Quantal Density Functional Theory
Quantal Density Functional Theory

Author: Viraht Sahni

Publisher: Springer Science & Business Media

Published: 2013-03-14

Total Pages: 265

ISBN-13: 3662096242

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Density functional theory is an important and widely used tool in many-body physics that has found applications in atomic, molecular, solid-state and nuclear physics. It is used principally to determine the electronic structure of these complex systems. Sahni has developed a new approach, termed quantal density functional theory, which simplifies the process of solving the computational problem and at the same time, gives insight into the underlying quantum mechanics. Further, the book 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

Quantal Density Functional Theory II
Quantal Density Functional Theory II

Author: Viraht Sahni

Publisher: Springer Science & Business Media

Published: 2009-10-16

Total Pages: 426

ISBN-13: 3540922296

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In my original proposal to Springer for a book on Quantal Density Functional Theory, I had envisaged one that was as complete in its presentation as possible, describing the basic theory as well as the approximation methods and a host of applications. However,after workingon the bookforabout ?ve years, I realizedthat the goal was too ambitious, and that I would be writing for another ?ve years for it to be achieved. Fortunately,there was a natural breakin the material, and I proposed to my editor, Dr. Claus Ascheron, that we split the book into two components: the ?rst on the basic theoretical framework, and the second on approximation methods and applications. Dr. Ascheron consented, and I am thankful to him for agreeing to do so. Hence, we published Quantal Density Functional Theory in 2004, and are now publishing Quantal Density Functional Theory II: Approximation Methods and Applications. One signi?cant advantage of this, as it turns out, is that I have been able to incorporate in each volume the most recent understandings available. This volume, like the earlier one, is aimed at advanced undergraduates in physics and chemistry, graduate students and researchers in the ?eld. It is written in the same pedagogical style with details of all proofs and numerous ?gures provided to explain the physics. The book is independent of the ?rst volume and stands on its own. However, proofs given in the ?rst volume are not repeated here.

Quantal Density Functional Theory
Quantal Density Functional Theory

Author: Viraht Sahni

Publisher: Springer

Published: 2016-08-12

Total Pages: 417

ISBN-13: 3662498421

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This book is on quantal density functional theory (QDFT) which is a time-dependent local effective potential theory of the electronic structure of matter. The time-independent QDFT constitutes a special case. The 2nd edition describes the further development of the theory, and extends it to include the presence of an external magnetostatic field. The theory is based on the ‘quantal Newtonian’ second and first laws for the individual electron. These laws are in terms of ‘classical’ fields that pervade all space, and their quantal sources. The fields are separately representative of the electron correlations that must be accounted for in local potential theory. Recent developments show that irrespective of the type of external field the electrons are subject to, the only correlations beyond those due to the Pauli exclusion principle and Coulomb repulsion that need be considered are solely of the correlation-kinetic effects. Foundational to QDFT, the book describes Schrödinger theory from the new perspective of the single electron in terms of the ‘quantal Newtonian’ laws. Hohenberg-Kohn density functional theory (DFT), new understandings of the theory and its extension to the presence of an external uniform magnetostatic field are described. The physical interpretation via QDFT, in terms of electron correlations, of Kohn-Sham DFT, approximations to it and Slater theory are provided.

Quantal Density Functional Theory
Quantal Density Functional Theory

Author: Viraht Sahni

Publisher: Springer Science & Business Media

Published: 2004-01-13

Total Pages: 284

ISBN-13: 9783540408840

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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.

Schrödinger Theory of Electrons: Complementary Perspectives
Schrödinger Theory of Electrons: Complementary Perspectives

Author: Viraht Sahni

Publisher: Springer Nature

Published: 2022-07-08

Total Pages: 415

ISBN-13: 303097409X

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This book presents a complementary perspective to Schrödinger theory of electrons in an electromagnetic field, one that does not appear in any text on quantum mechanics. The perspective, derived from Schrödinger theory, is that of the individual electron in the sea of electrons via its temporal and stationary-state equations of motion – the ‘Quantal Newtonian’ Second and First Laws. The Laws are in terms of ‘classical’ fields experienced by each electron, the sources of the fields being quantum-mechanical expectation values of Hermitian operators taken with respect to the wave function. Each electron experiences the external field, and internal fields representative of properties of the system, and a field descriptive of its response. The energies are obtained in terms of the fields. The ‘Quantal Newtonian’ Laws lead to physical insights, and new properties of the electronic system are revealed. New mathematical understandings of Schrödinger theory emerge which show the equation to be intrinsically self-consistent. Another complimentary perspective to Schrödinger theory is its manifestation as a local effective potential theory described via Quantal Density Functional theory. This description too is in terms of ‘classical’ fields and quantal sources. The theory provides a rigorous physical explanation of the mapping from the interacting system to the local potential theory equivalent. The complementary perspective to stationary ground state Schrödinger theory founded in the theorems of Hohenberg and Kohn, their extension to the presence of a magnetic field and to the temporal domain – Modern Density Functional Theory -- is also described. The new perspectives are elucidated by application to analytically solvable interacting systems. These solutions and other relevant wave function properties are derived.

