Electron, Spin and Momentum Densities and Chemical Reactivity

Electron, Spin and Momentum Densities and Chemical Reactivity PDF Author: Paul G. Mezey
Publisher: Springer Science & Business Media
ISBN: 030646943X
Category : Science
Languages : en
Pages : 328

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Book Description
The electron density of a non-degenerate ground state system determines essentially all physical properties of the system. This statement of the Hohenberg–Kohn theorem of Density Functional Theory plays an exceptionally important role among all the fundamental relations of Molecular Physics. In particular, the electron density distribution and the dynamic properties of this density determine both the local and global reactivities of molecules. High resolution experimental electron densities are increasingly becoming available for more and more molecules, including macromolecules such as proteins. Furthermore, many of the early difficulties with the determination of electron densities in the vicinity of light nuclei have been overcome. These electron densities provide detailed information that gives important insight into the fundamentals of molecular structure and a better understanding of chemical reactions. The results of electron density analysis are used in a variety of applied fields, such as pharmaceutical drug discovery and biotechnology. If the functional form of a molecular electron density is known, then various molecular properties affecting reactivity can be determined by quantum chemical computational techniques or alternative approximate methods.

Electron, Spin and Momentum Densities and Chemical Reactivity

Electron, Spin and Momentum Densities and Chemical Reactivity PDF Author: Paul G. Mezey
Publisher: Springer Science & Business Media
ISBN: 030646943X
Category : Science
Languages : en
Pages : 328

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Book Description
The electron density of a non-degenerate ground state system determines essentially all physical properties of the system. This statement of the Hohenberg–Kohn theorem of Density Functional Theory plays an exceptionally important role among all the fundamental relations of Molecular Physics. In particular, the electron density distribution and the dynamic properties of this density determine both the local and global reactivities of molecules. High resolution experimental electron densities are increasingly becoming available for more and more molecules, including macromolecules such as proteins. Furthermore, many of the early difficulties with the determination of electron densities in the vicinity of light nuclei have been overcome. These electron densities provide detailed information that gives important insight into the fundamentals of molecular structure and a better understanding of chemical reactions. The results of electron density analysis are used in a variety of applied fields, such as pharmaceutical drug discovery and biotechnology. If the functional form of a molecular electron density is known, then various molecular properties affecting reactivity can be determined by quantum chemical computational techniques or alternative approximate methods.

Chemical Reactivity Theory

Chemical Reactivity Theory PDF Author: Pratim Kumar Chattaraj
Publisher: CRC Press
ISBN: 1420065440
Category : Science
Languages : en
Pages : 612

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Book Description
In the 1970s, Density Functional Theory (DFT) was borrowed from physics and adapted to chemistry by a handful of visionaries. Now chemical DFT is a diverse and rapidly growing field, its progress fueled by numerous developing practical descriptors that make DFT as useful as it is vast. With 34 chapters written by 65 eminent scientists from 13 diffe

Positron Annihilation

Positron Annihilation PDF Author: Werner Triftshauser
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 756

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Book Description
When it comes to studying the structures and defects of materials, there is presently no technique that is superior to positron annihilation. The increasing demands for higher accuracy and reliability provide a constant stimulus to the field, and the present book relates the newest and most important scientific discoveries made in the field of positron annihilation.

New Trends in Quantum Systems in Chemistry and Physics

New Trends in Quantum Systems in Chemistry and Physics PDF Author: Jean Maruani
Publisher: Springer Science & Business Media
ISBN: 9781402004117
Category : Mathematics
Languages : en
Pages : 440

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Book Description
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.

A Matter of Density

A Matter of Density PDF Author: N. Sukumar
Publisher: John Wiley & Sons
ISBN: 1118431723
Category : Science
Languages : en
Pages : 263

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Book Description
The origins and significance of electron density in the chemical, biological, and materials sciences Electron density is one of the fundamental concepts underlying modern chemistry and one of the key determinants of molecular structure and stability. It is also the basic variable of density functional theory, which has made possible, in recent years, the application of the mathematical theory of quantum physics to chemical and biological systems. With an equal emphasis on computational and philosophical questions, A Matter of Density: Exploring the Electron Density Concept in the Chemical, Biological, and Materials Sciences addresses the foundations, analysis, and applications of this pivotal chemical concept. The first part of the book presents a coherent and logically connected treatment of the theoretical foundations of the electron density concept. Discussion includes the use of probabilities in statistical physics; the origins of quantum mechanics; the philosophical questions at the heart of quantum theory, like quantum entanglement; and methods for the experimental determination of electron density distributions. The remainder of the book deals with applications of the electron density concept in the chemical, biological, and materials sciences. Contributors offer insights on how a deep understanding of the origins of chemical reactivity can be gleaned from the concepts of density functional theory. Also discussed are the applications of electron density in molecular similarity analysis and electron density-derived molecular descriptors, such as electrostatic potentials and local ionization energies. This section concludes with some applications of modern density functional theory to surfaces and interfaces. An essential reference for students as well as quantum and computational chemists, physical chemists, and physicists, this book offers an unparalleled look at the development of the concept of electron density from its inception to its role in density functional theory, which led to the 1998 Nobel Prize in Chemistry.

