Spectra and Dynamics of Small Molecules


Book Description

These seven lectures are intended to serve as an introduction for beginning graduate students to the spectra of small molecules. The author succeeds in illustrating the concepts by using language and metaphors that capture and elegantly convey simple insights into dynamics that lie beyond archival molecular constants. The lectures can simultaneously be viewed as a collection of interlocking special topics that have fascinated the author and his students over the years. Though neither a textbook nor a scholarly monograph, the book provides an illuminating perspective that will benefit students and researchers alike.




The Spectra and Dynamics of Diatomic Molecules


Book Description

This book is written for graduate students just beginning research, for theorists curious about what experimentalists actually can and do measure, and for experimentalists bewildered by theory. It is a guide for potential users of spectroscopic data, and uses language and concepts that bridge the frequency-and time-domain spectroscopic communities. Key topics, concepts, and techniques include: the assignment of simple spectra, basic experimental techniques, definition of Born-Oppenheimer and angular momentum basis sets and the associated spectroscopic energy level patterns (Hund's cases), construction of effective Hamiltonian matrices to represent both spectra and dynamics, terms neglected in the Born-Oppenheimer approximation (situations intermediate between Hund's cases, spectroscopic perturbations), nonlinear least squares fitting, calculation and interpretation of coupling terms, semi-classical (WKB) approximation, transition intensities and interference effects, direct photofragmentation (dissociation and ionization) and indirect photofragmentation (predissociation and autoionization) processes, visualization of intramolecular dynamics, quantum beats and wavepackets, treatment of decaying quasi-eigenstates using a complex Heff model, and concluding with some examples of polyatomic molecule dynamics. Students will discover that there is a fascinating world of cause-and-effect localized dynamics concealed beyond the reduction of spectra to archival molecular constants and the exact ab initio computation of molecular properties. Professional spectroscopists, kinetics, ab initio theorists will appreciate the practical, simplified-model, and rigorous theoretical approaches discussed in this book. - A fundamental reference for all spectra of small, gas-phase molecules - It is the most up-to-date and comprehensive book on the electronic spectroscopy and dynamics of diatomic molecules - The authors pioneered the development of many of the experimental methods, concepts, models, and computational schemes described in this book




Molecular Dynamics


Book Description

The latest developments in quantum and classical molecular dynamics, related techniques, and their applications to several fields of science and engineering. Molecular simulations include a broad range of methodologies such as Monte Carlo, Brownian dynamics, lattice dynamics, and molecular dynamics (MD).Features of this book:• Presents advances in methodologies, introduces quantum methods and lists new techniques for classical MD• Deals with complex systems: biomolecules, aqueous solutions, ice and clathrates, liquid crystals, polymers• Provides chemical reactions, interfaces, catalysis, surface phenomena and solidsAlthough the book is not formally divided into methods and applications, the chapters are arranged starting with those that discuss new algorithms, methods and techniques, followed by several important applications.




The Structure of Small Molecules and Ions


Book Description

The workshop on "The structure of small molecules and ions" was held at the Neve-Han guest house, near Jerusalem, Israel on December 13 to 18 in mem ory of the late Professor Itzhak Plesser. Professor Plesser played a central role in the research done both at the Weizmann Institute and at Argonne National Laboratories on the "Coulomb explosion" method. His friends honored his memory by organizing a meeting in which subjects related to Plesser's interests would be discussed. Just a week be fore the conference started we were struck by another tragedy -the death of our graduate student Ms. Hana Kovner, who participated in many of the Coulomb explosion experiments at the Weizmann Institute. We would like to dedicate these proceedings to her memory as well. The goal of the workshop was to bring together chemists and physicists working on different aspects of the structural problems of small molecular en tities. The time seemed appropriate for discussing experimental and theoretical concepts, since in recent years new methods have been introduced, and a large amount of information has been accumulated on systems not studied before, like unstable molecules, ions, van der Waals molecules and clusters. The program of the workshop reflects, we believe, these new developments. The meeting was characterized by intensive discussions in which the weak nesses and strengths of new and of well established concepts were revealed. We hope that it measured up to the high standards Itzhak Plesser maintained all through his scientific life.




