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Electron Correlations and Materials Properties 2

by A. Gonis Nicholis Kioussis Mikael Ciftan

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.

Electron Correlations in Molecules and Solids (Springer Series in Solid-State Sciences #100)

by Peter Fulde

Quantum chemistry and solid-state theory are two important related fields of research that have grown up with almost no cross communication. This book bridges the gap between the two. In the first half, new concepts for treating weak and strong correlations are developed, and standard quantum-chemical methods, as well as density functional, Green's function, functional integral, and Monte Carlo methods are discussed. The second half discusses applications of the theory to molecules, semiconductors, homogeneous metallic systems, transition metals, and strongly correlated systems such as heavy-fermion systems and the new high-Tc superconducting materials.

Electron Correlations in Molecules and Solids (Springer Series in Solid-State Sciences #100)

by Peter Fulde

This volume bridges the gap between quantum chemistry and solid-state theory. The text develops new concepts for treating many-body and correlation effects, and deals with applications of the theory to molecules, semiconductors, transition metals, heavy-fermion systems, and the new high-Tc superconducting materials.

Electron Correlations in Molecules and Solids (Springer Series in Solid-State Sciences #100)

by Peter Fulde

Dieser Titel verbindet die Festkörpertheorie mit der Quantenchemie. Neue Konzepte der Vielteilchen-Verarbeitung und Korrelations-Effekte, normale quantenchemische Verfahren mit Projektionstechniken, Greensche Funktionen und Monte-Carlo-Methoden werden erarbeitet. Anwendungsbereiche der Molekültheorie, von Halbleitern, supraleitender high-Tc-Materialien, etc., werden vorgestellt.

Electron Correlations in Solids, Molecules, and Atoms (Nato Science Series B: #81)

by Jozef T. Devreese Fons Brosens

From July 20 till 31, 1981, the Advanced Study Institute on "Electron Correlations in Solids, Molecules and Atoms", sponsored by NATO, was held at the University of Antwerpen (U.I.A.), in the Conference Center Corsendonk. In the last few years, the problem of many-electron correlations has gained renewed attention, due to recent experimental and theoretic­ al developments. From the theoretical point of view, more sophisticated treatments of the homogeneous electron gas model evolved, including dynamical aspects of the electron correlation in the dielectric response. Furthermore, the homogeneous electron gas, which served as a model for simple metals, was extended to include spin- and charge-density waves and phasons. The concept of elementary excitations too was introduced not only in perfectly ordered metallic crystals, but also in magnetic alloys, in liquid metals and alloys, in semiconductors, and even in molecules and atoms. Fairly accurate quantitative calculations of these effects recently became possible, ranging from plasmon frequencies in atoms, over dielectric response of semiconduc­ tors and resistivity in magnetic alloys to electron-hole liquids and their phase separation. The recent technological evolution allowed for more accurate measurements in previously unaccessible domains, e.g. X-ray scatter­ ing and fast electron energy loss at large wavevector. Moreover, these new developments opened new perspectives in physics, accompany­ ing or even introducing the new concepts which also evolved in the theory.

Electron Crystallography (NATO Science Series E: #347)

by D. Dorset Sven Hovmöller Xiaodong Xiaodong Zou

The re-emergent field of quantitative electron crystallography is described by some of its most eminent practitioners. They describe the theoretical framework for electron scattering, specimen preparation, experimental techniques for optimum data collection, the methodology of structure analysis and refinement, and a range of applications to inorganic materials (including minerals), linear polymers, small organic molecules (including those used in nonlinear optical devices), incommensurately modulated structures (including superconductors), alloys, and integral membrane proteins. The connection between electron crystallography and X-ray crystallography is clearly defined, especially in the utilisation of the latest methods for direct determination of crystallographic phases, as well as the unique role of image analysis of high-resolution electron micrographs for phase determination. Even the aspect of multiple beam dynamic diffraction (once dreaded because it was thought to preclude ab initio analysis) is considered as a beneficial aid for symmetry determination as well as the elucidation of crystallographic phases, and as a criterion for monitoring the progress of structure refinement. Whereas other texts have hitherto preferentially dealt with the analysis of electron diffraction and image data from thin organic materials, this work discusses - with considerable optimism - the prospects of looking at `harder' materials, composed of heavier atoms. Audience: Could be used with profit as a graduate-level course on electron crystallography. Researchers in the area will find a statement of current progress in the field.

