Download or read book Symmetry Adapted Basis Sets written by John Avery and published by World Scientific. This book was released on 2012 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: In theoretical physics, theoretical chemistry and engineering, one often wishes to solve partial differential equations subject to a set of boundary conditions. This gives rise to eigenvalue problems of which some solutions may be very difficult to find. For example, the problem of finding eigenfunctions and eigenvalues for the Hamiltonian of a many-particle system is usually so difficult that it requires approximate methods, the most common of which is expansion of the eigenfunctions in terms of basis functions that obey the boundary conditions of the problem. The computational effort needed in such problems can be much reduced by making use of symmetry-adapted basis functions. The conventional method for generating symmetry-adapted basis sets is through the application of group theory, but this can be difficult. This book describes an easier method for generating symmetry-adapted basis sets automatically with computer techniques. The method has a wide range of applicability, and can be used to solve difficult eigenvalue problems in a number of fields. The book is of special interest to quantum theorists, computer scientists, computational chemists and applied mathematicians.
Download or read book Generalized Sturmians And Atomic Spectra written by John Scales Avery and published by World Scientific. This book was released on 2006-11-14 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the generalized Sturmian method, which offers a fresh approach to the calculation of atomic spectra. Generalized Sturmians are isoenergetic solutions to an approximate many-electron Schrödinger equation with a weighted potential. The weighting factors are chosen in such a way as to make all of the solutions correspond to a given energy. The advantage of such an isoenergetic basis set is that every basis function has the correct turning point behavior needed for efficient synthesis of the wave function.The book also discusses methods for automatic generation of symmetry-adapted basis sets. Calculations using the generalized Sturmian method are presented and compared with experimental results from the NIST database. The relationship of Sturmians to harmonic polynomials and hyperspherical harmonics is also described. Methods for treating angular functions and angular integrals by means of harmonic projection are discussed, and these methods are shown to be especially useful for relativistic calculations. A final chapter discusses application of the generalized Sturmian method to the calculation of molecular spectra.
Download or read book Computational Spectroscopy of Polyatomic Molecules written by Sergey Yurchenko and published by CRC Press. This book was released on 2023-02-18 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a detailed description of the modern variational methods available for solving the nuclear motion Schrödinger equation to enable accurate theoretical spectroscopy of polyatomic molecules. These methods are currently used to provide important molecular data for spectroscopic studies of atmospheres of astronomical objects including solar and extrasolar planets as well as cool stars. This book has collected descriptions of quantum mechanical methods into one cohesive text, making the information more accessible to the scientific community, especially for young researchers, who would like to devote their scientific career to the field of computational molecular physics. The book addresses key aspects of the high-accuracy computational spectroscopy of the medium size polyatomic molecules. It aims to describe numerical algorithms for the construction and solution of the nuclear motion Schrödinger equations with the central idea of the modern computational spectroscopy of polyatomic molecules to include the construction of the complex kinetic energy operators (KEO) into the computation process of the numerical pipeline by evaluating the corresponding coefficients of KEO derivatives on-the-fly. The book details key aspects of variational solutions of the nuclear motion Schrödinger equations targeting high accuracy, including construction of rotational and vibrational basis functions, coordinate choice, molecular symmetry as well as of intensity calculations and refinement of potential energy functions. The goal of this book is to show how to build an accurate spectroscopic computational protocol in a pure numerical manner of a general black-box type algorithm. This book will be a valuable resource for researchers, both experts and not experts, working in the area of the computational and experimental spectroscopy; PhD students and early-career spectroscopists who would like to learn basics of the modern variational methods in the field of computational spectroscopy. It will also appeal to astrophysicists and atmospheric physicists who would like to assess data and perform calculations themselves. Key features: Supported by the latest research and based on the state-of-the-art computational methods in high-accuracy computational spectroscopy of molecules. Authored by an authority in the field. Accessible to both experts and non-experts working in the area of computational and experimental spectroscopy, in addition to graduate students.
