This book aims to provide a detailed introduction to the state-of-the-art covariant density functional theory, which follows the Lorentz invariance from the very beginning and is able to describe nuclear many-body quantum systems microscopically and self-consistently. Covariant density functional theory was introduced in nuclear physics in the 1970s and has since been developed and used to describe the diversity of nuclear properties and phenomena with great success.In order to provide an advanced and updated textbook of covariant density functional theory for graduate students and nuclear physics researchers, this book summarizes the enormous amount of material that has accumulated in the field of covariant density functional theory over the last few decades as well as the latest developments in this area. Moreover, the book contains enough details for readers to follow the formalism and theoretical results, and provides exhaustive references to explore the research literature.

Density Functional Theory is a rapidly developing branch of many-particle physics that has found applications in atomic, molecular, solid-state and nuclear physics. This book describes the conceptual framework of density functional theory and discusses in detail the derivation of explicit functionals from first principles as well as their application to Coulomb systems. Both non-relativistic and relativistic systems are treated. The connection of density functional theory with other many-body methods is highlighted. The presentation is self-contained; the book is, thus, well suited for a graduate course on density functional theory.

This book summarizes the enormous amount of material accumulated in the field of nuclear density functional theory over the last few decades. The goal of the theory is to provide a complete quantum mechanical description and explanation of nuclear phenomena in terms of the local density distribution as a basic ingredient rather than the many particle wavefunction. This leads to a considerable reduction in the mathematical complexity of nuclear many-body problems and to a great conceptual simplicity and visual clarity in its theoretical treatment. The authors develop the mathematical framework on which the theory is based and consider the associated approaches used to analyze experimental data in a variety of nuclei and nuclear processes with widely differing properties.

Density Functional Theory (DFT) has firmly established itself as the workhorse for atomic-level simulations of condensed phases, pure or composite materials and quantum chemical systems. This work offers a rigorous and detailed introduction to the foundations of this theory, up to and including such advanced topics as orbital-dependent functionals as well as both time-dependent and relativistic DFT. Given the many ramifications of contemporary DFT, the text concentrates on the self-contained presentation of the basics of the most widely used DFT variants: this implies a thorough discussion of the corresponding existence theorems and effective single particle equations, as well as of key approximations utilized in implementations. The formal results are complemented by selected quantitative results, which primarily aim at illustrating the strengths and weaknesses of particular approaches or functionals. The structure and content of this book allow a tutorial and modular self-study approach: the reader will find that all concepts of many-body theory which are indispensable for the discussion of DFT - such as the single-particle Green's function or response functions - are introduced step by step, along with the actual DFT material. The same applies to basic notions of solid state theory, such as the Fermi surface of inhomogeneous, interacting systems. In fact, even the language of second quantization is introduced systematically in an Appendix for readers without formal training in many-body theory.

Energy density functional (EDF) approaches have become over the past twenty years a powerful framework to study the structure and reactions of atomic nuclei. This book gives an updated presentation of non-relativistic and covariant energy functionals, single- and multi-reference methods, and techniques to describe small- and large-amplitude collective motion or nuclei at high excitation energy. Edited by an expert in energy density functional theory, Dr Nicolas Schunck, alongside several experts within the field, this book provides a comprehensive and informative exploration of EDF methods. Detailed derivations, practical approaches, examples and figures are used throughout the book to give a coherent narrative of topics that have hitherto rarely been covered together.

Density functional methods form the basis of a diversified and very active area of present days computational atomic, molecular, solid state and even nuclear physics. A large number of computational physicists use these meth ods merely as a recipe, not reflecting too much upon their logical basis. One also observes, despite of their tremendeous success, a certain reservation in their acceptance on the part of the more theoretically oriented researchers in the above mentioned fields. On the other hand, in the seventies (Thomas Fermi theory) and in the eighties (Hohenberg-Kohn theory), density func tional concepts became subjects of mathematical physics. In 1994 a number of activities took place to celebrate the thirtieth an niversary of Hohenberg-Kohn-Sham theory. I took this an occassion to give lectures on density functional theory to senior students and postgraduates in the winter term of 1994, particularly focusing on the logical basis of the the ory. Preparing these lectures, the impression grew that, although there is a wealth of monographs and reviews in the literature devoted to density func tional theory, the focus is nearly always placed upon extending the practical applications of the theory and on the development of improved approxima tions. The logical foundadion of the theory is found somewhat scattered in the existing literature, and is not always satisfactorily presented. This situation led to the idea to prepare a printed version of the lecture notes, which resulted in the present text.

Quantal density functional theory (Q-DFT) is a new local effective potential energy theory of the electronic structure of matter. It is a description in terms of classical fields that pervade all space, and their quantal sources. The fields, which are explicitly defined, are separately representative of the many-body electron correlations present in such a description, namely, those due to the Pauli exclusion principle, Coulomb repulsion, correlation-kinetic, and correlation-current-density effects. The book further describes Schrödinger theory from the new perspective of fields and quantal sources. It also explains the physics underlying the functionals and functional derivatives of traditional DFT.

Time-dependent density-functional theory (TDDFT) is a quantum mechanical approach for the dynamical properties of electrons in matter. It's widely used in (bio)chemistry and physics to calculate molecular excitation energies and optical properties of materials. This is the first graduate-level text on the formal framework and applications of TDDFT.

This book is a rigorous, unified account of the fundamental principles of the density-functional theory of the electronic structure of matter and its applications to atoms and molecules. Containing a detailed discussion of the chemical potential and its derivatives, it provides an understanding of the concepts of electronegativity, hardness and softness, and chemical reactivity. Both the Hohenberg-Kohn-Sham and the Levy-Lieb derivations of the basic theorems are presented, and extensive references to the literature are included. Two introductory chapters and several appendices provide all the background material necessary beyond a knowledge of elementary quantum theory. The book is intended for physicists, chemists, and advanced students in chemistry.

The nuclear density functional theory (DFT) is a microscopic self-consistent framework suitable for describing heavy nuclei and performing large-scale studies. In this dissertation I discuss my research works on the development and application of the Skyrme nuclear-DFT framework, covering a broad range of topics, including the nucleon localization in rotating systems, the origin of reflection-asymmetric deformations, the parameter calibration for beta decays, and the development of a new coordinate-space DFT solver.The nucleon localization function (NLF), discussed in the first part, is a useful tool for the visualization of structure information. It has been utilized to characterize clustering and shell structure. How the NLF pattern evolves in rotating systems, how it visualizes internal nuclear structure, and how it is connected with single-particle (s.p.) orbits are discussed in this dissertation. The second part deals with nuclei having reflection-asymmetric shapes, which are important candidates for the search of permanent electric dipole moments. In this dissertation, the origin of pear-like deformation is investigated through both the multipole expansion of the energy density functional and the spectrum of canonical s.p. states. Theoretical predictions of beta-decay rates are discussed next; they are important for r-process simulations that involves nuclei whose experimental beta-decay data are unknown. To provide reliable predictions with quantified uncertainties, the Ï72 optimization is performed to constrain parameters that significantly affect beta-decay transitions in proton-neutron finite-amplitude-method calculations. Besides a well calibrated functional, a reliable and efficient DFT solver is also crucial. The Hartree-Fock-Bogoliubov (HFB) method in the coordinate space is preferred for deformed and weakly bound nuclei, as solvers based on basis expansions often have difficulty correctly describing continuum effects. A new HFB solver based on the canonical-basis HFB formalism in the three-dimensional coordinate space is developed in this dissertation. It is a well parallelized solver and has been carefully benchmarked against other established HFB solvers.