Spectra And Dynamics Of Small Molecules

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.

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

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.

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.

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.