Download or read book Ab initio calculation of the structures and properties of molecules written by Clifford E. Dykstra and published by . This book was released on 1988 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compendium of Ab Initio Calculations of Molecular Energies and Properties written by Morris Krauss and published by . This book was released on 1967 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diatomic Molecules written by Robert Mulliken and published by Elsevier. This book was released on 2012-12-02 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ab Initio Calculation of Molecular Properties written by K. Somasundram and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Mechanical Ab initio Calculation of the Properties of Crystalline Materials written by Cesare Pisani and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ab Initio Calculations of Molecular Structure and Properties Using the Spin coupled Wavefunction written by Peter Alan Hyams and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ab Initio Calculations of Molecular Structure and Properties written by and published by . This book was released on 2007 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ab Initio Determination of Molecular Properties written by Alan Hinchliffe and published by CRC Press. This book was released on 1987 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational quantum chemistry was born in the mid 1960s, and had by the early 1980s achieved considerable status as a structural tool within chemistry. The field has now developed to the point where it has its own journals. However, a major change is taking place in that most consumers of computational quantum chemistry are now experimentalists, who want answers to questions of the type "What if.....?" This change has come about because of the dramatic fall in computer hardware costs, the ready availability of large molecular structure packages and the international collaboration between quantum chemists on a scale rarely witnessed in science. This book aims to show what can be done by computational chemistry, and what kind of reliance might be placed on the predictions. The vast majority of investigations are made at the 'ab initio self consistent field' level, and the results of such calculations occupy a prominent role in this book. However, the user has to be aware of the limitations of this model, and the effects upon electron correlation, etc are discussed. Anyone who is contemplating making use of the techniques of computational quantum chemistry to rationalise or predict chemical behaviour will find this unique book of tremendous use.
Download or read book Ab Initio Calculations written by Petr Carsky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ab Initio Electronic Structure Calculations of the Chemisorption Properties of H20 Molecules on the Ni3Al 001 Surface written by Mayra Tovar and published by . This book was released on 2003 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structures and Conformations of Non Rigid Molecules written by J. Laane and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the beginnings of modern chemistry, molecular structure has been a lively area of research and speculation. For more than half a century spectroscopy and other methods have been available to characterize the structures and shapes of molecules, particularly those that are rigid. However, most molecules are at least to some degree non-rigid and this non-rigidity plays an important role in such diverse areas as biological activity, energy transfer, and chemical reactivity. In addition, the large-amplitude vibrations present in non-rigid molecules give rise to unusual low-energy vibrational level patterns which have a dramatic effect on the thermodynamic properties of these systems. Only in recent years has a coherent picture of the energetics and dynamics of the conformational changes inherent in non-rigid (and semi-rigid) molecules begun to emerge. Advances have been made in a number of different experimental areas: vibrational (infrared and Raman) spectroscopy, rotational (microwave) spectroscopy, electron diffraction, and, most recently, laser techniques probing both the ground and excited electronic states. Theoretically, the proliferation of powerful computers coupled with scientific insight has allowed both empirical and ab initio methods to increase our understanding of the forces responsible for the structures and energies of non-rigid systems. The development of theory (group theoretical methods and potential energy surfaces) to understand the unique characteristics of the spectra of these floppy molecules has also been necessary to reach our present level of understanding. The thirty chapters in this volume contributed by the key speakers at the Workshop are divided over the various areas. Both vibrational and rotational spectroscopy have been effective at determining the potential energy surfaces for non-rigid molecules, often in a complementary manner. Recent laser fluorescence work has extended these types of studies to electronic excited states. Electronic diffraction methods provide radial distribution functions from which both molecular structures and compositions of conformational mixtures can be found. Ab initio calculations have progressed substantially over the past few years, and, when carried out at a sufficiently high level, can accurately reproduce (or predict ahead of time) experimental findings. Much of the controversy of the ARW related to the question of when an ab initio is reliable. Since the computer programs are readily available, many poor calculations have been carried out. However, excellent results can be obtained from computations when properly done. A similar situation exists for experimental analyses. The complexities of non-rigid molecules are many, but major strides have been taken to understand their structures and conformational processes.