Electron Crystallography: Novel Approaches for Structure Determination of Nanosized Materials (NATO Science Series II: Mathematics, Physics and Chemistry #211)

by Thomas E. Weirich János L. Lábár Xiaodong Zou

During the last decade we have been witness to several exciting achievements in electron crystallography. This includes structural and charge density studies on organic molecules complicated inorganic and metallic materials in the amorphous, nano-, meso- and quasi-crystalline state and also development of new software, tailor-made for the special needs of electron crystallography. Moreover, these developments have been accompanied by a now available new generation of computer controlled electron microscopes equipped with high-coherent field-emission sources, cryo-specimen holders, ultra-fast CCD cameras, imaging plates, energy filters and even correctors for electron optical distortions. Thus, a fast and semi-automatic data acquisition from small sample areas, similar to what we today know from imaging plates diffraction systems in X-ray crystallography, can be envisioned for the very near future. This progress clearly shows that the contribution of electron crystallography is quite unique, as it enables to reveal the intimate structure of samples with high accuracy but on much smaller samples than have ever been investigated by X-ray diffraction. As a tribute to these tremendous recent achievements, this NATO Advanced Study Institute was devoted to the novel approaches of electron crystallography for structure determination of nanosized materials.

Electron Crystallography of Organic Molecules (Nato Science Series C: #328)

by J. R. Fryer D. Dorset

Maximum Entropy (ME) techniques have found widespread applicability in the reconstruction of incomplete or noisy data. These techniques have been applied in many areas of data analysis including imaging, spectroscopy, and scattering [Gull and Skilling, 1984]. The techniques have proven particularly useful in astronomy [Narayan and Nityanada, 1984]. In many of these applications the goal of the reconstruction is the detection of point objects against a noisy background. In this work we investigate the applicability of ME techniques to data sets which have strong components which are periodic in space or time. The specific interest in our laboratory is High Resolution Electron Micrographs of beam sensitive materials. However, ME techniques are of general interest for all types of data. These data mayor may not have a spatial or temporal character. Figure 1 shows an HREM image of the rigid-rod polymer poly(paraphenylene benzobisoxazole) (PBZO). The 0.55 nm spacings in the image correspond to the lateral close-packing between the extended polymer molecules. Near the center of this crystallite there is evidence for an edge dislocation. In HREM images both the frequency and position of the infonnation is important for a proper interpretation. Therefore, it is necessary to consider how image processing affects the fidelity of this information in both real and Fourier space.

Electron Crystallography of Soluble and Membrane Proteins: Methods and Protocols (Methods in Molecular Biology #955)

by Ingeborg Schmidt-Krey and Yifan Cheng

The basic principle of electron crystallography is to calculate a 3D density map by combining the amplitudes obtained from electron diffraction patterns with the experimental phases calculated from images of two-dimensional crystals of membrane or soluble proteins. This technology is very well developed and has produced a number of atomic models of membrane proteins in a lipid environment. Focused on comprehensive experimental protocols, Electron Crystallography of Soluble and Membrane Proteins: Methods and Protocols covers the entire range of techniques used in electron crystallography, including protein sample preparation, 2D crystallization, and screening in negative stain over electron cryo-microscopy (cryo-EM) and data processing, as well as modeling of conformational changes. Additional chapters provide perspective on past, present, and future challenges as well as complementary methods. Written for the popular Methods in Molecular Biology™ series, the work contains the kind of detailed descriptions and implementation advice necessary to ensure successful results. Comprehensive and cutting-edge, Electron Crystallography of Soluble and Membrane Proteins: Methods and Protocols serves laboratories new to the methods as well as state-of-the-art facilities pursuing this exciting area of protein science.

