A modern, comprehensive text and reference describing intermolecular forces, this book begins with coverage of the concepts and methods for simpler systems, then moves on to more advanced subjects for complex systems – emphasizing concepts and methods used in calculations with realistic models and compared with empirical data. Contains applications to many physical systems and worked examples Proceeds from introductory material to advanced modern treatments Has relevance for new materials, biological phenomena, and energy and fuels production

The types of forces that are involved in the interactions between molecules vary across a wide spectrum from very strong, as in ion-ion interactions, to the much weaker forces that are involved in van der Waals complexes. This book provides an introduction to the theoretical methods that are used to analyze each sort of force and provide the reader with a guide to the most appropriate method for a given problem. Examples are used to illustrate the points, and the pitfalls that a novice might encounter are outlined. These examples range from very small complexes to much larger systems with biological relevance.

Recent developments in various areas of chemistry have been decisively influenced by the principles of structure and mechanism and by the ideas of coordination chemistry, in particular by the donor-acceptor approach, A unified view of almost all kinds of molecular forces is provided by quantum mechanics, and for practical purposes have been classified according to model assumptions, namely, dispersion, polarization, electrostatic, and short-range forces. The latter are divided into two- and three-center covalent chemical bonds, metallic bonds, and exchange-repulsion forces. This approach allows statements of principle and systematic analysis. However, quantitative predictions on concrete large systems are virtually impossible, and there are no general rules that account for structural and chemical changes due to intermolecular interactions. Chemists are therefore left with qualitative descriptions in which the changes in electron densities are considered. Such models as the MO theory or the resonance concept unrealistically assume that the nuclei remain in fixed positions. Further difficulties are encountered in the attempted description on the "nature" of the chemical bond, e.g., the forces involved. In order to avoid these difficulties an extension of the donor-acceptor concept, characterized by the comparison between equilibrium structures in different molecular environments, will be presented in this book. In this way, changes in the positions of the nuclei can be taken into account and the question of the nature of the molecular forces is no longer important.

The study of gases, clusters, liquids, and solids as units or systems, eventually focuses on the properties of these systems as governed by interactions between atoms, molecules, and radicals that are not covalently bonded to one another. The stereo/spatial properties of molecular species themselves are similarly controlled, with such interactions found throughout biological, polymeric, and cluster systems and are a central feature of chemical reactions. Nevertheless, these interactions are poorly described and characterized, with efforts to do so, usually based on a particular quantum or even classical mechanical procedure, obscuring the fundamental nature of the interactions in the process. Intra- and Intermolecular Interactions Between Noncovalently Bonded Species addresses this issue directly, defining the nature of the interactions and discussing how they should and should not be described. It reviews both theoretical developments and experimental procedures in order to explore interactions between nonbonded entities in such a fundamental manner as to elucidate their nature and origins. Drawing attention to the extensive experience of its editor and team of expert authors, Intra- and Intermolecular Interactions Between Noncovalently Bonded Species is an indispensable guide to the foundational knowledge, latest advances, most pressing challenges, and future directions for all those whose work is influenced by these interactions. - Comprehensively describes the nature of interactions between nonbonded species in biological systems, liquids, crystals, clusters, and in particular, water. - Combines fundamental, theoretical, background information based on various approximations with the knowledge of experimental techniques. - Outlines interactions clearly and consistently with a particular focus on frequency and time-resolved spectroscopies as applied to these interactions.

The subject of this book — intermolecular interactions — is as important in physics as in chemistry and molecular biology. Intermolecular interactions are responsible for the existence of liquids and solids in nature. They determine the physical and chemical properties of gases, liquids, and crystals, the stability of chemical complexes and biological compounds. In the first two chapters of this book, the detailed qualitative description of different types of intermolecular forces at large, intermediate and short-range distances is presented. For the first time in the monographic literature, the temperature dependence of the dispersion forces is discussed, and it is shown that at finite temperatures the famous Casimir-Polder asymptotic formula is correct only at narrow distance range. The author has aimed to make the presentation understandable to a broad scope of readers without oversimplification. In Chapter 3, the methods of quantitative calculation of the intermolecular interactions are discussed and modern achievements are presented. This chapter should be helpful for scientists performing computer calculations of many-electron systems. The last two chapters are devoted to the many-body effects and model potentials. More than 50 model potentials exploited for processing experimental data and computer simulation in different fields of physics, chemistry and molecular biology are represented. The widely used global optimisation methods: simulated annealing, diffusion equation method, basin-hopping algorithm, and genetic algorithm are described in detail. Significant efforts have been made to present the book in a self-sufficient way for readers. All the necessary mathematical apparatus, including vector and tensor calculus and the elements of the group theory, as well as the main methods used for quantal calculation of many-electron systems are presented in the appendices.

Electrical Interactions in Molecular Biophysics: An Introduction deals with electrical interactions between biomolecules and therefore encompasses two disciplines, molecular biology and physics. The emphasis is on the electrical nature of biochemical or molecular biological reactions. The principles of electrostatics are used to explain some of the basic units of structure on a molecular level. Comprised of nine chapters, this book opens with an overview of the concepts and structures of biochemistry, with particular reference to different structural biochemical groups and how they are used as building blocks in forming molecules. The following chapters discuss the basics of elementary electrostatics; dielectric constants and dipoles; the dipole moments of biomolecules; van der Waals forces; and Debye-Huckel theory. Water and water structure are also considered from a physical standpoint. The final chapter is devoted to experimental techniques that rely upon the electrical properties of biomolecules and explains what types of information can be obtained from each experimental form. This monograph will be of interest to students and practitioners in biochemistry, molecular biology, biophysics, or microbiology.