A Trajectory Description of Quantum Processes. II. Applications
A Trajectory Description of Quantum Processes. II. Applications

Author: Ángel S. Sanz

Publisher: Springer

Published: 2013-09-13

Total Pages: 345

ISBN-13: 3642179746

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Trajectory-based formalisms are an intuitively appealing way of describing quantum processes because they allow the use of "classical" concepts. Beginning as an introductory level suitable for students, this two-volume monograph presents (1) the fundamentals and (2) the applications of the trajectory description of basic quantum processes. This second volume is focussed on simple and basic applications of quantum processes such as interference and diffraction of wave packets, tunneling, diffusion and bound-state and scattering problems. The corresponding analysis is carried out within the Bohmian framework. By stressing its interpretational aspects, the book leads the reader to an alternative and complementary way to better understand the underlying quantum dynamics.

Electron Correlations and Materials Properties 2
Electron Correlations and Materials Properties 2

Author: A. Gonis

Publisher: Springer Science & Business Media

Published: 2013-03-09

Total Pages: 413

ISBN-13: 1475737602

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This is the second in a series of "International Workshops on Electron Correlations and Materials Properties. " The aim of this series of workshops is to provide a periodic (triennial) and in-depth assessment of advances in the study and understanding of the effects that electron-electron interactions in solids have on the determination of measurable properties of materials. The workshop is structured to include exposure to experimental work, to phenomenology, and to ab initio theory. Since correlation effects are pervasive the workshop aims to concentrate on the identification of promising developing methodology, experimental and theoretical, addressing the most critical frontier issues of electron correlations on the properties of materials. This series of workshops is distinguished from other topical meetings and conferences in that it strongly promotes an interdisciplinary approach to the study of correlations, involving the fields of quantum chemistry, physics, and materials science. The First Workshop was held June 28-July 3, 1998, and a proceedings of the workshop was published by KluwerlPlenum. The Second Workshop was held June 24- 29,2001, and this volume contains the proceedings of that scientific meeting. Through the publications of proceedings, the workshop attempts to disseminate the information gathered during the discussions held at the Workshop to the wider scientific community, and to establish a record of advances in the field.

Corrosion Inhibitors
Corrosion Inhibitors

Author: Ambrish Singh

Publisher: BoD – Books on Demand

Published: 2019-08-07

Total Pages: 206

ISBN-13: 1789847141

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This book aims to provide readers with the latest and relevant trends in corrosion. Use of inhibitors is one of the most common, cheap, and globally followed methods for the protection of metals from aggressive solutions. The information contained in this book covers different corrosion inhibitors for different corrosive environments with sufficient experimental data, surface studies, and theoretical studies. These studies altogether will give readers a good view of the basic and advanced knowledge of corrosion inhibitors and will be of interest to students, academicians, and industrialists.

Density Functional Theory
Density Functional Theory

Author: David S. Sholl

Publisher: John Wiley & Sons

Published: 2011-09-20

Total Pages: 252

ISBN-13: 1118211049

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Demonstrates how anyone in math, science, and engineering can master DFT calculations Density functional theory (DFT) is one of the most frequently used computational tools for studying and predicting the properties of isolated molecules, bulk solids, and material interfaces, including surfaces. Although the theoretical underpinnings of DFT are quite complicated, this book demonstrates that the basic concepts underlying the calculations are simple enough to be understood by anyone with a background in chemistry, physics, engineering, or mathematics. The authors show how the widespread availability of powerful DFT codes makes it possible for students and researchers to apply this important computational technique to a broad range of fundamental and applied problems. Density Functional Theory: A Practical Introduction offers a concise, easy-to-follow introduction to the key concepts and practical applications of DFT, focusing on plane-wave DFT. The authors have many years of experience introducing DFT to students from a variety of backgrounds. The book therefore offers several features that have proven to be helpful in enabling students to master the subject, including: Problem sets in each chapter that give readers the opportunity to test their knowledge by performing their own calculations Worked examples that demonstrate how DFT calculations are used to solve real-world problems Further readings listed in each chapter enabling readers to investigate specific topics in greater depth This text is written at a level suitable for individuals from a variety of scientific, mathematical, and engineering backgrounds. No previous experience working with DFT calculations is needed.