This book distills the knowledge gained from research into atoms in molecules over the last 10 years into a unique, handy reference. Throughout, the authors address a wide audience, such that this volume may equally be used as a textbook without compromising its research-oriented character. Clearly structured, the text begins with advances in theory before moving on to theoretical studies of chemical bonding and reactivity. There follow separate sections on solid state and surfaces as well as experimental electron densities, before finishing with applications in biological sciences and drug-design. The result is a must-have for physicochemists, chemists, physicists, spectroscopists and materials scientists.

The molecular structure hypothesis - that a molecule is a collection of atoms linked by a network of bonds - was forged in the crucible of nineteenth century experimental chemistry and has continued to serve as the principal means of ordering and classifying the observations of chemistry. There is a difficulty with the hypothesis, however, in that it is not related directly to the physics which governs the motions of the nuclei and electrons that make up the atoms and the bonds. It isthe purpose of this important book - now available in paperback for the first time - to show that a theory can be developed to underpin the molecular structure hypothesis - that the atoms in a molecule are real, with properties predicted and defined by the laws of quantum mechanics can be incorporated into the resulting theory - a theory of atoms in molecules. The book is aimed at those scientists responsible for performing the experiments and collecting the observations on the properties ofmatter at the atomic level, in the belief that the transformation of qualitative concepts into a qualitative theory will serve to deepen our understanding of chemistry.

This book is intended for physicists and chemists who need to understand the theory of atomic and molecular structure and processes, and who wish to apply the theory to practical problems. As far as practicable, the book provides a self-contained account of the theory of relativistic atomic and molecular structure, based on the accepted formalism of bound-state Quantum Electrodynamics. The author was elected a Fellow of the Royal Society of London in 1992.

Atoms in Molecules (AIM) is a powerful and novel theory for understanding chemistry, acting as a bridge between fundamental chemical concepts - such as the atom, the bond and molecular structure - and quantum mechanics. It is used increasingly in both theoretical and crystallographic research internationally, including its use in interpreting experimental charge densities. This book provides a balanced, consistent and didactic account of this exciting theory, explaining its potential impact and making it accessible to a wide audience.

The molecular structure hypothesis--the proposition that a molecule is a collection of atoms linked by a network of bonds--provides the principal means of ordering and classifying observations in chemistry. It is not, however, directly related to the physics which govern the motions of atomic nuclei and electrons. This important book develops a theory establishing that molecular structure--with properties predicted and defined by the laws of quantum mechanics--can be explained in terms of underlying physics. As a result, the classification based upon the concept of atoms in molecules is freed from its empirical constraints and the full predictive power of quantum mechanics can be incorporated into the resulting theory--a theory of atoms in molecules. Eminently accessible and readable, this unique book will interest all physical scientists who use the concepts of atoms, bonds, and structure in the interpretation of their work.

Atoms and Molecules describes the basic properties of atoms and molecules in terms of group theoretical methods in atomic and molecular physics. The book reviews mathematical concepts related to angular momentum properties, finite and continuous rotation groups, tensor operators, the Wigner-Eckart theorem, vector fields, and vector spherical harmonics. The text also explains quantum mechanics, including symmetry considerations, second quantization, density matrices, time-dependent, and time-independent approximation methods. The book explains atomic structure, particularly the Dirac equation in which its nonrelativistic approximation provides the basis for the derivation of the Hamiltonians for all important interactions, such as spin-orbit, external fields, hyperfine. Along with multielectron atoms, the text discusses multiplet theory, the Hartree-Fock formulation, as well as the electromagnetic radiation fields, their interactions with atoms in first and higher orders. The book explores molecules and complexes, including the Born-Oppenheimer approximation, molecular orbitals, the self-consistent field method, electronic states, vibrational and rotational states, molecular spectra, and the ligand field theory. The book can prove useful for graduate or advanced students and academicians in the field of general and applied physics.