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The hydrogen bond represents an important interaction between molecules, and the dynamics of hydrogen bonds in water create an ever-present question associated with the process of chemical and biological reactions. In spite of numerous studies, the process remains poorly understood at the microscopic level because hydrogen-bond dynamics, such as bond rearrangements and hydrogen/proton transfer reactions, are extremely difficult to probe. Those studies have been carried out by means of spectroscopic methods where the signal stems from the ensemble of a system and the hydrogen-bond dynamics were inferred indirectly. This book addresses the direct imaging of hydrogen-bond dynamics within water-based model systems assembled on a metal surface, using a scanning tunneling microscope (STM). The dynamics of individual hydrogen bonds in water clusters, hydroxyl clusters, and water-hydroxyl complexes are investigated in conjunction with density functional theory. In these model systems, quantum dynamics of hydrogen bonds, such as tunneling and zero-point nuclear motion, are observed in real space. Most notably, hydrogen atom relay reactions, which are frequently invoked across many fields of chemistry, are visualized and controlled by STM. This work presents a means of studying hydrogen-bond dynamics at the single-molecule level, providing an important contribution to wide fields beyond surface chemistry.

Physicochemistry --- Chemical structure --- spectra (chemie) --- H (waterstof) --- moleculaire structuur --- fysicochemie

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Many types of stars show conspicuous emission lines in their optical spectra. These stars are broadly referred to as emission line stars. Emission line stars are attractive to many people because of their spectacular phenomena and their variability. The Astrophysics of Emission Line Stars offers general information on emission line stars, starting from a brief introduction to stellar astrophysics, and then moving toward a broad overview of emission line stars including early and late type stars as well as pre-main sequence stars. Detailed references have been prepared along with an index for further reading.

Physics. --- Astrophysics and Astroparticles. --- Astronomy, Observations and Techniques. --- Physique --- Emission spectroscopy. --- Science. --- Stars -- Constitution. --- Stars -- Spectra. --- Stars --- Emission spectroscopy --- Astrophysics --- Astronomy & Astrophysics --- Physical Sciences & Mathematics --- Spectra --- Spectra. --- Spectroscopy, Emission --- Spectrum of the stars --- Stellar spectra --- Atomic spectroscopy --- Molecular spectroscopy --- Spectrum analysis --- Astrophysics. --- Observations, Astronomical. --- Astronomy—Observations. --- Astronomical observations --- Observations, Astronomical --- Astronomical physics --- Astronomy --- Cosmic physics --- Physics

