Enge Wang – författare

As physical science advances, theoretical simulations become increasingly reflective of realistic systems, and experimental observations become more precise and refined. Thus, going beyond the Born-Oppenheimer approximation is inevitable. This book bases its discussion of condensed matter physics on the Schrödinger equation, considering both nuclear and electronic degrees of freedom. Particular attention is given to two types of phenomena: those, such as nuclear quantum effects, for which the Born-Oppenheimer approximation, although applicable in principle, is progressively weakened in practice, and those that cannot be applied at all, such as phenomena exhibiting non-adiabatic effects. In practical systems, the full quantum nature of condensed matter, as emphasized in this book, cannot be overlooked when performing accurate simulations or measurements of material properties. This book offers state-of-the-art quantum theoretical and experimental methods, valuable for undergraduates, graduates, researchers, and industry professionals in fields such as physics, chemistry, materials science, energy, and environmental science.

This book provides a relatively complete introduction to the methods used in computational condensed matter. A wide range of electronic structure theories are introduced, including traditional quantum chemistry methods, density functional theory, many-body perturbation theory, and more. Molecular dynamics simulations are also discussed, with extensions to enhanced sampling and free-energy calculation techniques including umbrella sampling, meta-dynamics, integrated tempering sampling, etc. As a further extension beyond the standard Born-Oppenheimer molecular dynamics, some simulation techniques for the description of quantum nuclear effects are also covered, based on Feynman's path-integral representation of quantum mechanics. The book aims to help beginning graduate students to set up a framework of the concepts they should know before tackling the physical/chemical problems they will face in their research.

This book highlights the fundamentals for understanding the essential problems and latest progresses in basic water science. Water is the most abundant, fundamental and important matter in nature. Arguably it is also the material that human beings study the most but misunderstand the most. Compared with the environmental science and engineering research activities on water resources, water pollution and water usage closely related to social problems at the macro level, basic scientific research on water at the molecular level has just emerged, the impact of which is not fully recognized yet. This book is devoted to introducing some important advances in the field of basic water science in past decades, with a particular emphasis on recent results on water and the interactions between water and solid surfaces at the molecular level. Starting from introducing concepts and popular theoretical and experimental methods for basic water research, this book mainly focuses on the atomic composition, electronic structure, and physicochemical properties of water molecules, water clusters and water layers (including surface water layers and water surface layers), rules for water adsorption on metals, oxides, and other typical solid surfaces such as salt, as well as the microscopic processes and mechanisms of water diffusion, wetting, decomposition and phase transformations under a variety of conditions. It is a good reference book for students and researchers in water-related science.