This volume is the outgrowth of a workshop held in October, 2000 at the Institute for Theoretical Atomic and Molecular Physics at the Harvard- Smithsonian Center for Astrophysics in Cambridge, MA. The aim of this book (similar in theme to the workshop) is to present an overview of new directions in antimatter physics and chemistry research. The emphasis is on positron and positronium interactions both with themselves and with ordinary matter. The timeliness of this subject comes from several considerations. New concepts for intense positron sources and the development of positron accumulators and trap-based positron beams provide qualitatively new experimental capabilities. On the theoretical side, the ability to model complex systems and complex processes has increased dramatically in recent years, due in part to progress in computational physics. There are presently an intriguing variety of phenomena that await theoretical explanation. It is virtually assured that the new experimental capabilities in this area will lead to a rapid expansion of this list. This book is organized into four sections: The first section discusses potential new experimental capabilities and the uses and the progress that might be made with them. The second section discusses topics involving antihydrogen and many-body phenomena, including Bose condensation of positronium atoms and positron interactions with materials. The final two sections treat a range of topics involving positron and positronium interactions with atoms and molecules.

With the exception of positron emission tomography (PET), the field of low energy positron science produces relatively few academic articles each year compared to more accessible fields. Though much has been achieved since the publication of two related volumes earlier in this series: Positron Solid State Physics (1981) and Positron Spectroscopy of Solids (1993), only the first steps have been made towards 'physics with many positrons': physical situations where the interactions of positrons with positrons can be observed. This 2009 "Enrico Fermi School" aims to stimulate the field o.

Per-Olov Löwdin's stature has been a symbol of the world of quantum theory during the past five decades, through his basic contributions to the development of the conceptual framework of Quantum Chemistry and introduction of the fundamental concepts; through a staggering number of regular summer schools, winter institutes, innumerable lectures at Uppsala, Gainesville and elsewhere, and Sanibel Symposia; by founding the International Journal of Quantum Chemistry and Advances in Quantum Chemistry; and through his vision of the possible and his optimism for the future, which has inspired generations of physicists, chemists, mathematicians, and biologists to devote their lives to molecular electronic theory and dynamics, solid state, and quantum biology. Fundamental World of Quantum Chemistry: Volumes I, II and III form a collection of papers dedicated to the memory of Per-Olov Löwdin. These volumes are of interest to a broad audience of quantum, theoretical, physical, biological, and computational chemists; atomic, molecular, and condensed matter physicists; biophysicists; mathematicians working in many-body theory; and historians and philosophers of natural science. The volumes will be accessible to all levels, from students, PhD students, and postdocs to their supervisors.

A comprehensive description of the principles and applications of positron and positronium chemistry. Pedagogical and tutorial in nature, it should be useful for graduate students and researchers in positron annihilation spectroscopy. The contributors are scientists in the frontiers of research.

This book provides a comprehensive description of the principles and applications of positron and positronium chemistry. Pedagogical and tutorial in nature, it will be ideal for graduate students and researchers in the area of positron annihilation spectroscopy. The contributing authors are authoritative scientists prominent in the frontiers of research, actively pursuing positron annihilation research on chemical and applied systems.

Commencing with a self-contained overview of atomic collision theory, this monograph presents recent developments of R-matrix theory and its applications to a wide-range of atomic molecular and optical processes. These developments include the electron and photon collisions with atoms, ions and molecules which are required in the analysis of laboratory and astrophysical plasmas, multiphoton processes required in the analysis of superintense laser interactions with atoms and molecules and positron collisions with atoms and molecules required in antimatter studies of scientific and technologial importance. Basic mathematical results and general and widely used R-matrix computer programs are summarized in the appendices.

Advances in Quantum Chemical Topology Beyond QTAIM provides a complete overview of the field, starting with traditional methods and then covering key steps to the latest state-of-the-art extensions of QTAIM. The book supports researchers by compiling and reviewing key methods, comparing different algorithms, and providing computational results to show the efficacy of the approaches. Beginning with an introduction to quantum chemistry, QTAIM and key extensions, the book goes on to discuss interacting quantum atoms and related energy properties, explores partitioning methods, and compares algorithms for QTAIM. Partitioning schemes are them compared in more detail before applications are explored and future developments discussed. Drawing together the knowledge of key authorities in the area, this book provides a comprehensive, pedogeological guide to this insightful theory for all those interested in modelling, exploring and understanding molecular properties. - Provides a contemporary review of the extensions and application of QTAIM methods - Compiles all extensions of QTAIM in one place for easy reference - Includes a chapter with an Introduction to Quantum Chemistry - Presents complex information at a level accessible to those engaged in theoretical/computational chemistry