Photodissociation Dynamics


Book Description

Photodissociation induced by the absorption of single photons permits the detailed study of molecular dynamics such as the breaking of bonds, internal energy transfer and radiationless transitions. The availability of powerful lasers operating over a wide frequency range has stimulated rapid development of new experimental techniques which make it possible to analyse photodissociation processes in unprecedented detail. This text elucidates the achievements in calculating photodissociation cross-sections and fragment state distributions from first principles, starting from multi-dimensional potential energy surfaces and the Schrödinger equation of nuclear motion. Following an extended introduction in which the various types of observables are outlined, the book summarises the basic theoretical tools, namely the time-independent and the time-dependent quantum mechanical approaches as well as the classical picture of photodissociation. The discussions of absorption spectra, diffuse vibrational structures, the vibrational and rotational state distributions of the photofragments form the core of the book. More specific topics such as the dissociation of vibrationally excited molecules, emission during dissociation, or nonadiabatic effects are also discussed. It will be of interest to graduate students and senior scientists working in molecular physics, spectroscopy, molecular collisions and molecular kinetics.




Vibrational Dynamics Of Molecules


Book Description

Vibrational Dynamics of Molecules represents the definitive concise text on the cutting-edge field of vibrational molecular chemistry. The chapter contributors are a Who's Who of world leaders in the field. The editor, Joel Bowman, is widely considered as one of the founding fathers of theoretical reaction dynamics. The included topics span the field, from fundamental theory such as collocation methods and vibrational CI methods, to interesting applications such as astrochemistry, supramolecular systems and virtual computational spectroscopy. This is a useful reference for theoretical chemists, spectroscopists, physicists, undergraduate and graduate students, lecturers and software developers.




Molecular Dynamics and Spectroscopy by Stimulated Emission Pumping


Book Description

Since the first stimulated emission pumping (SEP) experiments more than a decade ago, this technique has proven powerful for studying vibrationally excited molecules. SEP is now widely used by increasing numbers of research groups to investigate fundamental problems in spectroscopy, intramolecular dynamics, intermolecular interactions, and even reactions. SEP provides rotationally pre-selected spectra of vibrationally highly excited molecules undergoing large amplitude motions. A unique feature of SEP is the ability to access systematically a wide variety of extreme excitations localized in various parts of a molecule, and to prepare populations in specific, high vibrational levels. SEP has made it possible to ask and answer specific questions about intramolecular vibrational redistribution and the role of vibrational excitation in chemical reactions.




Molecular Spectroscopy and Quantum Dynamics


Book Description

Molecular Spectroscopy and Quantum Dynamics, an exciting new work edited by Professors Martin Quack and Roberto Marquardt, contains comprehensive information on the current state-of-the-art experimental and theoretical methods and techniques used to unravel ultra-fast phenomena in atoms, molecules and condensed matter, along with future perspectives on the field. - Contains new insights into the quantum dynamics and spectroscopy of electronic and nuclear motion - Presents the most recent developments in the detection and interpretation of ultra-fast phenomena - Includes a discussion of the importance of these phenomena for the understanding of chemical reaction dynamics and kinetics in relation to molecular spectra and structure




Stereodynamics of Molecular Systems


Book Description

Stereodynamics of Molecular Systems covers the proceedings of a symposium held at the State University of New York at Albany, on 23-24 April 1979. The book focuses on the stereodynamics of molecules and ions and nucleic acid structure. The contributions tackle spectroscopy, crystallography, perturbations, and electron-transfer reactions. The selection first offers information on nuclear magnetic resonance spectroscopy chemical shifts, coupling constants, and molecular geometry, including chemical shifts, bond coupling constants, and constitutional features of nucleic acids. The book then takes a look at nuclear magnetic resonance spectroscopy stereodynamics of small molecules; nuclear magnetic resonance spectroscopy solution dynamics of polymer chains; and single crystal crystallography. The publication evaluates the steric effects on electron-transfer reactions of sulfonamides; effects of isotopic perturbation on NMR spectra; and conformational mobility of the backbone of cyclic tripeptides. The book also discusses accessible surface areas of nucleic acids and their relation to folding, conformational transition, and protein recognition. Topics include polarity of exposed atoms, surface of DNA double helices, transfer RNA, and calculation of “static“ accessible surface area. The selection is a dependable reference for readers interested in the stereodynamics of molecules and ions and nucleic acid structure.




High Resolution Electronic Spectroscopy of Small Molecules


Book Description

Over recent years electronic spectroscopy has developed significantly, with key applications in atmospheric chemistry, astrophysics and astrochemistry. High Resolution Electronic Spectroscopy of Small Molecules explores both theoretical and experimental approaches to understanding the electronic spectra of small molecules, and explains how this information translates to practice. Professors Geoffrey Duxbury and Alexander Alijah present the links between spectroscopy and photochemistry, and discuss theoretical treatments of the interaction between different electronic states. They provide a thorough discussion of experimental techniques, and explore practical applications. This book will be an indispensable reference for graduate students and researchers in physics and chemistry working on theoretical and practical aspects of electronic spectra, as well as atmospheric scientists, photochemists, kineticists and professional spectroscopists.