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An Introduction to Theoretical Chemistry. By Jack Simons

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Angewandte
Books
Chemie
An Introduction to Theoretical
Chemistry
By Jack Simons.
Cambridge University Press, Cambridge 2003.
461 pp., hardcover
£ 29.95.—ISBN
0-521-53047-4
Anyone writing an introduction to theoretical chemistry must first decide what
proportion of the contents will be
devoted to the presentation or derivation of results. The author of this textbook has chosen to adopt a very unorthodox ratio of theory to results. In his
preface Simons makes it clear beyond
doubt that from this textbook the
reader will learn mainly theory. The
book is divided into two parts. In the
first part Simons deals with “background material”, which mainly consists
of standard examples and results from
quantum mechanics. The second part
contains four chapters in which the
author first discusses the relationship
between theory and experiment, then
treats quantum-mechanical methods in
greater depth and, interestingly, adds
further discussions about statistical thermodynamics and kinetics.
In Part 1, a short introduction is followed by the Schr$dinger equation as a
theoretical postulate. The equation is
then applied to the particle-in-a-box
problem and to hydrogen-like atoms.
In connection with the extension to molecules, the Born–Oppenheimer approximation is described, and later the
H)ckel theory is developed for polyenes. Next the author presents the treatment of rotations and vibrations, and
Angew. Chem. Int. Ed. 2004, 43, 923 – 924
this part ends by describing perturbation
theory, variational methods, and the
application of point symmetry properties.
Part 2 begins with general considerations about bond-lengths, molecular
structures, and experimental methods
for determining these. The Woodward–
Hoffmann rules and the methods of statistical mechanics are also introduced.
The following chapter gives a superficial description of the Hartree–Fock
mechanism, and in that connection
basis sets and molecular orbitals are
introduced. A discussion of the shortcomings of the Hartree–Fock formalism
leads into a clearly presented development of the configuration–interaction
approach. The chapter continues with
brief descriptions of the coupled-cluster
method, perturbation theory, MonteCarlo methods, and the r12 method. Density functional theory is discussed at
great length, but not very clearly, and
the author even gives a proof of the
Hohenberg–Kohn theorem. As the
latter proof is not constructive in leading
anywhere useful, its inclusion is not very
informative for the budding theoretician. The chapter ends with a discussion
of the theory of spectroscopic methods
applied to molecular-structure determination.
The penultimate chapter breaks
away from the pattern of the preceding
ones, as it is entirely devoted to statistical thermodynamics. Methods based on
the sum-of-states are developed, and
the author also discusses the use of
MonteCarlo methods and molecular
dynamics simulations for calculating
thermodynamic properties, and for
applications to the themodynamics of
gases, liquids, and crystals.
After another break, the last chapter, on kinetics, begins with transitionstate theory. Then MD simulations, the
RRKM theory, and wave-packet propagation are explained very briefly, and
the chapter ends with a similarly brief
discussion of detection mechanisms for
chemical reactions.
On the whole one can find one's way
around the book very easily by using the
list of contents. The author has made a
particular effort to avoid having the
reader distracted by the need to turn
pages back and forth, and for that
reason he often repeats results that
www.angewandte.org
appeared earlier in the book. Thus the
book is well suited for the reader who
wants to learn quickly about a specific
topic. As is apparent from the earlier
comments, parts of the book seem
rather disjointed, especially in Part 2.
This tends to confuse the reader rather
than giving a better understanding of
the complex subject, which conflicts
with the purpose of a textbook.
Unfortunately Simons decided to
collect the exercise problems together
at the end of the book (without an indication of the chapter to which they
belong), instead of integrating them
into the text. Consequently the book is
not suitable for individual study, and
even for a course tutor the chore of
searching for suitable problems to set
could be a tedious irritation. However,
the answers to the problems are also
grouped together after the problems
themselves, and therefore the course
tutor is forced to look elsewhere for suitable homework exercises, whereas this
arrangement is very instructive for the
student working individually.
Concepts such as “quantization”,
“hermiticity”, and “orbital” are mentioned without much explanation in
Part 1, which is inappropriate in an
introductory text such as this, and will
make it difficult for the student to
understand the discussion, as also will
the use of the commutator “[,]”.
Another confusing usage is the description “non-zero”, when what is actually
meant is that the quantity in question
does not necessarily have the value zero.
In his introduction Simons explains
that he has intentionally avoided giving
literature references, apart from a few
that are mentioned in the preface, and
he refers the reader to his homepage
on the WorldWide Web. There, in
URL, the complete book is available
as a PDF file in color, in contrast to
the actual book, which only has gray
tones. The author's more advanced
book Quantum Mechanics in Chemistry
is also available in the same place in
complete form as a PDF file.
Simons covers many different
aspects of theoretical chemistry in this
book, and he puts great emphasis on
the difference between classical
mechanics and quantum mechanics.
