Rotational Spectroscopy Of Diatomic Molecules

The definitive text on the rotational spectroscopy of diatomic molecules.

The definitive text on the rotational spectroscopy of diatomic molecules.

Procedures are described, in this pedagogical monograph, for making quantum mechanical calculations of rotational energy levels and rotational line intensities in diatomic molecules. The procedures are illustrated by sample calculations.A familiarity with the material of this report should enable a practicing electronic spectroscropist to carry out, though in a rather mechanical way, his own theoretical calculations for molecules under experimental investigation.The material of this report is aimed at electronic spectroscopists who have had the equivalent of one semester of graduate-level quantum mechanics.(Author).

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

This book provides a fresh, photon‐based description of modern molecular spectroscopy and photophysics, with applications drawn from chemistry, biology, physics and materials science. The concise and detailed approach includes some of the most recent devel

Perturbations in the Spectra of Diatomic Molecules examines in sufficient detail the spectrum of every diatomic molecule. This book is divided into seven chapters. Chapter 1 describes the perturbations and simple procedures for evaluating matrix elements of angular momentum. The terms in the molecular Hamiltonian that are responsible for perturbations are elaborated in Chapter 2, while the process of reducing spectra to molecular constants and the difficulty of relating empirical parameters to terms in the exact molecular Hamiltonian are described in Chapter 3. Chapter 4 discusses the magnitudes and physical interpretations of matrix elements. The transition intensities, especially quantum mechanical interference effects, are reviewed in Chapter 5. The last two chapters are devoted to the two forms of perturbation—predissociation and autoionization. This publication is a good source for graduate students, theorists, experimentalists, and potential users of spectroscopic data.