Download or read book Polyatomic Molecules written by Robert S. Mulliken and published by Elsevier. This book was released on 2012-12-02 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ab Initio Valence Calculations in Chemistry written by D. B. Cook and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Molecular Electronic Structure Theory written by Trygve Helgaker and published by John Wiley & Sons. This book was released on 2014-08-11 with total page 949 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ab initio quantum chemistry has emerged as an important tool in chemical research and is appliced to a wide variety of problems in chemistry and molecular physics. Recent developments of computational methods have enabled previously intractable chemical problems to be solved using rigorous quantum-mechanical methods. This is the first comprehensive, up-to-date and technical work to cover all the important aspects of modern molecular electronic-structure theory. Topics covered in the book include: * Second quantization with spin adaptation * Gaussian basis sets and molecular-integral evaluation * Hartree-Fock theory * Configuration-interaction and multi-configurational self-consistent theory * Coupled-cluster theory for ground and excited states * Perturbation theory for single- and multi-configurational states * Linear-scaling techniques and the fast multipole method * Explicity correlated wave functions * Basis-set convergence and extrapolation * Calibration and benchmarking of computational methods, with applications to moelcular equilibrium structure, atomization energies and reaction enthalpies. Molecular Electronic-Structure Theory makes extensive use of numerical examples, designed to illustrate the strengths and weaknesses of each method treated. In addition, statements about the usefulness and deficiencies of the various methods are supported by actual examples, not just model calculations. Problems and exercises are provided at the end of each chapter, complete with hints and solutions. This book is a must for researchers in the field of quantum chemistry as well as for nonspecialists who wish to acquire a thorough understanding of ab initio molecular electronic-structure theory and its applications to problems in chemistry and physics. It is also highly recommended for the teaching of graduates and advanced undergraduates.
Download or read book Ab Initio Molecular Dynamics written by Dominik Marx and published by Cambridge University Press. This book was released on 2009-04-30 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Atomic Hypothesis and the Concept of Molecular Structure written by Zvonimir B. Maksic and published by Springer. This book was released on 1990-06-13 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Imagination and shrewd guesswork are powerful instruments for acquiring scientific knowledge . . . " 1. H. van't Hoff The last decades have witnessed a rapid growth of quantum chemistry and a tremendous increase in the number of very accurate ab initio calculations of the electronic structure of molecules yielding results of admirable accuracy. This dramatic progress has opened a new stage in the quantum mechanical description of matter at the molecular level. In the first place, highly accurate results provide severe tests of the quantum mecha nics. Secondly, modern quantitative computational ab initio methods can be synergetically combined with various experimen tal techniques thus enabling precise numerical characterization of molecular properties better than ever anticipated earlier. However, the role of theory is not exhausted in disclosing the fundamental laws of Nature and production of ever increasing sets of data of high accuracy. It has to provide additionally a means of systematization, recognition of regularities, and ratio nalization of the myriads of established facts avoiding in this way complete chaos. Additional problems are represented by molecular wavefunctions provided by the modern high-level computational quantum chemistry methods. They involve, in principle, all the information on molecular system, but they are so immensely complex that can not be immediately understood in simple and physically meaningful terms. Both of these aspects, categorization and interpretation, call for conceptual models which should be preferably pictorial, transparent, intuitively appealing and well-founded, being sometimes useful for semi quantitative purposes.
Download or read book Computational Chemistry written by Jerzy Leszczynski and published by World Scientific. This book was released on 1996 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of recent progress in computational techniques as well as examples of the application of existing computational methods in different areas of chemistry, physics, and biochemistry. Introductory chapters cover a broad range of fundamental topics, including: state-of-the-art basis set expansion methods for computing atomic and molecular electronic structures based on the use of relativistic quantum mechanics; the most recent developments in Hartree-Fock methods, particularly in techniques suited for very large systems; the current analysis of the solute-solvent free energy of interaction and the physical bases used to evaluate the electrostatic, cavitation, and dispersion terms; an introduction to the additive fuzzy electron density fragmentation scheme within various ab initio Hartree-Fock quantum-chemical computational schemes, which has provided the means for generating representative molecular fragment densities characteristic to their local environment within a molecule. This book also features a review of recent ab initio calculations on the structure and interactions of DNA bases, a chapter on computational approaches to the design of safer drugs and their molecular properties, and a systematic conceptual study on a route which allows one to stuff fullerenes.
