Ideas of Quantum Chemistry, Volume Two: Interactions highlights the motions and systems in quantum chemistry and the models and tools used to assess them, thus giving detailed insights into the behaviors underlying quantum chemistry. Using an innovative structure to show the logical relationships between different topics, systems and methods, it answers questions and emphasizes knowledge using practical examples. Beginning with a review of the orbital model of electronic motion in periodic systems, the book goes on to explore the correlation of electronic motions, density functional theory (DFT), electric and magnetic fields, intermolecular interactions, chemical reactions and information processing. This third release has been updated and revised to cover the latest developments in the field. It can be used on its own as a guide to key interactions and tools or in combination with Volume Two to give a complete overview of the field. Features a practical range of quantum chemical problems throughout to support further understanding of interactions - Uses informal language and unique structure to make complex topics accessible - Includes new sections on Electronic Currents, Electron Autocorrelation and Spintronics Accessible guide to both foundational concepts and complex problems in the field of quantum chemistry Professor Piela received his bachelor degree in 1960 from the histroric Konarski College in his home town of Rzeszow, Poland. In 1965, he graduated with a Masters of Science from the University of Warsaw and, after obtaining his Ph.D. from the same university 5 years later, went on to became a professor in 1976. In addition to his work in Warsaw, he has carried out research in the Centre Européen de Calcul Atomique et Moléculaire (France), Facultés Universitaires de Namur (Belgium) and Cornell University (USA). In addition to being the author of about hundred papers published in international journals, Professor Piela is an elected member of the Academie Royale des Sciences, Lettres et Beaux-Arts de Belgique, and a member of the European Academy of Sciences.