The aim of this book is to give a comprehensive treatment of the different methods for the construction of spin eigenfunctions and to show their interrelations. The ultimate goal is the construction of an antisymmetric many-electron wave function that has both spatial and spin parts and the calculation of the matrix elements of the Hamiltonian over the total wave function. The representations of the symmetric group playa central role both in the construction of spin functions and in the calculation of the matrix elements of the Hamiltonian, so this subject will be treated in detail. We shall restrict the treatment to spin-independent Hamiltonians; in this case the spin does not have a direct role in the energy expression, but the choice of spin functions influences the form of spatial functions through the antisymmetry principle; the spatial functions determine the energy of the system. We shall also present the "spin-free quantum chemistry" approach of Matsen and co-workers, in which one starts immediately with the construction of spatial functions that have the correct permutational symmetries. By presenting both the conventional and the spin-free approach, one gains a better understanding of certain aspects of the elec tronic correlation problem. The latest advance in the calculation of the matrix elements of the Hamiltonian is the use of the representations of the unitary group, so this will be the last subject. It is a pleasant task to thank all those who helped in writing this book.

The author wrote a monograph 20 years ago on the construction of spin eigen functions; the monograph was published by Plenum. The aim of that mono graph was to present all aspects connected with the construction of spin eigen functions and its relation to the use of many-electron antisymmetric wavefunc tions. The present book is an introduction to these subjects, with an emphasis on the practical side. After the theoretical treatment, there will be many exam ples and exercises which will illustrate the different methods. The theory of the symmetric group and its representations generated by the different spin eigen functions is an other subject, this is closely related to the quantum chemical applications. Finally we will survey the calculation of the matrix elements of the Hamiltonian, using the different constructions of the spin functions. The closing chapter will deal with a new method that gained much importance recently; the spin-coupled valence bond method. Since the publication of Spin Eigenfunctions, nearly 20 years ago there have been many interesting developments in the subject; there are quite a few new algorithms for the construction of spin eigenfunctions. Moreover the use of the spin-coupled valence bond method showed the importance of using different constructions for the spin functions. The subject matter of this book has been presented in a graduate course in the Technion. The author is obliged to the graduate students Averbukh Vitali, Gokhberg Kirill, and Narevicius Edvardas for many helpful comments.

This is the first book to provide comprehensive treatment of the use of the symmetric group in quantum chemical structures of atoms, molecules, and solids. It begins with the conventional Slater determinant approach and proceeds to the basics of the symmetric group and the construction of spin eigenfunctions. The heart of the book is in the chapter dealing with spin-free quantum chemistry showing the great interpretation value of this method. The last three chapters include the unitary group approach, the symmetric group approach, and the spin-coupled valence bond method. An extensive bibliography concludes the book.

These two volumes collect thirty-eight selected papers from the scientific contributions presented at the Fourth European Workshop on Quantum Systems in Chemistry and Physics (QSCP-IV), held in Marly-le-Roi (France) in April 22-27, 1999, A total ofone hundred and fifteen scientists attended the workshop, 99 from Europe and 16 from the rest ofthe world. They discussed the state of the art, new trends, and future evolution of the methods and applications. The workshop was held in the old town of Marly-le-Roi, which lies to the West of Paris between the historic centres of Saint-Germain-en-Laye and Versailles. Participants were housed at the National Youth Institute, where over sixty lectures were given by l- ding members ofthe scientific community; in addition, over sixty posters were presented in two very animated sessions. We are grateful to the oral speakers and to the poster p- senters for making the workshop such an stimulating experience. The social programme was also memorable - and notjust for the closing banquet, which was held at the French Senate House. We are sure that participants will long remember their visit to the 'Musée des Antiquités Nationales': created by Napoleon III at the birthplace ofLouis XIV, this museum boasts one ofthe world finest collections ofarcheological artifacts. The Marly-le-Roi workshop followed the format established at the three previous meetings, organized by Prof.

The opportunity to present the physics of radioactive processes in some detail apart from topics such as instrumentation which conventionally compete with it for spacer is most welcome. The material is intended to give a fairly complete introduction to radiation physics to those who which to have more than a descriptive understanding of the subject. Although it is possible to work one’s way through much of the subject matter without having any previous physics background, some prior acquaintance with modern physics is desirable. A familiarity with calculus and differential equations is also assumed. Volume I begins with a brief description of classical physics, it’s extension to special relativity and quantum mechanics, and an introduction to basic atomic and nuclear concepts. A thorough discussion of atomic structure follows with emphasis on the theory of the multielectron atom, characteristic X-rays, and the Auger effect. Volume II treats the subjects of nuclear structure, nuclear decay processes, the interaction of radiation with matter, and the mathematics of radioactive decay.

Since 1983 I have been delivering lectures at Budapest University that are mainly attended by chemistry students who have already studied quantum chem istry in the amount required by the (undergraduate) chemistry curriculum of the University, and wish to acquire deeper insight in the field, possibly in prepara tion of a master's or Ph.D. thesis in theoretical chemistry. In such a situation, I have the freedom to discuss, in detail, a limited number of topics which I feel are important for one reason or another. The exact coverage may vary from year to year, but I usually concentrate on the general principles and theorems and other basic theoretical results which I foresee will retain their importance despite the rapid development of quantum chemistry. I commonly organize my lectures by treating the subject from the begin ning, without referring explicitly to any actual previous knowledge in quantum chemistry-only some familiarity with its goals, approaches and, to a lesser ex tent, techniques is supposed. I concentrate on the formulae and their derivation, assuming the audience essentially understands the reasons for deriving these results. This book is basically derived from the material of my lectures. The spe cial feature, distinguishing it from most other textbooks, is that all results are explicitly proved or derived, and the derivations are presented completely, step by step. True understanding of a theoretical result can be achieved only if one has gone through its derivation.

Linus Pauling wrote a stellar series of over 800 scientific papers spanning an amazing range of fields, some of which he himself initiated. This book is a selection of the most important of his writings in the fields of quantum mechanics, chemical bonding (covalent, ionic, metallic, and hydrogen bonding), molecular rotation and entropy, protein structure, hemoglobin, molecular disease, molecular evolution, the antibody mechanism, the molecular basis of anesthesia, orthomolecular medicine, radiation chemistry?biology, and nuclear structure. Through these papers the reader gets a fresh, unfiltered view of the genius of Pauling's many contributions to chemistry, chemical physics, molecular biology, and molecular medicine.

Linus Pauling wrote a stellar series of over 800 scientific papers spanning an amazing range of fields, some of which he himself initiated. This book is a selection of the most important of his writings in the fields of quantum mechanics, chemical bonding (covalent, ionic, metallic, and hydrogen bonding), molecular rotation and entropy, protein structure, hemoglobin, molecular disease, molecular evolution, the antibody mechanism, the molecular basis of anesthesia, orthomolecular medicine, radiation chemistry/biology, and nuclear structure. Through these papers the reader gets a fresh, unfiltered view of the genius of Pauling's many contributions to chemistry, chemical physics, molecular biology, and molecular medicine.

Advances in Atomic and Molecular Physics