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Books > Science & Mathematics > Chemistry > Physical chemistry > Quantum & theoretical chemistry
The concepts of the Jahn-Teller effect and vibronic coupling are
being applied to more and more systems in both chemistry and
physics. Aspects of structural chemistry such as the distortion of
the nuclear framework to a lower-symmetry conformation have
received an increasing attention, as well as the dynamics on the
coupled potential energy surfaces.
The Jahn-Teller intersections are now recognized as prototype cases
of conical intersections where the nuclear motion is known to be
inherently nonadiabatic in nature and interchanges freely between
the different potential energy surfaces. In the condensed phase
especially, the significance of the Jahn-Teller effect has been
increasingly appreciated, following the discovery of
superconductivity in the fullerides and of very large ("colossal")
magnetoresistance in the manganite perovskites. Indeed, these
materials are particularly challenging since the Jahn-Teller
interaction competes with electronic correlation effects.
"Vibronic Interactions and the Jahn-Teller Effect: Theory and
Applications" provides an in-depth discussion of the Jahn-Teller
effect and vibronic interactions as reflected by the contributions
presented at the XX International Conference on the Jahn-Teller
effect, Fribourg, Switzerland, 2010. The following topics have been
treated in a clear and concise way:
Complex topologies of Jahn-Teller effect and conical
intersections
Multi-state vibronic interactions on strongly coupled potential
energy surfaces
Interplay of vibronic and spin-orbit coupling
Strain in Jahn-Teller systems and cooperative Jahn-Teller
effect
Orbital ordering and its relation to ferromagnetism,
ferroelectricity and molecular magnets
The Jahn-Teller effect in icosahedral systems
The Jahn-Teller effect and high temperature
superconductivity
This book is of interest to a wide audience including academic and
industrial theoretical and experimental physicists, chemists,
spectroscopists, and crystallographers.
"
A broad range of state-of-the-art methods to determine properties
of clusters are presented. The experimental setup and underlying
physical concepts of these experiments are described.
Furthermore, existing theoretical models to explain the
experimental observations are introduced and the possibility to
deduce structural information from measurements of dielectric
properties is discussed.
Additional case studies are presented in the book to emphasize the
possibilities but also drawbacks of the methods.
In this volume, Prof. Zhang reviews the systematic theoretical
studies in his group on the growth mechanisms and properties of
silicon quantum dots, nanotubes and nanowires, including:
mechanisms of oxide-assisted growth of silicon nanowires, energetic
stability of pristine silicon nanowires and nanotubes, thermal
stability of hydrogen terminated silicon nanostructures,
size-dependent oxidation of hydrogen terminated silicon
nanostructures, excited-state relaxation of hydrogen terminated
silicon nanodots, and direct-indirect energy band transitions of
silicon nanowires and sheets by surface engineering and straining.
He also discusses the potential applications of these findings.
This book will mainly benefit those members of the scientific and
research community working in nanoscience, surface science,
nanomaterials and related fields.
"Imagination and shrewd guesswork are powerful instruments for
acquiring scientific knowledge . . . " 1. H. van't Hoff The last
decades have witnessed a rapid growth of quantum chemistry and a
tremendous increase in the number of very accurate ab initio
calculations of the electronic structure of molecules yielding
results of admirable accuracy. This dramatic progress has opened a
new stage in the quantum mechanical description of matter at the
molecular level. In the first place, highly accurate results
provide severe tests of the quantum mecha nics. Secondly, modern
quantitative computational ab initio methods can be synergetically
combined with various experimen tal techniques thus enabling
precise numerical characterization of molecular properties better
than ever anticipated earlier. However, the role of theory is not
exhausted in disclosing the fundamental laws of Nature and
production of ever increasing sets of data of high accuracy. It has
to provide additionally a means of systematization, recognition of
regularities, and ratio nalization of the myriads of established
facts avoiding in this way complete chaos. Additional problems are
represented by molecular wavefunctions provided by the modern
high-level computational quantum chemistry methods. They involve,
in principle, all the information on molecular system, but they are
so immensely complex that can not be immediately understood in
simple and physically meaningful terms. Both of these aspects,
categorization and interpretation, call for conceptual models which
should be preferably pictorial, transparent, intuitively appealing
and well-founded, being sometimes useful for semi quantitative
purposes."
