Ab Initio Calculations

Ab Initio Calculations PDF Author: Petr Carsky
Publisher: Springer Science & Business Media
ISBN: 3642931405
Category : Science
Languages : en
Pages : 256

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Book Description
Until recently quantum chemical ab initio calculations were re stricted to atoms and very small molecules. As late as in 1960 Allen l and Karo stated : "Almost all of our ab initio experience derives from diatomic LCAO calculations ••• N and we have found in the litera ture "approximately eighty calculations, three-fourths of which are for diatomic molecules ••• There are approximately twenty ab initio calculations for molecules with more than two atoms, but there is a decided dividing line between the existing diatomic and polyatomic wave functions. Confidence in the satisfactory evaluation of the many -center two-electron integrals is very much less than for the diatom ic case". Among the noted twenty calculations, SiH was the largest 4 molecule treated. In most cases a minimal basis set was used and the many-center two-electron integrals were calculated in an approximate way. Under these circumstances the ab initio calculations could hard ly provide useful chemical information. It is therefore no wonder that the dominating role in the field of chemical applications was played by semiempirical and empirical methods. The situation changed essentially in the next decade. The problem of many-center integrals was solved, efficient and sophisticated computer programs were devel oped, basis sets suitable for a given type of problem were suggested, and, meanwhile, a considerable amount of results has been accumulated which serve as a valuable comparative material. The progress was of course inseparable from the development and availability of computers.

Ab Initio Calculations

Ab Initio Calculations PDF Author: Petr Carsky
Publisher: Springer Science & Business Media
ISBN: 3642931405
Category : Science
Languages : en
Pages : 256

Get Book Here

Book Description
Until recently quantum chemical ab initio calculations were re stricted to atoms and very small molecules. As late as in 1960 Allen l and Karo stated : "Almost all of our ab initio experience derives from diatomic LCAO calculations ••• N and we have found in the litera ture "approximately eighty calculations, three-fourths of which are for diatomic molecules ••• There are approximately twenty ab initio calculations for molecules with more than two atoms, but there is a decided dividing line between the existing diatomic and polyatomic wave functions. Confidence in the satisfactory evaluation of the many -center two-electron integrals is very much less than for the diatom ic case". Among the noted twenty calculations, SiH was the largest 4 molecule treated. In most cases a minimal basis set was used and the many-center two-electron integrals were calculated in an approximate way. Under these circumstances the ab initio calculations could hard ly provide useful chemical information. It is therefore no wonder that the dominating role in the field of chemical applications was played by semiempirical and empirical methods. The situation changed essentially in the next decade. The problem of many-center integrals was solved, efficient and sophisticated computer programs were devel oped, basis sets suitable for a given type of problem were suggested, and, meanwhile, a considerable amount of results has been accumulated which serve as a valuable comparative material. The progress was of course inseparable from the development and availability of computers.

Quantum-Mechanical Ab-initio Calculation of the Properties of Crystalline Materials

Quantum-Mechanical Ab-initio Calculation of the Properties of Crystalline Materials PDF Author: Cesare Pisani
Publisher: Springer Science & Business Media
ISBN: 3642614787
Category : Science
Languages : en
Pages : 331

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Book Description
A number of general-purpose, reasonably accurate and well-tested ab-initio codes for crystals are discussed in this book. The aim is to expand competence of their application in material sciences and solid-state physics. The book addresses particularly readers with a general knowledge in quantum chemistry and intends to give a deeper insight into the special algorithms and computational techniques in ab-initio computer codes for crystals. Three different programs which are available to all interested potential users on request are presented.

Computational Chemistry

Computational Chemistry PDF Author: Errol G. Lewars
Publisher: Springer Science & Business Media
ISBN: 0306483912
Category : Science
Languages : en
Pages : 474

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Book Description
Computational chemistry has become extremely important in the last decade, being widely used in academic and industrial research. Yet there have been few books designed to teach the subject to nonspecialists. Computational Chemistry: Introduction to the Theory and Applications of Molecular and Quantum Mechanics is an invaluable tool for teaching and researchers alike. The book provides an overview of the field, explains the basic underlying theory at a meaningful level that is not beyond beginners, and it gives numerous comparisons of different methods with one another and with experiment. The following concepts are illustrated and their possibilities and limitations are given: - potential energy surfaces; - simple and extended Hückel methods; - ab initio, AM1 and related semiempirical methods; - density functional theory (DFT). Topics are placed in a historical context, adding interest to them and removing much of their apparently arbitrary aspect. The large number of references, to all significant topics mentioned, should make this book useful not only to undergraduates but also to graduate students and academic and industrial researchers.

Diatomic Molecules

Diatomic Molecules PDF Author: Robert Mulliken
Publisher: Academic Press
ISBN:
Category : Science
Languages : en
Pages : 232

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Book Description
Diatomic Molecules: Results of Ab Initio Calculations provides the results obtained from quantum-mechanical calculations on the electronic structure of diatomic molecules. This six-chapter text also discusses the related concepts of ab initio calculation methods. This book considers first the primary methods used in the computation of molecular wave functions and of related properties. This topic is followed by discussions on the linear combination of atomic orbital and linear combination of mixed atomic orbital approximations and basis sets; electronic population analysis; spectroscopic transition probabilities; and the nature of chemical bonding. The remaining chapters examine the features of various theories that become prominent when two or more electrons are present, or are important in hydrides or homopolar and heteropolar molecules. This text will be of great value to organic and inorganic chemists and physicists.

