Calculations 23 2.3. Scattering Channels ~6 2.4. Classification of Elementary Processes. Microscopic Mechanism 27 D.ynamics of Atomic and Molecular Collisions: 3. Electronically Adiabatic Processes 32 Classical Approach 3.1. 33 Some Arguments for the Reliability of the Classical Approach 33 Atom-Atom Collisions. Elastic Scattering 34 Quasiclassical Treatment of Elementary Processes in Triatomic Systems: Inelastic and Reactive Scattering 44 IV Examples of Results of Trajectory Calculations 59 3.1.4. 64 Elements of Quantum-Mechanical Methods 3.2. Correspondence of Classical and Quantum 3.2.1. 64 Mechanical Theories Time-Dependent Scattering Theory 71 3.2.2. Stationary Scattering Theory 77 3.2.3. One-Dimensional Scattering 78 3.2.3.1 • Three-Dimensional Elastic Scattering 83 3.2.3.2. Rearrangement Scattering (Reactions) 85 3.2.3.3. Examples of Quantum-Mechanical Calculations 3.2.4.

Download or read book Theory of Chemical Reaction Dynamics written by Antonio Laganà and published by Springer Science & Business Media. This book was released on 2006-03-28 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Research Workshop, held in Balatonföldvár, Hungary, 8-12 June 2003

Download or read book Radiation Chemical Processes in Solid Phase written by Evginiy I. Grigoriev and published by CRC Press. This book was released on 1996-11-14 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unlike many other references, Radiation-Chemical Processes in Solid Phase analyzes experimental data on radiolysis in terms of solid-state physics. It traces the effect exerted by media from primary processes of radiation-substance interaction to final products. The authors consider the main chemically active elementary excitations arising under irradiation of solids and discuss the mechanisms of chemical reactions induced by them. They present the general principles of solid-state and molecular physics, and cover numerous radiation-chemical processes.

Download or read book Many Body Methods in Quantum Chemistry written by Uzi Kaldor and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume contains the text of the invited lectures presented at the Symposium on Many Body Methods in Quantum Chemistry, held on the campus of Tel Aviv University in August 1988. The Symposium was a satellite meeting of the Sixth International Congress on Quantum Chemistry held in Jerusalem. The development and application of many-body methods in Quantum chemistry have been on the rise for a number of years. This is therefore a good time for an interim report on the state of the field. It is hoped that such a report is hereby provided, though it may not be complete. The Symposium was held under the auspices of Tel Aviv University, Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry. Other sponsors were the Israeli Academy of Sciences and Humanities, and the Israeli Ministry of Science and Development. Many thanks go to all of them. Finally, I would like to thank all the speakers and participants for making the meeting the enjoyable and (I hope) profitable experience it was. Tel Aviv, Israel Uzi Kaldor TESTS AND APPLICATIONS OF COMPLETE MODEL SPACE QUASIDEGENERATE MANY-BODY PERTURBATION THEORY FOR MOLECULES Karl F. Freed The James Franck Institute and Department of Chemistry The University of Chicago, Chicago, DUnois 60637 U.S.A.

Download or read book Collision Theory and Statistical Theory of Chemical Reactions written by S. G. Christov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of quantum mechanics,more than fifty years ago,the theory of chemical reactivity has taken the first steps of its development. The knowledge of the electronic structure and the properties of atoms and molecules is the basis for an un derstanding of their interactions in the elementary act of any chemical process. The increasing information in this field during the last decades has stimulated the elaboration of the methods for evaluating the potential energy of the reacting systems as well as the creation of new methods for calculation of reaction probabili ties (or cross sections) and rate constants. An exact solution to these fundamental problems of theoretical chemistry based on quan tum mechanics and statistical physics, however, is still impossible even for the simplest chemical reactions. Therefore,different ap proximations have to be used in order to simplify one or the other side of the problem. At present, the basic approach in the theory of chemical reactivity consists in separating the motions of electrons and nu clei by making use of the Born-Oppenheimer adiabatic approximation to obtain electronic energy as an effective potential for nuclear motion. If the potential energy surface is known, one can calculate, in principle, the reaction probability for any given initial state of the system. The reaction rate is then obtained as an average of the reaction probabilities over all possible initial states of the reacting ~artic1es. In the different stages of this calculational scheme additional approximations are usually introduced.