The Sixth International Conference on Miniaturized Chemical and
Biochemical Analysis Systems, known as /JTAS2002, will be fully
dedicated to the latest scientific and technological developments
in the field of miniaturized devices and systems for realizing not
only chemical and biochemical analysis but also synthesis. The
first /JTAS meeting was held in Enschede in 1994 with approximately
160 participants, bringing together the scientists with background
in analytical and biochemistry with those with Micro Electro
Mechanical Systems (MEMS) in one workshop. We are grateful to Piet
Bergveld and Albert van den Berg of MESA Research Institute of the
University of Twente for their great efforts to arrange this
exciting first meeting. The policy of the meeting was succeeded by
late Prof. Dr. Michael Widmer in the second meeting, /JTAS'96 held
in Basel with 275 participants. The first two meetings were held as
informal workshops. From the third workshop, /JTAS'98 (420
participants) held in Banff, the workshop had become a worldwide
conference. Participants continued to increase in /JTAS2000 (about
500 participants) held in Enschede and /JTAS2001 (about 700
participants) held in Monterey. The number of submitted papers also
dramatically increased in this period from 130 in 1998, 230 in 2000
to nearly 400 in 2001. From 2001, /JTAS became an annual symposium.
The steering committee meeting held in Monterey, confrrmed the
policy of former /JTAS that quality rather than quantity would be
the key-point and that the parallel-session format throughout the
3.
Two Symposia on speciation in insects held at the Fourteenth
International Congress of Entomology (Canberra, Australia, August
22-30, 1972) are included in this volume. The first, on the more
general topic of Genetic Analysis of Speciation Mechanisms,
includes four papers on speciation in various groups of Diptera and
Orthopteroid insects. The second symposium was devoted to the topic
of Evolution in the Hawaiian Drosophilidae; it deals with the
explosive speciation of a group of flies with specialized
ecological requirements in the complex ecolOgical habitats provided
by a recent tropical volcanic archipelago. The Hawaiian Symposium,
organized by Professor D. Elmo Hardy, is the latest outcome of a
major collaborative research project involving over 20 scientists
and about 125 technical assistants over a period of ten years. Some
recent books on evolution have taken the standpoint that the funda
mental genetic mechanism of speciation is relatively uniform and
stereotyped and, in particular, that the 'allopatric' model of its
geographic component is universally valid. Certainly, this has been
a rather generally accepted viewpoint on the part of students of
vertebrate speciation. Workers on speciation in insects have
tended, in general, to be less dogmatic and more willing to
consider a variety of alternative models of speciation. Thus, in
the present volume, several contributions adopt viewpoints which
are unorthodox or novel. Only time will tell whether their
conclusions will turn out to have been soundly based."
A New-Generation Density Functional: Towards Chemical Accuracy for
Chemistry of Main Group Elements covers the most recent progress in
the development of a new generation of density functional theory
(DFT) for accurate descriptions of thermochemistry, thermochemical
kinetics, and nonbonded interactions of main group molecules. In
this book, the authors present the doubly hybrid density
functionals (DHDFs), which dramatically improve the accuracy for
predictions of critical properties by including the role of the
virtual (unoccupied) orbitals. The authors not only discuss the
theoretical bases of three classes of DHDFs but also demonstrate
their performance using some well-established benchmarking data
sets.
First-Principles-Based Multiscale, Multiparadigm Molecular
Mechanics and Dynamics Methods for Describing Complex Chemical
Processes, by A. Jaramillo-Botero, R. Nielsen, R. Abrol, J. Su, T.
Pascal, J. Mueller and W. A. Goddard.- Dynamic QM/MM: A Hybrid
Approach to Simulating Gas Liquid Interactions, by S. Yockel and G.
C. Schatz.- Multiscale Modelling in Computational Heterogeneous
Catalysis, by F. J. Keil.- Real-World Predictions from Ab Initio
Molecular Dynamics Simulations, by B. Kirchner, P. J. di Dio and J.
Hutter.- Nanoscale Wetting Under Electric Field from Molecular
Simulations, by C. D. Daub, D. Bratko and A. Luzar.- Molecular
Simulations of Retention in Chromatographic Systems: Use of Biased
Monte Carlo Techniques to Access Multiple Time and Length Scales,
by J. L. Rafferty, J. I. Siepmann, M. R. Schure.- Thermodynamic
Properties for Applications in Chemical Industry via Classical
Force Fields, by G. Guevara-Carrion, H. Hasse and J. Vrabec.-
Multiscale Approaches and Perspectives to Modeling Aqueous
Electrolytes and Polyelectrolytes, by L. Delle Site, C. Holm and N.