Download or read book Quantum Theory for Chemical Applications written by Jochen Autschbach and published by Oxford University Press, USA. This book was released on 2020-09-17 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Quantum Theory for Chemical Applications (QTCA) Quantum theory, or more specifically, quantum mechanics is endlessly fascinating, curious & strange, and often considered to be difficult to learn. It is true that quantum mechanics is a mathematical theory. Its scope, its predictions, the wisdom we gain from its results, all these become fully clear only in the context of the relevant equations and calculations. But the study of quantum mechanics is definitely worth the effort, and - as I like to tell my students- it is not rocket science"--
Download or read book Molecular Quantum Mechanics written by Peter W. Atkins and published by Oxford University Press. This book was released on 2011 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text unravels those fundamental physical principles which explain how all matter behaves. It takes us from the foundations of quantum mechanics, through quantum models of atomic, molecular, and electronic structure, and on to discussions of spectroscopy, and the electronic and magnetic properties of molecules.
Download or read book Basis Sets in Computational Chemistry written by Eva Perlt and published by Springer Nature. This book was released on 2021-05-06 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the construction and application of the major types of basis sets for computational chemistry calculations. In addition to a general introduction, it includes mathematical basics and a discussion of errors arising from incomplete or inappropriate basis sets. The different chapters introduce local orbitals and orbital localization as well as Slater-type orbitals and review basis sets for special applications, such as those for correlated methods, solid-state calculations, heavy atoms and time-dependent adaptable Gaussian bases for quantum dynamics simulations. This detailed review of the purpose of basis sets, their design, applications, possible problems and available solutions provides graduate students and beginning researchers with information not easily obtained from the available textbooks and offers valuable supporting material for any quantum chemistry or computational chemistry course at the graduate and/or undergraduate level. This book is also useful as a guide for researchers who are new to computational chemistry but are willing to extend their research tools by applying such methods.
Download or read book Modern Electronic Structure Theory written by D. R. Yarkony and published by World Scientific. This book was released on 1995 with total page 785 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern Electronic Structure Theory provides a didactically oriented description of the latest computational techniques in electronic structure theory and their impact in several areas of chemistry. The book is aimed at first year graduate students or college seniors considering graduate study in computational chemistry, or researchers who wish to acquire a wider knowledge of this field.
Download or read book Course of Lectures on Symmetry and Group Theory written by Taghreed Hashim Al-Noor and published by . This book was released on 2013-06-20 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Symmetry is central to spectroscopy, chemical bonding theory and many other aspects of the molecular sciences.Hopefully this course has given you a reasonable introduction to the qualitative description of molecular symmetry, and also to the way in which it can be used quantitatively within the context of group theory to predict important molecular properties.These main things you should have learnt in this course are:1. How to identify the symmetry elements possessed by a molecule and assign it to a point group.2. The consequences of symmetry for chirality and polarity of molecules.3. The effect of applying two or more symmetry operations consecutively (group multiplication)4. How to construct a matrix representation of a group, starting from a suitable set of basis functions.5. How to determine the irreducible representations (irreps) spanned by a basis set, and construct symmetry adapted linear combinations (SALCs) of the original basis functions that transform as the irreps of the group.6. How to construct molecular orbitals by taking linear combinations of SALCs of the same symmetry species.7. How to determine the symmetries of the various modes of motion (translational, rotational and vibrational) of apolyatomic molecule, and the symmetries of individual vibrational modes.8- symmetry operations that are used to describe molecular structure.
Download or read book Advances in Quantum Chemistry written by John R. Sabin and published by Elsevier. This book was released on 2005-12-20 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Quantum Chemistry presents surveys of current developments in this rapidly developing field that falls between the historically established areas of mathematics, physics, chemistry, and biology. With invited reviews written by leading international researchers, each presenting new results, it provides a single vehicle for following progress in this interdisciplinary area. This volume continues the tradition with high quality and thorough reviews of various aspects of quantum chemistry. It contains a variety of topics that include an extended and in depth discussion on the calculation of analytical first derivatives of the energy in a similarity transformed equation of motion couples cluster method.