Unfortunately the text contains a few
mistakes: for example, in Formulas 1.22
( 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
923
Books
and 1.23ff the factor 2m has been omitted, which is likely to confuse readers
with no previous knowledge of the subject. However, the text flows easily for
reading and conveys an enormous
amount of knowledge, mainly in a concise and clear way.
B. Christopher Rinderspacher
Center for Computational Quantum
Chemistry
University of Georgia, Athens (USA)
DOI: 10.1002/anie.200385028
Magnetic Resonance in Chemistry
and Medicine
By Ray Freeman.
Oxford University
Press, Oxford 2003.
278 pp., hardcover
£ 32.50.—ISBN
0-19-926225-X
What is the connection between saturation of an NMR signal and a bank overdraft?—or between pulse-FT NMR and
the crash of a grand piano landing on a
hard concrete floor? And how does a
large giraffe fit through a small
“window”? NMR aficionados can
guess now that the subject of this
review will be the new book by Ray
Freeman. Its title (“… in chemistry and
medicine”) points to a parallel presentation of the basics of NMR spectroscopy
and magnetic resonance imaging
(MRI). In contrast to his Handbook of
Nuclear Magnetic Resonance“ (2nd ed.,
1997), which was organized in alphabetical order, Freeman has now chosen a
textbook format, with the chapters
arranged in a logical order that allows
one to study by reading the book in
sequence.
Almost exactly the first half of the
book comprises several general chap-
924
ters, which present the basic properties
and concepts of nuclear magnetic resonance, namely excitation and detection
of NMR signals, relaxation, sensitivity,
resolving power, chemical shift, spin–
spin coupling, and spin echoes. The
author's explicit intention here is to
convey a fundamental understanding of
the NMR phenomenon without relying
on complicated quantum-mechanical or
mathematical formalisms. Some readers
(with the necessary skills at hand) might
prefer a mathematically clear deduction
here or there—but Ray Freeman almost
always manages to offer descriptive
explanations (interspersed with a pinch
of fine humor) that are perfect equivalents.
The second half of this book comprises more specialized chapters on
either more chemically orientated applications (solid-state NMR, two-dimensional spectroscopy) or medical uses
(MRI/imaging, in vivo spectroscopy,
NMR of body fluids, and functional
MRI). Again, in these quite ambitious
chapters the emphasis is on “descriptive” explanations; however, more
demanding aspects such as pulse
sequences or k space are not avoided.
An additional chapter deals with the
safety aspect of MRI examinations.
Overall, Ray Freeman's concept is
quite convincing: many cross-references
between the subchapters help integrate
the basic principles and the chemical
and medical applications, thus largely
avoiding repeats in the whole book.
Numerous figures help clarify the
explanations (although, unfortunately,
such help is not given in the part on
“NMR in two frequency dimensions”);
sometimes a few more labels in the figures would have helped even more.
The spectra and MRI images shown
are of consistently high quality and
very helpful.
Naturally, some errors can be found
in a book of this kind—for example,
the natural abundance of deuterium is
0.015 %, not 1.5 %. The emphasis on
descriptive explanations leads to some
inaccuracy: multiple-quantum transitions are not generally forbidden, just
not directly observable. Also the “dancing 13C lines” in Figure 8.5 are misleading—heteronuclear decoupling relies
( 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
merely on a fast averaging of the doublet signal. Directly annoying—in the
eyes of this reviewer—is the section on
“chemical shift/referencing”, with a 1H
“shielding scale” running from left to
right with tetramethylsilane (TMS) at
“t = 10 ppm”; also the scheme depicting
typical 1H shifts starts with aldehydes at
d = 0 ppm (left edge) and ends with
methyl groups on the right side at
about d = 9 ppm! This historical
“t scale” can only cause confusion for
the reader—and indeed, all the example
spectra shown in this same book use the
“d scale” (running from right to left,
with TMS at 0 ppm), which has long
been customary.
In addition to the literature references in the appendix, many chapters are
followed by a short list of “further reading”. Unfortunately, some of these
books—although also highly appreciated by this reviewer—have been out
of print for several years and can only
be found in some libraries, e.g., Fourier
Transform Spectroscopy by Shaw
(1984) and Modern NMR Techniques
for Chemistry Research by Derome
(last edition 1993, not 1987).
Who will profit from reading this
book? First of all, students as well as scientists and physicians longing for a quite
profound insight, not only into the basic
concepts, but also the modern applications of nuclear magnetic resonance.
Of course, people interested in more
details—and perhaps in doing experimental work themselves—will need
additional, more specialized literature
(using a more formalistic treatment),
but they will also benefit from the
descriptive and intuitive access offered
by Ray Freeman's book. Last but not
least, the book will provide valuable
suggestions to everyone involved in
teaching NMR to chemists and physicians.
Gerd Gemmecker
Institut f:r Organische Chemie und
Biochemie II
Technische Universit<t M:nchen
Garching (Germany)
Angew. Chem. Int. Ed. 2004, 43, 923 – 924
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