Chemical Reactivity

Chemical Reactivity PDF Author: Savaş Kaya
Publisher: Elsevier
ISBN: 0323906125
Category : Science
Languages : en
Pages : 608

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Book Description
The growth of technology for chemical assessment has led to great developments in the investigation of chemical reactivity in recent years, but key information is often dispersed across many different research fields. Combining both original principles and the cutting-edge theories used in chemical reactivity analysis, Chemical Reactivity, Volume 1 present the latest developments in theoretical chemistry and its application for the assessment of chemical processes.Beginning with an exploration of different theories and principles relating to electronic structure and reactivity of confined electronic systems, the book goes on to highlight key information on such topics as Dyson orbitals, target-ion overlaps, reaction fragility, magnetizability principles and the Fuki function. Density Functional Theory is discussed in relation to numerous different principles and approaches, with further information on constrained methods and diabatic models, bonding evolution theory, orbital-based population analysis models and charge transfer models, and Quantum chemistry and QTAIM.Consolidating the knowledge of a global team of experts in the field, Chemical Reactivity, Volume 1: Theories and Principles is a useful resource for both students and researchers interested in gaining greater understanding of the principles and theories underpinning chemical reactivity analysis. - Provides readers with the key information needed to gain a good overview of contemporary chemical reactivity studies and a clear understanding of the theory behind state-of-the-art methods in the field - Highlights advances in the computational descriptions of reactivity, including reactivity in confined environments, conceptual density functional theory, and multi-reference quantum chemistry - Provides comprehensive coverage by consolidating the knowledge of many well-known researchers in the field from around the world

Bibliography of Agriculture with Subject Index

Bibliography of Agriculture with Subject Index PDF Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 830

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Book Description


High Energy Electron Diffraction and Microscopy

High Energy Electron Diffraction and Microscopy PDF Author: L. M. Peng
Publisher: Oxford University Press
ISBN: 0191004782
Category : Science
Languages : en
Pages : 558

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Book Description
This book provides a comprehensive introduction to high energy electron diffraction and elastic and inelastic scattering of high energy electrons, with particular emphasis on applications to modern electron microscopy. Starting from a survey of fundamental phenomena, the authors introduce the most important concepts underlying modern understanding of high energy electron diffraction. Dynamical diffraction in transmission (THEED) and reflection (RHEED) geometries is treated using a general matrix theory, where computer programs and worked examples are provided to illustrate the concepts and to familiarize the reader with practical applications. Diffuse and inelastic scattering and coherence effects are treated comprehensively both as a perturbation of elastic scattering and within the general multiple scattering quantum mechanical framework of the density matrix method. Among the highlights are the treatment of resonance diffraction of electrons, HOLZ diffraction, the formation of Kikuchi bands and lines and ring patterns, and application of diffraction to monitoring of growing surfaces. Useful practical data are summarised in tables including those of electron scattering factors for all the neutral atoms and many ions, and the temperature dependent Debye-Waller factors given for over 100 elemental crystals and compounds.

Electron Paramagnetic Resonance

Electron Paramagnetic Resonance PDF Author: John A. Weil
Publisher: John Wiley & Sons
ISBN: 0470084979
Category : Science
Languages : en
Pages : 690

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Book Description
This book provides an introduction to the underlying theory, fundamentals, and applications of EPR spectroscopy, as well as new developments in the area. Knowledge of the topics presented will allow the reader to interpret of a wide range of EPR spectra, as well as help them to apply EPR techniques to problem solving in a wide range of areas: organic, inorganic, biological, and analytical chemistry; chemical physics, geophysics, and minerology. Includes updated information on high frequency and multi-frequency EPR, pulsed microwave techniques and spectra analysis, dynamic effects, relaxation phenomena, computer-based spectra simulation, biomedical aspects of EPR, and more Equips readers with sufficient knowledge of EPR techniques to go on in their specialized area of interest Provides problem sets and concise bibliographies at the end of each chapter, plus several tutorial appendices on topics like mathematical operations, quantum mechanics of angular momentum, experimental considerations.

Quantum Crystallography

Quantum Crystallography PDF Author: Chérif Matta
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110566672
Category : Science
Languages : en
Pages : 216

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Book Description
Quantum Crystallography is a novel scientific discipline combining quantum chemistry methods and crystal structure determination. The current book describes quantum-mechanical approaches to obtain crystallographic data of enhanced value and explains how they correlate with real diffraction and scattering experiments. In particular, the book covers DFT, Clinton equations, KEM and QTAIM methods and their applications in crystallographic studies.