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In twenty-first century science, computational modelling is a powerful tool for the study of matter on a nanoscale. It complements an increasing range of experimental probes providing new or more accurate measurements in nanoscience and nanotechnology. The theoretical apparatus upon which electronic structure models are built determines their computational tractability which in turn determines their utility in applications to systems of increasing complexity. The accurate description of the effects of electron correlation is of central importance in ab initio electronic structure theory of atomic and molecular systems. Many body methods, in particular many-body perturbation theory and various coupled cluster expansions, are firmly established as the methods of choice in calculating electron correlation energies. Second order, Moeller-Plesset perturbation theory is the most widely used ab initio quantum chemical technique. Coupled cluster theory with single and double excitations and a perturbative estimate of the contribution of triple excitations is often regarded as a best compromise of accuracy and computational tractability. Both of these methods employ a single reference formalism which is not adequate for studies of systems involving significant quasidegeneracy effects such as bond breaking and bond making. Such studies require the use of a multireference formalism. However, the usual approach to the many-body multireference problem based on the Rayleigh-Schrödinger formalism suffers from the appearance of ˜intruder states' which can destroy the utility of the method. For more than thirty years a robust approach to the mulitreference correlation problem has been lacking. The little used Brillouin-Wigner formalism shows considerable potential in that it avoids `intruder states'. This volume brings together in a single volume recent leading edge research developments in this area. Brillouin-Wigner Methods for Many-Body Systems provides an introduction to many-body methods in electronic structure theory for the graduate student and post-doctoral researcher. It provides the researcher in many-body physics and theoretical chemistry with an account of Brillouin-Wigner methodology as it has been developed in recent years to handle the multireference correlation problem and defines the frontiers of this research field. This volume is of interest to atomic and molecular physicists, physical chemists and chemical physicists, quantum chemists and condensed matter theorists, computational chemists and applied mathematicians. --------------------------------------------------------------------------------------------------------------------- "This book on "Brillouin-Wigner methods for many-body systems" by Hubac and Wilson is perhaps the first comprehensive treatise on the subject. The authors are both internationally recognised experts in the field and are to be congratulated on their clear and thorough presentation of the present 'state of the art'. I recommend the book to anyone working in the field." (Roy McWeeny, Emeritus Professor, University of Pisa, Iyaly) "I strongly recommend the book by Professors Hubac and Wilson on Brillouin-Wigner Perturbation Theory. From their masterly introduction to the most technical details, this book will be an inspiration to anyone interested in the use of modern perturbation theory in theoretical chemistry and physics." (Henry F. Schaefer III, Graham Perdue Professor of Chemistry and Director of the Center for Computational Quantum Chemistry, University of Georgia, USA) "The book of I.Hubac and S.Wilson is very comprehensive.What is particularly interesting is a new fresh look on intruder state problem. Any serious student of Brillouin Wigner theory applied for many body systems should read this book." (J. Cízek, Emeritus Professor, University of Waterloo,Canada) "Ever since the introduction of the Brillouin-Wigner version of the coupled-cluster method by Hubac and Neogrady in 1994, there has been a conspicuous attention paid to this approach, particularly by the Slovak and Czech quantum chemistry schools. Although lacking the exact size-extensive property, its attractiveness stems primarily from its ability to overcome the problems of intruder states that often plague standard multireference approaches. It is commendable that the authors gathered in this monograph the relevant up to date developments in this field of endeavour. The book will undoubtedly be very much appreciated by both students and practitioners dealing with molecular electronic structure calculations." (Josef Paldus, Distinguished Professor Emeritus, University of Waterloo, Canada)

Chemical structure --- Chemistry --- Molecular biology --- Computer. Automation --- spectra (chemie) --- moleculaire structuur --- chemie --- informatica --- atoomstructuur

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Rasmus Brogaard's thesis digs into the fundamental issue of how the shape of a molecules relates to its photochemical reactivity. This relation is drastically different from that of ground-state chemistry, since lifetimes of excited states are often comparable to or even shorter than the time scales of conformational changes. Combining theoretical and experimental efforts in femto-second time-resolved photoionization Rasmus Brogaard finds that a requirement for an efficient photochemical reaction is the prearrangement of the constituents in a reactive conformation. Furthermore, he is able to show that by exploiting a strong ionic interaction between two chromophores, a coherent molecular motion can be induced and probed in real-time. This way of using bichromophoric interactions provides a promising strategy for future research on conformational dynamics.

Optics. Quantum optics --- Physicochemistry --- Chemical structure --- Theoretical spectroscopy. Spectroscopic techniques --- spectra (chemie) --- moleculaire structuur --- spectroscopie --- fysicochemie --- spectrometrie

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This book features tutorial-like chapters on ultrafast intense laser science by world-leading scientists who are active in the rapidly developing interdisciplinary research field. It is written to give a comprehensive survey of all the essential aspects of ultrafast intense laser science. The volume covers theories of atoms and molecules in intense laser fields, high intensity physics scaled to long wavelength, pulse shaping techniques, non-linear optics in the XUV region, ultrafast X-ray spectroscopy, quantum emission and applications, filamentation, and ultraintense-laser matter interaction.

Optics. Quantum optics --- Physicochemistry --- Chemical structure --- General biophysics --- spectra (chemie) --- moleculaire structuur --- biofysica --- quantumchemie --- lasers (technologie) --- elektrodynamica --- licht --- moleculaire biologie --- fysicochemie --- optica