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.

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.

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

Get Book Here

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.

AB Initio Calculation of the Structures and Properties of Molecules

AB Initio Calculation of the Structures and Properties of Molecules PDF Author: Clifford E. Dykstra
Publisher: Elsevier Publishing Company
ISBN:
Category : Science
Languages : en
Pages : 296

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Book Description
This book is intended as a guide to the ab initio calculation of molecular structure and properties. It provides the necessary working information to enable the non-specialist to use and understand electronic structure methods and related computing technology, despite the high level of sophistication of quantum chemical methods. The initial chapters define and outline theoretical concepts, methods and computational approaches. Descriptive information and definitions of the terminology are given first; more detailed and mathematical explanations follow. These first chapters thus provide the background information needed to use the extensive literature of ab initio electronic structure theory. The next chapter first provides an overview of the technical issues relating to molecular properties, and then gives a rather detailed but general development. The latter part of this chapter is mainly intended for those first encountering the methodologies of properties determination and intending to pursue further developments. The other chapters provide reviews of calculations in the literature and assessments of factors influencing accuracy. The book is particularly useful to those who need a working understanding of ab initio calculations and well-suited to graduate students and researchers in computational and theoretical chemistry, researchers in electronic structure, spectroscopists and organic chemists.

Diatomic Molecules

Diatomic Molecules PDF Author: Robert Mulliken
Publisher: Elsevier
ISBN: 0323160077
Category : Science
Languages : en
Pages : 214

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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.

Ab Initio Molecular Orbital Calculations for Chemists

Ab Initio Molecular Orbital Calculations for Chemists PDF Author: William Graham Richards
Publisher: Oxford University Press, USA
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 134

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Book Description


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.

Ab Initio Valence Calculations in Chemistry

Ab Initio Valence Calculations in Chemistry PDF Author: D. B. Cook
Publisher: Butterworth-Heinemann
ISBN: 1483161218
Category : Science
Languages : en
Pages : 282

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Book Description
Ab Initio Valence Calculations in Chemistry describes the theory and practice of ab initio valence calculations in chemistry and applies the ideas to a specific example, linear BeH2. Topics covered include the Schrödinger equation and the orbital approximation to atomic orbitals; molecular orbital and valence bond methods; practical molecular wave functions; and molecular integrals. Open shell systems, molecular symmetry, and localized descriptions of electronic structure are also discussed. This book is comprised of 13 chapters and begins by introducing the reader to the use of the Schrödinger equation to solve the electronic structure of molecular systems. This discussion is followed by two chapters that describe the chemical and mathematical nature of orbital theories in quantum chemistry. Two general ways of using chemical and physical information in looking for approximate solutions of the Schrödinger equation are highlighted: model approximations and numerical approximations. Attention then turns to atomic orbitals as the basis of a description of molecular electronic structure; practical molecular wave functions; and a general strategy for performing molecular valence calculations. The final chapter examines the nature of the valence electronic structure by using invariance with respect to transformations among the occupied molecular orbitals and among the atomic orbitals. This text will be of interest to students and practitioners of chemistry, biochemistry, and quantum mechanics.

Ab initio calculations

Ab initio calculations PDF Author:
Publisher:
ISBN: 9781773618838
Category :
Languages : en
Pages : 0

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Book Description


Ab Initio Variational Calculations of Molecular Vibrational-Rotational Spectra

Ab Initio Variational Calculations of Molecular Vibrational-Rotational Spectra PDF Author: Debra J. Searles
Publisher: Springer Science & Business Media
ISBN: 3662055619
Category : Science
Languages : en
Pages : 245

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Book Description
This work had its beginnings in the early 1980s at the University ofWollongong, with significant contributions from Dr. Margret Hamilton, Professors Peter G. Burton and Greg Doherty. The emphasis was to develop computer code to solve the nuclear Schrodinger problem. For bent triatomic molecules the project was fmally realized at the University of Newcastle a decade or so later, with the contribution from Ms. Feng Wan g. Aspects of this work are now taught in the quantum mechanics and electron spectroscopy courses at The University of Newcastle. Even now "complete" ab initio solutions of the time-independent SchrOdinger equation is not commonplace for molecules containing four atoms or more. In fact, when using the Eckart-Watson nuclear Hamiltonian a further restriction needs to be imposed; that is, the molecule is restricted to undergoing small amplitudes of vibration. This Hamiltonian is useful for molecules containing massive nuclei and moreover, has been extremely useful in interpreting the rovibrational spectra of small molecules. Nevertheless, a number of nuclear Hamiltonians that do not embed an equilibrium geometry have become well established and are extremely successful in interpreting rovibrational spectra of floppy molecules. Furthermore, solution algorithms vary greatly from research group to research group and it is still unclear which aspects will survive the next decade. For example, even for a triatomic molecule a general form of a potential function has not yet been uncovered that will generally interpolate with accuracy and precision ab initio discrete surfaces.

Polyatomic Molecules

Polyatomic Molecules PDF Author: Robert S. Mulliken
Publisher: Elsevier
ISBN: 0323149944
Category : Science
Languages : en
Pages : 448

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Book Description
Polyatomic Molecules: Results of Ab Initio Calculations describes the symmetry of polyatomic molecules in ground states. This book contains 12 chapters that also cover the excited and ionized states of these molecules. The opening chapter describes the nature of the various ab initio computational methods. The subsequent four chapters deal with the three-atom systems, differing with respect to the number of hydrogen atoms in the molecules. These chapters also discuss the reaction surfaces of these systems. These topics are followed by discussions on the molecules whose ground states belong to relatively high, little or no symmetry groups. The concluding chapters explore the inorganic and relatively large organic molecules. These chapters also examine the ab initio calculations of molecular compounds and complexes, as well as hydrogen bonding and ion hydration. This text will be of great value to organic and inorganic chemists and physicists.