Ab Initio Variational Calculations of Molecular Vibrational-Rotational Spectra

Ab Initio Variational Calculations of Molecular Vibrational-Rotational Spectra
Author: Debra J. Searles
Publisher: Springer Science & Business Media
Total Pages: 245
Release: 2013-03-14
Genre: Science
ISBN: 3662055619

This work had its beginnings in the early 1980s at the University ofWollongong, with significant contributions from Dr. Margret Hamilton, Professors Peter G. Burton and Greg Doherty. The emphasis was to develop computer code to solve the nuclear Schrodinger problem. For bent triatomic molecules the project was fmally realized at the University of Newcastle a decade or so later, with the contribution from Ms. Feng Wan g. Aspects of this work are now taught in the quantum mechanics and electron spectroscopy courses at The University of Newcastle. Even now "complete" ab initio solutions of the time-independent SchrOdinger equation is not commonplace for molecules containing four atoms or more. In fact, when using the Eckart-Watson nuclear Hamiltonian a further restriction needs to be imposed; that is, the molecule is restricted to undergoing small amplitudes of vibration. This Hamiltonian is useful for molecules containing massive nuclei and moreover, has been extremely useful in interpreting the rovibrational spectra of small molecules. Nevertheless, a number of nuclear Hamiltonians that do not embed an equilibrium geometry have become well established and are extremely successful in interpreting rovibrational spectra of floppy molecules. Furthermore, solution algorithms vary greatly from research group to research group and it is still unclear which aspects will survive the next decade. For example, even for a triatomic molecule a general form of a potential function has not yet been uncovered that will generally interpolate with accuracy and precision ab initio discrete surfaces.

Nonequilibrium Vibrational Kinetics

Nonequilibrium Vibrational Kinetics
Author: Mario Capitelli
Publisher: Springer Science & Business Media
Total Pages: 354
Release: 2012-12-06
Genre: Science
ISBN: 3642486150

This book is devoted to the systematic treatment of nonequi 1 ibrium vibrational kinetics in molecular systems. Particular emphasis is given to the vibrational excitation of diatomic molecules by low-energy electrons in a discharge and by IR photons in laser-pumped systems. The book follows the different steps of the introduction, redistribution, loss, and chemical conversion of the vibrational quanta, from the points of view of the overall kinetics and the dynamics of elementary processes. These two aspects are balanced in a multidisciplinary approach. The different chapters give the basic instruments (theoretical and experimental) which are needed to understand the ki netics of nonequilibrium systems. The book will introduce the reader to different areas such as plasmachemistry, laser chemistry, IR and Raman spectroscopy, and relaxation phenomena, emphasizing how the vibrational energy affects such research fields. The chapters dedicated to collisional dynamics involving vibrational excited molecules provide an introduc tion to the modern techniques uti 1 ized in the scattering theory of inelastic and reactive collisions. The extension of the vibrational kinetics to polyatomic mole cules, discussed in Chap. 10, is the natural bridge between coll ision and coll i sionless regimes. In conclusion, we hope that the approach followed in this book will stimulate the collaboration of researchers coming from different research fields, which are too often completely separate.