It is widely recognized nowadays that conical intersections ofmolecular potential-energy surfaces play a key mechanistic role in thespectroscopy of polyatomic molecules, photochemistry and chemicalkinetics. This invaluable book presents a systematic exposition of thecurrent state of knowledge about conical intersections, which has beenelaborated in research papers scattered throughout the chemicalphysics literature.

It is widely recognized nowadays that conical intersections of molecular potential-energy surfaces play a key mechanistic role in the spectroscopy of polyatomic molecules, photochemistry and chemical kinetics. This invaluable book presents a systematic exposition of the current state of knowledge about conical intersections, which has been elaborated in research papers scattered throughout the chemical physics literature.Section I of the book provides a comprehensive analysis of the electronic-structure aspects of conical intersections. Section II shows the importance of conical intersections in chemical reaction dynamics and gives an overview of the computational techniques employed to describe the dynamics at conical intersections. Finally, Section III deals with the role of conical intersections in the fields of molecular spectroscopy and laser control of chemical reaction dynamics.This book has been selected for coverage in:• CC / Physical, Chemical & Earth Sciences• Chemistry Citation Index(tm)• Index to Scientific Book Contents® (ISBC)

The concept of adiabatic electronic potential-energy surfaces, defined by the Born?Oppenheimer approximation, is fundamental to our thinking about chemical processes. Recent computational as well as experimental studies have produced ample evidence that the so-called conical intersections of electronic energy surfaces, predicted by von Neumann and Wigner in 1929, are the rule rather than the exception in polyatomic molecules. It is nowadays increasingly recognized that conical intersections play a key mechanistic role in chemical reaction dynamics. This volume provides an up-to-date overview of the multi-faceted research on the role of conical intersections in photochemistry and photobiology, including basic theoretical concepts, novel computational strategies as well as innovative experiments. The contents and discussions will be of value to advanced students and researchers in photochemistry, molecular spectroscopy and related areas.

This book focuses on current applications of molecular quantum dynamics. Examples from all main subjects in the field, presented by the internationally renowned experts, illustrate the importance of the domain. Recent success in helping to understand experimental observations in fields like heterogeneous catalysis, photochemistry, reactive scattering, optical spectroscopy, or femto- and attosecond chemistry and spectroscopy underline that nuclear quantum mechanical effects affect many areas of chemical and physical research. In contrast to standard quantum chemistry calculations, where the nuclei are treated classically, molecular quantum dynamics can cover quantum mechanical effects in their motion. Many examples, ranging from fundamental to applied problems, are known today that are impacted by nuclear quantum mechanical effects, including phenomena like tunneling, zero point energy effects, or non-adiabatic transitions. Being important to correctly understand many observations in chemical, organic and biological systems, or for the understanding of molecular spectroscopy, the range of applications covered in this book comprises broad areas of science: from astrophysics and the physics and chemistry of the atmosphere, over elementary processes in chemistry, to biological processes (such as the first steps of photosynthesis or vision). Nevertheless, many researchers refrain from entering this domain. The book "Molecular Quantum Dynamics" offers them an accessible introduction. Although the calculation of large systems still presents a challenge - despite the considerable power of modern computers - new strategies have been developed to extend the studies to systems of increasing size. Such strategies are presented after a brief overview of the historical background. Strong emphasis is put on an educational presentation of the fundamental concepts, so that the reader can inform himself about the most important concepts, like eigenstates, wave packets, quantum mechanical resonances, entanglement, etc. The chosen examples highlight that high-level experiments and theory need to work closely together. This book thus is a must-read both for researchers working experimentally or theoretically in the concerned fields, and generally for anyone interested in the exciting world of molecular quantum dynamics.

Pt. I. Fundamental aspects and electronic structure. 1. Conical intersections in organic photochemistry / M.A. Robb. 2. Efficient excited-state deactivation in organic chromophores and biologically relevant molecules: role of electron and proton transfer processes / A.L. Sobolewski and W. Domcke. 3. Three-state conical intersections / S. Matsika. 4. Spin-orbit vibronic coupling in Jahn-Teller systems / L.V. Poluyanov and W. Domcke. 5. Symmetry analysis of geometric-phase effects in quantum dynamics / S.C. Althorpe -- pt. II. Dynamics at conical intersections. 6. Conical intersections in electron photodetachment spectroscopy: theory and applications / M.S. Schuurman and D.R. Yarkony. 7. Multistate vibronic dynamics and multiple conical intersections / S. Faraji, S. Gomez-Carrasco and H. Koppel. 8. Conical intersections coupled to an environment / I. Burghardt [und weitere]. 9. Ab initio multiple spawning: first principles dynamics around conical intersections / S. Yang and T.J. Martinez. 10. Non-Born-Oppenheimer molecular dynamics for conical intersections, avoided crossings, and weak interactions / A.W. Jasper and D.G. Truhlar. 11. Computational and methodological elements for nonadiabatic trajectory dynamics simulations of molecules / M. Barbatti, R. Shepard and H. Lischka. 12. Nonadiabatic trajectory calculations with ab initio and semiempirical methods / E. Fabiano [und weitere]. 13. Multistate nonadiabatic dynamics "on the fly" in complex systems and its control by laser fields / R. Mitric, J. Petersen and V. Bonacic-Koutecky. 14. Laser control of ultrafast dynamics at conical intersections / Y. Ohtsuki and W. Domcke -- pt. III. Experimental detection of dynamics at conical intersections. 15. Exploring nuclear motion through conical intersections in the UV photodissociation of azoles, phenols and related systems / T.A.A. Oliver [und weitere]. 16. Interrogation of nonadiabatic molecular dynamics via time-resolved photoelectron spectroscopy / M.S. Schuurman and A. Stolow. 17. Pump-probe spectroscopy of ultrafast vibronic dynamics in organic chromophores / N.K. Schwalb [und weitere]. 18. Femtosecond pump-probe polarization spectroscopy of vibronic dynamics at conical intersections and funnels / W.K. Peters, E.R. Smith and D.M. Jonas

Since the early 20th century, X-ray and electron scattering has provided a powerful means by which the location of atoms can be identified in gas-phase molecules and condensed matter with sub-atomic spatial resolution. Scattering techniques can also provide valuable observables of the fundamental properties of electrons in matter such as an electron’s spin and its energy. In recent years, significant technological developments in both X-ray and electron scattering have paved the way to time-resolved analogues capable of capturing real-time snapshots of transient structures undergoing a photochemical reaction. Structural Dynamics with X-ray and Electron Scattering is a two-part book that firstly introduces the fundamental background to scattering theory and photochemical phenomena of interest. The second part discusses the latest advances and research results from the application of ultrafast scattering techniques to imaging the structure and dynamics of gas-phase molecules and condensed matter. This book aims to provide a unifying platform for X-ray and electron scattering.

Computational spectroscopy is a rapidly evolving field that is becoming a versatile and widespread tool for the assignment of experimental spectra and their interpretation as related to chemical physical effects. This book is devoted to the most significant methodological contributions in the field, and to the computation of IR, UV-VIS, NMR and EPR spectral parameters with reference to the underlying vibronic and environmental effects. Each section starts with a chapter written by an experimental spectroscopist dealing with present challenges in the different fields; comprehensive coverage of conventional and advanced spectroscopic techniques is provided by means of dedicated chapters written by experts. Computational chemists, analytical chemists and spectroscopists, physicists, materials scientists, and graduate students will benefit from this thorough resource.