Molecular Magnetic Materials

Molecular Magnetic Materials PDF Author: Barbara Sieklucka
Publisher: John Wiley & Sons
ISBN: 3527339531
Category : Science
Languages : en
Pages : 508

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Book Description
A comprehensive overview of this rapidly expanding interdisciplinary field of research. After a short introduction to the basics of magnetism and molecular magnetism, the text goes on to cover specific properties of molecular magnetic materials as well as their current and future applications. Design strategies for acquiring molecular magnetic materials with desired physical properties are discussed, as are such multifunctional materials as high Tc magnets, chiral and luminescent magnets, magnetic sponges as well as photo- and piezo-switching magnets. The result is an excellent resource for materials scientists, chemists, physicists and crystal engineers either entering or already working in the field.

Ab initio Calculation Tutorial

Ab initio Calculation Tutorial PDF Author: Ryo Maezono
Publisher: Springer Nature
ISBN: 9819909198
Category : Science
Languages : en
Pages : 286

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Book Description
This textbook covers the framework of first-principles analysis applied to materials using density functional theory (DFT). It provides a set of hands-on tutorials using the Quantum ESPRESSO package, an open-source software for DFT. The tutorials are well chosen, designed for maximum effectiveness while requiring a minimum of the reader’s time, and the book describes how the essential components are combined to create the practical applications based on the idea of modeling practical problems of materials. The book carefully explains how to prepare the platform to run the tutorials assisted by free software. This textbook is useful for students in experimental laboratories, for industrial researchers, and for those not majoring in theoretical studies but learning individually.

Metal Nanoclusters in Catalysis and Materials Science: The Issue of Size Control

Metal Nanoclusters in Catalysis and Materials Science: The Issue of Size Control PDF Author: Benedetto Corain
Publisher: Elsevier
ISBN: 0080555004
Category : Technology & Engineering
Languages : en
Pages : 471

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Book Description
Metal Nanoclusters in Catalysis and Materials Science: The Issue of Size Control deals with the synthesis of metal nanoclusters along all known methodologies. Physical and chemical properties of metal nanoclusters relevant to their applications in chemical processing and materials science are covered thoroughly. Special attention is given to the role of metal nanoclusters size and shape in catalytic processes and catalytic applications relevant to industrial chemical processing.An excellent text for expanding the knowledge on the chemistry and physics of metal nanoclusters. Divided in two parts; Part I deals with general aspects of the matter and Part II has to be considered a useful handbook dealing with the production of metal nanoclusters, especially from their size-control point of view.* Divided into two parts for ease of reference: general and operational * Separation of synthetic aspects, physical properties and applications* Specific attention is given to the task of metal nanoclusters size-control

Ab Initio Molecular Dynamics

Ab Initio Molecular Dynamics PDF Author: Dominik Marx
Publisher: Cambridge University Press
ISBN: 1139477196
Category : Science
Languages : en
Pages : 503

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Book Description
Ab initio molecular dynamics revolutionized the field of realistic computer simulation of complex molecular systems and processes, including chemical reactions, by unifying molecular dynamics and electronic structure theory. This book provides the first coherent presentation of this rapidly growing field, covering a vast range of methods and their applications, from basic theory to advanced methods. This fascinating text for graduate students and researchers contains systematic derivations of various ab initio molecular dynamics techniques to enable readers to understand and assess the merits and drawbacks of commonly used methods. It also discusses the special features of the widely used Car–Parrinello approach, correcting various misconceptions currently found in research literature. The book contains pseudo-code and program layout for typical plane wave electronic structure codes, allowing newcomers to the field to understand commonly used program packages and enabling developers to improve and add new features in their code.

Molecular Structure and Statistical Thermodynamics

Molecular Structure and Statistical Thermodynamics PDF Author: Kenneth S. Pitzer
Publisher: World Scientific
ISBN: 9812795960
Category : Science
Languages : en
Pages : 537

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Book Description
This book considers molecular structural information, statistical methods and thermodynamic measurements, and the ways in which the relative role of each differs from another. By putting together selected papers in a single publication, the book highlights the cohesive aspects of certain advances through time and development, and can aid historical studies. Several papers from journals not widely circulated can also be found in this selection of papers.

Electrons, Atoms, and Molecules in Inorganic Chemistry

Electrons, Atoms, and Molecules in Inorganic Chemistry PDF Author: Joseph J. Stephanos
Publisher: Academic Press
ISBN: 012811049X
Category : Science
Languages : en
Pages : 764

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Book Description
Electrons, Atoms, and Molecules in Inorganic Chemistry: A Worked Examples Approach builds from fundamental units into molecules, to provide the reader with a full understanding of inorganic chemistry concepts through worked examples and full color illustrations. The book uniquely discusses failures as well as research success stories. Worked problems include a variety of types of chemical and physical data, illustrating the interdependence of issues. This text contains a bibliography providing access to important review articles and papers of relevance, as well as summaries of leading articles and reviews at the end of each chapter so interested readers can readily consult the original literature. Suitable as a professional reference for researchers in a variety of fields, as well as course use and self-study. The book offers valuable information to fill an important gap in the field. - Incorporates questions and answers to assist readers in understanding a variety of problem types - Includes detailed explanations and developed practical approaches for solving real chemical problems - Includes a range of example levels, from classic and simple for basic concepts to complex questions for more sophisticated topics - Covers the full range of topics in inorganic chemistry: electrons and wave-particle duality, electrons in atoms, chemical binding, molecular symmetry, theories of bonding, valence bond theory, VSEPR theory, orbital hybridization, molecular orbital theory, crystal field theory, ligand field theory, electronic spectroscopy, vibrational and rotational spectroscopy