Download or read book Angular Momentum Theory Applied to Interactions in Solids written by Clyde A. Morrison and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: From December 1985 through March 1986 the text of this book formed the basis of an in-hours course taught by the author at Harry Diamond Laborato ries. Considerable assistance in revising and organizing the first draft was given by John Bruno. The original draft of these notes was based on a collection of lectures delivered at the Universidade Federal de Pernambuco, Recife, Brazil, between 2 November 1981 and 2 December 1981. The visit to Recife was a response to an invi tation of Professor Gilberto F. de Sa of the Physics Department. In the preparation of these notes I made many requests of my coworkers for earlier resul ts and recollections of our early work. Among those consul ted were Donald Wortman, Nick Karayianis, and Richard Leavitt. Further, a number of .suggestions from my Brazilian colleagues helped make the lectures more clear. Particular among these were Professor Oscar Malta and Professor Alfredo A. da Gama both of whom I wish to thank for their help. Encouragement and assistance with funding for much of this work came from Leon Esterowitz of the Naval Research Laboratory and Rudolph Buser and Albert Pinto of the center for Night Vision and Electro-Optics.

Download or read book The Positive Muon as a Probe in Free Radical Chemistry written by Emil Roduner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented here is a result of an extended collaboration with a number of coworkers and guests. Particularly, I would like to thank Dr. P. Burkhard and Dr. W. Strub for their careful work performed for their Ph. D. thesis and Dr. M. Heming for his brilliant ideas and his dedication. Very fruitful and stimulating were collaborations with our guests, i. e. with G. A. Brinkman and P. W. F. Louwrier from NIKHEF-K in Amsterdam, B. C. Webster, M. J. Ramos and D. McKenna from the University of Glasgow, M. C. R. Symons, D. Geeson and C. J. Rhodes from the University of Leicester, S. F. J. Cox and C. A. Scott from the Rutherford Appleton Laboratory in Chilton, and R. De Renzi and M. Ricco from the University of Parma. Many invaluable discussions with friends and competitors in the field helped to address new viewpoints and to define new goals. I shall not forget my teacher and director of the radical chemistry group, Prof. H. Fischer, whom I wish to thank for his interest and active support and for the great liberty he allowed me for the planning and organization of the project. Last but not least, I thank my dear wife Hanny and our children Christian, Martin and Andrea who suffered, without complaint, daddy's absence for so many hours.

Download or read book Synthon Model of Organic Chemistry and Synthesis Design written by Jaroslav Koca and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most interesting fields of mathematically oriented chemical research is the so-called computer-assisted organic synthesis design. These lecture notes elaborate the mathematical model of organic chemistry, which offers formal concepts for unambiguous description of computer algorithms for organic synthesis design including retrosynthesis and reaction mechanisms. All definitions and theorems are supplemented by many illustrative examples. The model is closely related to the course of thinking of organic chemists. These notes will be useful for all theoretically oriented organic chemists who are interested in mathematical modelling of organic chemistry and computer-assisted organic synthesis design.

Download or read book Unified Valence Bond Theory of Electronic Structure written by N. D. Epiotis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bond diagrammatic representation of molecules is the foundation of MOVB theory. To a certain extent, this kind of representation is analogous to the one on which "resonance theory" is based and this fact can be projected by a comparison of the various ways in which MOVB theory depicts a species made up of three core and two ligand MO's which define two subsystems containing a total of six electrons and the ways in which "resonance theory" (i. e. , qualitative VB theory) depicts a six-electron-six-AO species such as the pi system of CH =CH-CH=CH-CH=O. The 2 different pictorial representations are shown in Scheme 1 so that the analogies are made evident. First of all, the total MOVB diagrammatic representation of the 6/5 species is obtained by a linear combination of three complete bond diagrams, as in Al, which describe the optimal linear combination of!l! MOVB Configuration Wavefunctions (CW's). By the same token, a total VB diagrammatic representation of the 6/6 species can be obtained by writing a "dot structure", as in Bl, and taking this to mean the optimal linear combination of all VB CW's. Next, we can approxi mate the MOVB wavefunction of the 6/5 species by one complete (or detailed) bond dia gram" (A2). No simple VB representation analogy can be given in this case. Alterna tively, we can approximate the MOVB wavefunction by a linear combination of compact bond diagrams, as in A3, in the way described before.

Download or read book Pattern Recognition in Chemistry written by Kurt Varmuza and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical chemistry of the recent years is strongly influenced by automation. Data acquisition from analytica~ instruments - and some times also controlling of instruments - by a computer are principally solved since many years. Availability of microcomputers made these tasks also feasible from the economic point of view. Besides these basic applications of computers in chemical measurements scientists developed computer programs for solving more sophisticated problems for which some kind of "intelligence" is usually supposed to be necessary. Harm less numerical experiments on this topic led to passionate discussions about the theme "which jobs cannot be done by a computer but only by human brain ?~. If this question is useful at all it should not be ans wered a priori. Application of computers in chemistry is a matter of utility, sometimes it is a social problem, but it is never a question of piety for the human brain. Automated instruments and the necessity to work on complex pro blems enhanced the development of automatic methods for the reduction and interpretation of large data sets. Numerous methods from mathematics, statistics, information theory, and computer science have been exten sively investigated for the elucidation of chemical information; a new discipline "chemometrics" has been established. Three different approaches have been used for computer-assisted interpretations of chemical data. 1. Heuristic methods try to formu late computer programs working in a similar way as a chemist would solve the problem. 2.

Download or read book Hypervirial Theorems written by Francisco M. Fernandez and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Time Dependent Reactivity of Species in Condensed Media written by Andrzej Plonka and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: These notes on the use of one particular form of the time-dependent rate constant to describe the reaction patterns in condensed media have been put together primarily to encourage chemists to try and accept this new way of experimental data treatment. A number of applications is shown and interpretative aspects are discussed. Emphasized are the problems that need to be currently solved. Some of them are also of current interest in condensed phase physics from which the chemical kinetics benefits a great deal. It was inevitable that the choice of subject matter from both rapidly expanding fields and its form of pre sentation reflect to some extent the author's own interests and some important topics are treated briefly or even omitted. Fully recognizing this, I would like to acknowledge with gratitude the contributions to the subject of all my coworkers in the Laboratories of Lodz, Detroit Mi, MUlheim/Ruhr, and Houston Tx, and of those who helped me in preparing this text. Dr. Wlodzi~ierz Lefik and my son WojciecQ recalculated most of the experimental results, Mrs. Aleksandra Karczewska redrew all the figures. Special thanks go to my wife Ewa for her invaluable assistance in all works and for the final form of the text. AP Lodz, February 1986 CONTENTS 1. Introduction 1 2. Reaction kinetics of species trapped in glassy matrices 6 Excess electrons (6): Post-irradiated decay (6). Spectral relaxation (11). Photostimulated decay (15). Photostimu lated conversion into trapped hydrogen atoms (17). Radio luminescence kinetics (21).

Download or read book Electrochemistry on Liquid Liquid Interfaces written by Petr Vanysek and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: A charge transfer across the interface between two immiscible liquid media has an important role both in nature and in man-designed applications. Ion transfer across the biological membranes, behavior of ion-selective electrodes with liquid membranes and similar sensors, extraction processes, phase transfer catalysis and applications in electroanalytical chemistry can serve as examples. Present interest in the interface between two immiscible electrolytes (liquid liquid or L/L interface) was originated by Koryta's idea (Koryta, Vanysek and Brezina 1976) that the interface between immiscible liquids could serve as a simple model for one half of a biological membrane in the contact with the surrounding electrolyte. It was also Koryta who started using the acronym ITIES (Interface between Two Immiscible Electrolyte Solutions) which generally encompasses all the phenomena discussed in this book. Physiological and electrochemical investigations have certainly well established tradition. In his classic experiments with frog thighs Luigi Galvani discovered in 1791 relationship between electricity and nerves and muscles. As outlined by Koryta and Stullk (1983) in the introduction to their book, the study of electrophysiological phenomena did not progress much for several decades and only a few experiments were performed. For instance M. Faraday (Williams, 1965) studied the electricity produced by an electric fish and Du Bois-Reymond (1848) suggested that the surface of biological formations have properties similar to the electrode of a galvanic cell. However, the properties of biological membrane could not be explained before the first concept of electrochemistry was postulated.

Download or read book Perspectives in Theoretical Stereochemistry written by I. Ugi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stereochemistry is the part of chemistry that relates observable prop erties of chemical compounds to the structure of their molecules, i. e. the relative spatial arrangement of their constituent atoms. In classical stereochemistry, the spatial arrangements relevant for interpreting and predicting a given chemical property are customarily described by geometric features/ symmetries in some suitably chosen rigid model of the molecule The solution of stereochemical problems involving single molecular species is the danain of the geometry based approaches, such as the methods of classical stereochemistry, molecular mechanics and quantum chemistry. The molecules of a pure chemical compound form generally an ensemble of molecular individuals that differ in geometry and energy. Thus it is generally impossible to represent a chemical compund adequately by the geo metry of a rigid molecular model. In modern stereochemistry it is often necessary to analyze molecular relation within ensembles and families of stereoisomers and permutation isomers, including molecules whose geometric features are changing with time. Accordingly, there is definitely a need for new types of ideas, concepts, theories and techniques that are usable beyond the scope of customary methodology. This is why the present text was written.

Download or read book Potential Energy Functions in Conformational Analysis written by Kjeld Rasmussen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: I get by with a little help from my friends The Beatles: Sgt. Pepper This book should have been in Danish. Any decent person must be able to express himself in his mother's tongue, also when expounding scientific ideas and results. Had I stuck to this ideal, the book would have been read by very few people, and, indeed, appreciated by even fewer. Having it publ ished in English gives me a chance to fulfill one ambition: to be read and judged by the international scientific community. Another reason is that the majority of my professional friends are regrettably unread in Danish, just as I am in Hebrew, Finnish and even Italian. I want to deprive them of the most obvious excuse for not reading my opus. Like a man I admired, I will first of all thank my wife. In his autobiography, Meir Weisgal, then President of the Weizmann Insti tute of SCience, wrote about his wife: "In addition to her natural endowments - which are considerable - she was a more than competent part-tim~ secretary." He wrote on, and so shall I. The book has been edited by my wife. So if the reader finds the layout pleasant as, in actual fact, I myself do, Birgit is to be praised. If there are blemishes, I am to be blamed for not having caught them.

Download or read book GRMS or Graphical Representation of Model Spaces written by Wlodzislaw Duch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of these notes is to give some simple tools and pictures to physicists and ' chemists working on the many-body problem. Abstract thinking and seeing have much in common - we say "I see" meaning "I understand" , for example. Most of us prefer to have a picture of an abstract object. The remarkable popularity of the Feynman diagrams, and other diagrammatic approaches to many-body problem derived thereof, may be partially due to this preference. Yet, paradoxically, the concept of a linear space, as fundamental to quantum physics as it is, has never been cast in a graphical form. We know that is a high-order contribution to a two-particle scattering process (this one invented by Cvitanovic(1984)) corresponding to a complicated matrix element. The lines in such diagrams are labeled by indices of single-particle states. When things get complicated at this level it should be good to take a global view from the perspective of the whole many-particle space. But how to visualize the space of all many-particle states ? Methods of such visualization or graphical representation of the ,spaces of interest to physicists and chemists are the main topic of this work.

Download or read book Hartree Fock Ab Initio Treatment of Crystalline Systems written by Cesare Pisani and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a computational scheme for calculating the electronic properties of crystalline systems at an ab-ini tio Hartree-Fock level of approximation. The first chapter is devoted to discussing in general terms the limits and capabilities of this approximation in solid state studies, and to examining the various options that are open for its implementation. The second chapter illustrates in detail the algorithms adopted in one specific computer program, CRYSTAL, to be submitted to QCPE. Special care is given to illustrating the role and in:fluence of computational parameters, because a delicate compromise must always be reached between accuracy and costs. The third chapter describes a number of applications, in order to clarify the possible use of this kind of programs in solid state physics and chemistry. Appendices A, B, and C contain various standard expressions, formulae, and definitions that may be useful for reference purposes; appendix D is intended to facilitate the interpretations of symbols, conventions, and acronyms that occur in the book. Thanks are due to all those who have contributed to the implementation and test of the CRYSTAL program, especially to V.R. Saunders and M. Causal, and to F. Ricca, E. Ferrero, R. Or lando, E. Ermondi, G. Angonoa, P. Dellarole, G. Baracco.