Electron Cyclotron Heating of Plasmas

by Gareth Guest

Authored by a highly regarded plasma scientist, this book fills the gap for a topical reference and source with a professional audience in mind. While the use of this critical method at the international fusion reactor, ITER, is covered in detail, the monograph also includes planetary magnetospheres and plasma sources for commercial applications. With exercises and solutions for additional use as course reading.

Electron Cyclotron Resonance Ion Sources and ECR Plasmas

by R Geller

Acknowledged as the "founding father" of and world renowned expert on electron cyclotron resonance sources Richard Geller has produced a unique book devoted to the physics and technicalities of electron cyclotron resonance sources. Electron Cyclotron Resonance Ion Sources and ECR Plasmas provides a primer on electron cyclotron phenomena in ion sour

Electron Cyclotron Resonance Ion Sources and ECR Plasmas

by R Geller

Acknowledged as the "founding father" of and world renowned expert on electron cyclotron resonance sources Richard Geller has produced a unique book devoted to the physics and technicalities of electron cyclotron resonance sources. Electron Cyclotron Resonance Ion Sources and ECR Plasmas provides a primer on electron cyclotron phenomena in ion sour

Electron Deficient Compounds (Studies in Modern Chemistry)

by K. Wade

This book is about compounds such as the boron hydrides and associated metal hydrides and alkyls which acquired the label 'electron deficient' when they were thought to contain too few valence electrons to hold together. Though they are now recognized as containing the numbers of bonding electrons appropriate for their structures, the term 'electron deficient' is still commonly applied to many substances that contain too few valence electrons to provide a pair for every pair of atoms close enough to be regarded as covalently bonded. The study of such substances has contributed much to chemistry. Techniques for the vacuum manipulation of volatile substances were devised specifically for their study; developments in valence theory resulted from considerations of their bonding; and the reactivity of several (for example, diborane and complex metal hydrides, lithium and aluminium alkyls) has made them valuable reagents. The purpose of this book is to provide an introduction to the chemistry of these fascinating compounds. The experimental and spectroscopic methods by which they can be studied are outlined, the various types of structure they adopt are described and profusely illustrated, and the relative merits of extended valence bond and simple molecular orbital treatments of their bonding are discussed, with as liberal use of diagrams and as limited recourse to the Greek alphabet as possible. A recurring theme is the importance attached to considerations of molecular sym­ metry. Their reactions are treated in sufficient detail to show whether these reflect any deficiency of electrons.

Electron Density: Concepts, Computation and DFT Applications

by Pratim Kumar Chattaraj Debdutta Chakraborty

Discover theoretical, methodological, and applied perspectives on electron density studies and density functional theory Electron density or the single particle density is a 3D function even for a many-electron system. Electron density contains all information regarding the ground state and also about some excited states of an atom or a molecule. All the properties can be written as functionals of electron density, and the energy attains its minimum value for the true density. It has been used as the basis for a quantum chemical computational method called Density Functional Theory, or DFT, which can be used to determine various properties of molecules. DFT brings out a drastic reduction in computational cost due to its reduced dimensionality. Thus, DFT is considered to be the workhorse for modern computational chemistry, physics as well as materials science. Electron Density: Concepts, Computation and DFT Applications offers an introduction to the foundations and applications of electron density studies and analysis. Beginning with an overview of major methodological and conceptual issues in electron density, it analyzes DFT and its major successful applications. The result is a state-of-the-art reference for a vital tool in a range of experimental sciences. Readers will also find: A balance of fundamentals and applications to facilitate use by both theoretical and computational scientists Detailed discussion of topics including the Levy-Perdew-Sahni equation, the Kohn Sham Inversion problem, and more Analysis of DFT applications including the determination of structural, magnetic, and electronic properties Electron Density: Concepts, Computation and DFT Applications is ideal for academic researchers in quantum, theoretical, and computational chemistry and physics.

Electron Density: Concepts, Computation and DFT Applications

by Pratim Kumar Chattaraj Debdutta Chakraborty

Discover theoretical, methodological, and applied perspectives on electron density studies and density functional theory Electron density or the single particle density is a 3D function even for a many-electron system. Electron density contains all information regarding the ground state and also about some excited states of an atom or a molecule. All the properties can be written as functionals of electron density, and the energy attains its minimum value for the true density. It has been used as the basis for a quantum chemical computational method called Density Functional Theory, or DFT, which can be used to determine various properties of molecules. DFT brings out a drastic reduction in computational cost due to its reduced dimensionality. Thus, DFT is considered to be the workhorse for modern computational chemistry, physics as well as materials science. Electron Density: Concepts, Computation and DFT Applications offers an introduction to the foundations and applications of electron density studies and analysis. Beginning with an overview of major methodological and conceptual issues in electron density, it analyzes DFT and its major successful applications. The result is a state-of-the-art reference for a vital tool in a range of experimental sciences. Readers will also find: A balance of fundamentals and applications to facilitate use by both theoretical and computational scientists Detailed discussion of topics including the Levy-Perdew-Sahni equation, the Kohn Sham Inversion problem, and more Analysis of DFT applications including the determination of structural, magnetic, and electronic properties Electron Density: Concepts, Computation and DFT Applications is ideal for academic researchers in quantum, theoretical, and computational chemistry and physics.

Electron Density and Chemical Bonding I: Experimental Charge Density Studies (Structure and Bonding #146)

by Dietmar Stalke

D. Stalke, U. Flierler: More than Just Distances from Electron Density Studies.-A.O. Madsen: Modeling and Analysis of Hydrogen Atoms.-B.B. Iversen/J. Overgaard: Charge Density Methods in Hydrogen Bond Studies.-U. Flierler, D. Stalke: Some Main Group Chemical Perceptions in the Light of Experimental Charge Density Investigations.-D. Leusser: Electronic Structure and Chemical Properties of Lithium Organics Seen Through the Glasses of Charge Density.-L. J. Farrugia, P. Macchi: Bond Orders in Metal–Metal Interactions Through Electron Density Analysis.-W. Scherer, V. Herz, Ch. Hauf: On the Nature of β-Agostic Interactions: A Comparison Between the Molecular Orbital and Charge Density Picture.

Electron Density and Chemical Bonding II: Theoretical Charge Density Studies (Structure and Bonding #147)

by Dietmar Stalke

T. Koritsanszky, A. Volkov, M. Chodkiewicz: New Directions in Pseudoatom-Based X-Ray Charge Density Analysis.-B. Dittrich, D. Jayatilaka: Reliable Measurements of Dipole Moments from Single-Crystal Diffraction Data and Assessment of an In-Crystal Enhancement.-B. Engels, Th. C. Schmidt, C. Gatti, T. Schirmeister, R.F. Fink: Challenging Problems in Charge Density Determination: Polar Bonds and Influence of the Environment.-S. Fux, M. Reiher: Electron Density in Quantum Theory.-K. Meindl, J.Henn: Residual Density Analysis.-C. Gatti: The Source Function Descriptor as a Tool to Extract Chemical Information from Theoretical and Experimental Electron Densities.

Electron Diffraction and High-Resolution Electron Microscopy of Mineral Structures

by Victor A. Drits

The decision of Springer-Verlag to publish this book in English came as a pleasant surprise. The fact is that I started writing the first version of the book back in 1978. I wished to attract attention to potentialities inherent in selected-area electron diffraction (SAED) which, for various reasons, were not being put to use. By that time, I had at my disposal certain structural data on natural and synthetic minerals obtained using SAED and high-resolution electron microscopy (HREM), and this stimulated my writing this book. There were several aspects concerning these data that I wished to emphasize. First, it was mostly new and understudied minerals that possess the peculiar structural features studied by SAED and HREM. This could interest mineralogists, crystallo­ chemists, and crystallographers. Second, the results obtained indi­ cated that, under certain conditions, SAED could be an effective, and sometimes the only possible, method for structure analysis of minerals. This inference was of primary importance, since fine dispersion and poor crystallinity of numerous natural and synthe­ tic minerals makes their structure study by conventional diffrac­ tion methods hardly possible. Third, it was demonstrated that in many cases X-ray powder diffraction analysis of dispersed miner­ als ought to be combined with SAED and local energy dispersion analysis. This was important, since researchers in structural min­ eralogy quite often ignored, and still ignore even the simplest in­ formation which is readily available from geometrical analysis of SAED patterns obtained from microcrystals.

Electron Diffraction in the Transmission Electron Microscope

by P.E. Champness

This book is a practical guide to electron diffraction in the transmission electron microscope (TEM). Case studies and examples are used to provide an invaluable introduction to the subject for those new to the technique. The book explains the basic methods used to obtain diffraction patterns with the TEM. The numerous illustrations aid the understanding of the conclusions reached.

Electron Diffraction in the Transmission Electron Microscope

by P.E. Champness

This book is a practical guide to electron diffraction in the transmission electron microscope (TEM). Case studies and examples are used to provide an invaluable introduction to the subject for those new to the technique. The book explains the basic methods used to obtain diffraction patterns with the TEM. The numerous illustrations aid the understanding of the conclusions reached.

Electron Distributions and the Chemical Bond

by Philip Coppens Michael B. Hall

This book represents the proceedings of a symposium held at the Spring 1981 ACS meeting in Atlanta. The symposium brought together Theoretical Chemists, Solid State Physicists, Experimen­ tal Chemists and Crystallographers. One of its major aims was to increase interaction between these diverse groups which often use very different languages to describe similar concepts. The devel­ opment of a common language, or at least the acquisition of a multilingual capability, is a necessity if the field is to prosper. Much depends in this field on the interplay between theory and experiment. Accordingly this volume begins with two introduc­ tory chapters, one theoretical and the other experimental, which contain much of the background material needed for a through under­ standing of the field. The remaining sections describe a wide variety of applications and illustrate, we believe, the central role of charge densities in the understanding of chemical bonding. We are most indebted to the Divisions of Inorganic and Phy­ sical Chemistry of the American Chemical Society, which provided the stimulus for the symposium and gave generous financial support. We also gratefully acknowledge financial support from the Special Educational Opportunities Program of the Petroleum Research Fund administered by the American Chemical Society, which made exten­ sive participation by speakers from abroad possible.

Electron-Electron Correlation Effects in Low-Dimensional Conductors and Superconductors (Research Reports in Physics)

by Alexandr A. Ovchinnikov Ivan I. Ukrainskii

Advances in the physics and chemistry of low-dimensional systems have been really magnificent in the last few decades. Hundreds of quasi-one-dimensional and quasi-two-dimensional systems have been synthesized and studied. The most popular representatives of quasi-one-dimensional materials are polyacethylenes CH [1] and conducting donor-acceptor molecular crystals TIF­ z TCNQ. Examples of quasi-two-dimensional systems are high temperature su­ perconductors (HTSC) based on copper oxides LA2CU04, YBa2Cu306+y and organic superconductors based on BEDT -TIP molecules. The properties of such one- and two-dimensional materials are not yet fully understood. On the one hand, the equations of motion of one-dimensional sys­ tems are rather simple, which facilitates rigorous solutions of model problems. On the other hand, manifestations of various interactions in one-dimensional systems are rather peculiar. This refers, in particular, to electron--electron and electron-phonon interactions. Even within the limit of a weak coupling con­ stant electron--electron correlations produce an energy gap in the spectrum of one-dimensional metals implying a Mott transition from metal to semiconductor state. In all these cases perturbation theory is inapplicable. Which is one of the main difficulties on the way towards a comprehensive theory of quasi-one-dimensional systems. - This meeting held at the Institute for Theoretical Physics in Kiev May 15-18 1990 was devoted to related problems. The papers selected for this volume are grouped into three sections.

Electron-Emission Gas Discharges I / Elektronen-Emission Gasentladungen I (Handbuch der Physik Encyclopedia of Physics #4 / 21)

by S. Flügge

v. Formation of negative ions by processes other than attachment in the gaseous phase at low X/po 17. Introduction. As early as 1912, J. J. THOMSON [32J in his first mass spectro­ graph observed negative ions of 0-, Cl-, H- and what he believed to be N-. He at first ascribed these to possible dissociation of polar gaseous compounds by electron impact but control studies using ionization at low energies in glow discharges indicated that this was not the origin. O. W. RICHARDSON [33J in his book on emission of electricity from hot bodies reported negative ions to come from hot salts. From there on many experimental studies over the years indicated that negative ions could be formed by various processes. By the middle nineteen hundred and thirties the data fairly clearly identified several processes as being active and MASSEY and SMITH [34J developed the theory underlying some of them. More data are summarized in MASSEY'S excellent little monograph on Negative Ions and in )L\SSEY and BURHOP'S recent book [35]. Since that period, stimulated by various investigations and certain industrial problems, very careful studies of the appearance of such ions by mass spectrograph have been carried out in the laboratory of K. G. EMELEUS in Belfast by SLOANE and his co-workers [3J that haw clarified the questions and indicated what ions have been observed and something of the processes at work.

Electron Emission in Heavy Ion-Atom Collisions (Springer Series on Atomic, Optical, and Plasma Physics #20)

by Nikolaus Stolterfoht Robert D. DuBois Roberto D. Rivarola

Electron EM reviews the theoretical and experimental work of the last 30 years on continuous electron emission in energetic ion-atom collisions. High incident energies for which the projectile is faster than the mean orbital velocity of the active electron are considered. Emphasis is placed on the interpretation of ionization mechanisms. They are interpreted in terms of Coulomb centers associated with the projectile and target nuclear fields which strongly interact with the outgoing electron. General properties of the two-center electron emission are analyzed. Particular attention is given to screening effects. A brief overview of multiple ionization processes is also presented. The survey concludes with a complete compilation of experimental studies of ionization cross sections.

Electron Emission Spectroscopy: Proceedings of the NATO Summer Institute Held at the University of Gent, August 28–September 7, 1972

by W. Dekeyser L. Fiermans G. Vanderkelen J. Vennik

Electron emission spectroscopy became recently a major tool for the study of molecules and solids. These volumes contain a rather complete review of the state of the art in this field. Both the physical and chemical aspects are covered extensively by well­ known specialists. Different modes of excitation are used in electron emission spec­ troscopy. The electron-solid scattering is covered in detail by C. B. Duke, from a theoretical point of view. Elastic and inelastic low energy electron diffraction are extensively discussed in relation to the geometrical, electronic and vibronic structure of solid surfaces. Auger electron emission spectroscopy (AES) is covered by J. C. Tracy. The tech­ nique is discussed from the point of view of surface research. This part also contains a complete literature list concerning the application of AES up to the middle of 1972. Electron emission produced by X-ray impact, is covered by C. S. Fadley, D. T. Clark, R. P. Gupta and S. K. Sen. The contribution by C. S. Fadley, entitled Theoretical Aspects of X-Ray Photo­ electron Spectroscopy', is an up to date discussion of core electron binding energies, valence electron binding energies, multiplet splittings and multi-electron processes. R. P. Gupta and S. K. Sen's contribution provides an introduction to crystal field theory and its application to electron energy level determination. D. T. Clark deals with the more chemical aspects of X-ray photoelectron spectroscopy, i.e. the study of chemical shifts and the relation to the bonding characteristics in molecules.

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