Author: Karl Blum
Publisher: Springer Science & Business Media
Published: 2013-06-29
Total Pages: 217
ISBN-13: 1461568080
DOWNLOAD EBOOK →Quantum mechanics has been mostly concerned with those states of systems that are represented by state vectors. In many cases, however, the system of interest is incompletely determined; for example, it may have no more than a certain probability of being in the precisely defined dynamical state characterized by a state vector. Because of this incomplete knowledge, a need for statistical averaging arises in the same sense as in classical physics. The density matrix was introduced by J. von Neumann in 1927 to describe statistical concepts in quantum mechanics. The main virtue of the density matrix is its analytical power in the construction of general formulas and in the proof of general theorems. The evaluation of averages and probabilities of the physical quantities characterizing a given system is extremely cumbersome without the use of density matrix techniques. The representation of quantum mechanical states by density matrices enables the maximum information available on the system to be expressed in a compact manner and hence avoids the introduction of unnecessary vari ables. The use of density matrix methods also has the advantage of providing a uniform treatment of all quantum mechanical states, whether they are completely or incom~'\etely known. Until recently the use of the density matrix method has been mainly restricted to statistical physics. In recent years, however, the application of the density matrix has been gaining more and more importance in many other fields of physics.
Author: Edwin D. Becker
Publisher: Elsevier
Published: 2012-12-02
Total Pages: 369
ISBN-13: 0323161855
DOWNLOAD EBOOK →High Resolution NMR: Theory and Chemical Applications discusses the principles and theory of nuclear magnetic resonance and how this concept is used in the chemical sciences. This book is written at an intermediate level, with mathematics used to augment verbal descriptions of the phenomena. This text pays attention to developing and interrelating four approaches – the steady state energy levels, the rotating vector picture, the density matrix, and the product operator formalism. The style of this book is based on the assumption that the reader has an acquaintance with the general principles of quantum mechanics, but no extensive background in quantum theory or proficiency in mathematics is required. This book begins with a description of the basic physics, together with a brief account of the historical development of the field. It looks at the study of NMR in liquids, including high resolution NMR in the solid state and the principles of NMR imaging and localized spectroscopy. This book is intended to assist chemistry graduate students, advanced undergraduate students, or researchers to understand NMR at a fundamental level. This text also provides illustrations of the applications of NMR to the determination of the structure of small organic molecules and macromolecules, including proteins.
Author: Sławomir Szymański
Publisher: Springer
Published: 2018-05-24
Total Pages: 402
ISBN-13: 3319907816
DOWNLOAD EBOOK →The book provides a detailed account of how condensed-phase molecular dynamics are reflected in the line shapes of NMR spectra. The theories establishing connections between random, time-dependent molecular processes and lineshape effects are exposed in depth. Special emphasis is placed on the theoretical aspects, involving in particular intermolecular processes in solution, and molecular symmetry issues. The Liouville super-operator formalism is briefly introduced and used wherever it is beneficial for the transparency of presentation. The proposed formal descriptions of the discussed problems are sufficiently detailed to be implemented on a computer. Practical applications of the theory in solid- and liquid-phase studies are illustrated with appropriate experimental examples, exposing the potential of the lineshape method in elucidating molecular dynamics NMR-observable molecular phenomena where quantization of the spatial nuclear degrees of freedom is crucial are addressed in the last part of the book. As an introduction to this exciting research field, selected aspects of the quantum mechanics of isolated systems undergoing rotational tunnelling are reviewed, together with some basic information about quantum systems interacting with their condensed environment. The quantum theory of rate processes evidenced in the NMR lineshapes of molecular rotors is presented, and illustrated with appropriate experimental examples from both solid- and liquid-phase spectra. In this context, the everlasting problem of the quantum-to-classical transition is discussed at a quantitative level. The book will be suitable for graduate students and new and practising researchers using NMR techniques.
Author: S.K. Sarkar
Publisher: Elsevier
Published: 1996-12-04
Total Pages: 387
ISBN-13: 9780080537597
DOWNLOAD EBOOK →NMR has become the most diverse spectroscopic tool available to date in biomedical research. It is now routinely used to study biomolecular structure and dynamics particularly as a result of recent developments of a cascade of highly sophisticated multidimensional NMR pulse sequences, and of advances in genetic engineering to produce biomolecules, uniformly or selectively enriched with 13C, 15N and 2H. Features of this book: • Provides an up-to-date treatment of NMR techniques and their application to problems of biomedical interest • Most refined multidimensional pulse sequences including the basic aspects are covered by leading NMR spectroscopists. The book will be useful to NMR spectroscopists, biochemists, and to molecular biologists interested in the use of NMR techniques for solving biological problems.
Author: John Cavanagh
Publisher: Elsevier
Published: 2010-07-21
Total Pages: 915
ISBN-13: 008047103X
DOWNLOAD EBOOK →Protein NMR Spectroscopy, Second Edition combines a comprehensive theoretical treatment of NMR spectroscopy with an extensive exposition of the experimental techniques applicable to proteins and other biological macromolecules in solution. Beginning with simple theoretical models and experimental techniques, the book develops the complete repertoire of theoretical principles and experimental techniques necessary for understanding and implementing the most sophisticated NMR experiments. Important new techniques and applications of NMR spectroscopy have emerged since the first edition of this extremely successful book was published in 1996. This updated version includes new sections describing measurement and use of residual dipolar coupling constants for structure determination, TROSY and deuterium labeling for application to large macromolecules, and experimental techniques for characterizing conformational dynamics. In addition, the treatments of instrumentation and signal acquisition, field gradients, multidimensional spectroscopy, and structure calculation are updated and enhanced. The book is written as a graduate-level textbook and will be of interest to biochemists, chemists, biophysicists, and structural biologists who utilize NMR spectroscopy or wish to understand the latest developments in this field. Provides an understanding of the theoretical principles important for biological NMR spectroscopy Demonstrates how to implement, optimize and troubleshoot modern multi-dimensional NMR experiments Allows for the capability of designing effective experimental protocols for investigations of protein structures and dynamics Includes a comprehensive set of example NMR spectra of ubiquitin provides a reference for validation of experimental methods
Author: Gh. D. Mateescu
Publisher: Prentice Hall
Published: 1993
Total Pages: 216
ISBN-13:
DOWNLOAD EBOOK →Offers an experimentally-based, clear explanation of the density-matrix and product operator treatments, thus allowing non-experts to work out sequences of varying degrees of complexity.