F. A. van der Vegt.- Coarse-Grained Modeling for Macromolecular
Chemistry, by H. A. Karimi-Varzaneh and F. Muller-Plathe.-"
The liquid crystalline state may be identified as a distinct and
unique state of matter which is characterised by properties which
resemble those of both solids and liquids. It was first recognised
in the middle of the last century through the study of nerve myelin
and derivatives of cholesterol. The research in the area really
gathered momentum, however, when as a result of the pioneering work
of Gray in the early 1970's organic compounds exhibiting liquid
crystalline properties were shown to be suitable to form the basis
of display devices in the electronic products. The study of liquid
crystals is truly multidisciplinary and has attached the attention
of physicists, biologists, chemists, mathematicians and electronics
engineers. It is therefore impossible to cover all these aspects
fully in two small volumes and therefore it was decided in view of
the overall title of the series to concentrate on the structural
and bonding aspects of the subject. The Chapters presented in these
two volumes have been organised to cover the following fundamental
aspects of the subiect. The calculation of the structures of liquid
crystals, an account of their dynamical properties and a discussion
of computer simulations of liquid crystalline phases formed by Gay
Berne mesogens. The relationships between molecular conformation
and packing are analysed in some detail. The crystal structures of
liquid crystal mesogens and the importance of their X ray
scattering properties for characterisational purposes are
discussed.
This book presents the most comprehensive analysis of bonding in
polyoxometalates and related oxides based on classical bonding
concepts and the bond valence model. Numerous tables and figures
underline and illuminate the results, making it a valuable
resource.
The French chemist Marcelin Berthelot put forward a classical and
by now an often cited sentence revealing the quintessence of the
chemical science: "La Chimie cree son objet." This is certainly
true because the largest number of molecular compounds were and are
continuously synthesized by chemists themselves. However, modern
computational quantum chemistry has reached a state of maturity
that one can safely say: "La Chimie Theorique cree son objet" as
well. Indeed, modern theoretical chemistry is able today to provide
reliable results on elusive systems such as short living species,
reactive intermediates and molecules which will perhaps never be
synthesized because of one or another type of instability. It is
capable of yielding precious information on the nature of the
transition states, reaction paths etc. Additionally, computational
chemistry gives some details of the electronic and geometric
structure of molecules which remain hidden in experimental
examinations. Hence, it follows that powerful numerical techniques
have substantially enlarged the domain of classical chemistry. On
the other hand, interpretive quantum chemistry has provided a
conceptual framework which enabled rationalization and
understanding of the precise data offered either by experiment or
theory. It is modelling which gives a penetrating insight into the
chemical phenomena and provides order in raw experimental results
which would otherwise represent just a large catalogue of unrelated
facts.
Computational methods have become an indispensible tool for
elucidating the mechanism of organometallic reactions. This
snapshot of state-of-the-art computational studies provides an
overview of the vast field of computational organometallic
chemistry. Authors from Asia, Europe and the US have been selected
to contribute a chapter on their specialist areas. Topics addressed
include: DFT studies on zirconium-mediated reactions, force field
methods in organometallic chemistry, hydrogenation of -systems,
oxidative functionalization of unactivated C-H bonds and olefins,
the osmylation reaction, and cobalt carbonyl clusters. The breadth
and depth of the contributions demonstrate not only the crucial
role that computational methods play in the study of a wide range
of organometallic reactions, but also attest the robust health of
the field, which continues to benefit from, as well as inspire
novel experimental studies.
Over the past 40 years, Rotational Isomeric State (RIS) models for
hundreds of polymer structures have been developed. The RIS
approach is now available in several software packages. The user is
often faced with the time-consuming task of finding appropriate RIS
parameters from the literature. This book aims at easing this step
by providing a comprehensive overview of the models available. It
reviews the literature from the first applications of RIS models to
the end of 1994, comprises synthetic as well as naturally orccuring
macromolecules, and tabulates all the pertinent features of
published models. It will help readers, even when not very familiar
with the method, to take advantage of this computationally
efficient way of assessing the conformational properties of
macromolecular systems.
1. R. Carlson, A. Nordahl: Exploring Organic Synthetic Experimental
Procedures 2. S.J. Cyvin, B.N. Cyvin, J. Brunvoll: Enumeration of
Benzenoid Chemical Isomers with a Study of Constant-Isomer Series
3. E.Hladka, J. Koca, M. Kratochvil, V. Kvasnicka, L. Matyska, J.
Pospichal, V. Potucek: The Synthon Model and the Program PEGAS for
Computer AssistedOrganic Synthesis 4. K. Bley, B. Gruber, M.
Knauer, N. Stein, I. Ugi: New Elements in the Representation of the
Logical Structure of Chemistry byQualitative Mathematical Models
and Corresponding Data Structures
Printed Organic And Molecular Electronics was compiled to create a
reference that included existing knowledge from the most renowned
industry, academic, and government experts in the fields of organic
semiconductor technology, graphic arts printing, micro-contact
printing, and molecular electronics. It is divided into sections
that consist of the most critical topics required for one to
develop a strong understanding of the states of these technologies
and the paths for taking them from R&D to the hands of
consumers on a massive scale. As such, the book provides both
theory as well as technology development results and trends.
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