Download or read book Broken orbital symmetry in excited and ionized states of molecu written by Harry Theo Jonkman and published by . This book was released on 19?? with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermophysical Properties of Materials written by G. Grimvall and published by Elsevier. This book was released on 1999-09-22 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a thoroughly revised version of the original book published in 1986. About half of the contents of the previous version remain essentially unchanged, and one quarter has been rewritten and updated. The rest consists of completely new and extended material. Recent research has focussed on new materials made through "molecular engineering", and computational materials science through ab initio electron structure calculations. Another trend is the ever growing interdisciplinary aspect of both basic and applied materials science. There is an obvious need for reviews that link well established results to the modern approaches. One purpose of this book is to provide such an overview in a specific field of materials science, namely thermophysical phenomena that are intimately connected with the lattice vibrations of solids. This includes, e.g., elastic properties and electrical and thermal transport. Furthermore, this book attempts to present the results in such a form that the reader can clearly see their domain of applicability, for instance if and how they depend on crystal structure, defects, applied pressure, crystal anisotropy etc. The level and presentation is such that the results can be immediately used in research. Graduate students in condensed matter physics, metallurgy, inorganic chemistry or geophysical materials will benefit from this book as will theoretical physicists and scientists in industrial research laboratories.
Download or read book Quantum Chemistry in the Age of Machine Learning written by Pavlo O. Dral and published by Elsevier. This book was released on 2022-09-16 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum chemistry is simulating atomistic systems according to the laws of quantum mechanics, and such simulations are essential for our understanding of the world and for technological progress. Machine learning revolutionizes quantum chemistry by increasing simulation speed and accuracy and obtaining new insights. However, for nonspecialists, learning about this vast field is a formidable challenge. Quantum Chemistry in the Age of Machine Learning covers this exciting field in detail, ranging from basic concepts to comprehensive methodological details to providing detailed codes and hands-on tutorials. Such an approach helps readers get a quick overview of existing techniques and provides an opportunity to learn the intricacies and inner workings of state-of-the-art methods. The book describes the underlying concepts of machine learning and quantum chemistry, machine learning potentials and learning of other quantum chemical properties, machine learning-improved quantum chemical methods, analysis of Big Data from simulations, and materials design with machine learning. Drawing on the expertise of a team of specialist contributors, this book serves as a valuable guide for both aspiring beginners and specialists in this exciting field. Compiles advances of machine learning in quantum chemistry across different areas into a single resource Provides insights into the underlying concepts of machine learning techniques that are relevant to quantum chemistry Describes, in detail, the current state-of-the-art machine learning-based methods in quantum chemistry
Download or read book Molecular Quantum Mechanics written by Peter William Atkins and published by Oxford University Press, USA. This book was released on 1997 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Quantum Mechanics, an accessible introduction to the foundations of quantum chemistry, established itself as a classic as soon as the original best-selling edition appeared. This new third edition will ensure its place is maintained in the forefront of its field. Entirely rewritten to present the subject more clearly than ever before, this new edition includes two completely new chapters - one on computational techniques in quantum chemistry, and another on scattering theory. Most of the material on the calculations of electronic structure is entirely new,and the discussions in the second edition have been enhanced with more mathematical rigour. With 330 two-colour illustrations, numerous worked examples, in-text exercises, an extensive further information section, and a wide range of applications treated consistently, this will surely prove to be an invaluable book for all senior chemistry undergraduates.
Download or read book Finite Groups and Quantum Theory written by D. B. Chesnut and published by . This book was released on 1974 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global and Accurate Vibration Hamiltonians from High Resolution Molecular Spectroscopy written by Michel Herman and published by . This book was released on 1999 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supercomputers in Chemistry written by Peter Lykos and published by . This book was released on 1981 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Journal of Chemical Physics written by and published by . This book was released on 1994 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:
