is incorrect; diastereotopic protons remain diastereotopic, the shift difference between HA and He may be very small or almost zero depending on the population of conformers present, but equal energies of the conformers are neither necessary nor sufficient for this. These criticisms should not, however, destroy the positive overall impression made by the book. The reader’s first impression is of a useful compendium of literature. He may then be fascinated by a single topic and finally he is successfully made aware of the possibilities offered by DNMR spectroscopy for his own research. Martin Feigel [NB 748 IE] Institut fiir Organische Chemie der Universitat Erlangen-Niirnberg (FRG) Vibronic Coupling. By G . Fischer. Academic Press, London 1984. viii, 222 pp., bound, $ 42.00. - ISBN 0-12-257240-8 In recent years, the significance of vibronic coupling (i.e., the interaction between electronic and nuclear motion in molecules) for spectroscopy and for many dynamic processes has become increasingly evident, as reflected in the growing number of publications o n this subject. Accordingly, there is keen interest in a book that documents the current status of research in this field and also gives the nonspecialist guidance. The monograph under consideration is primarily intended for the nonspecialist. It therefore begins in Chapter 1 with an elementary demonstration of the separation of variables in several systems, which should facilitate a n understanding of the adiabatic approximation. In the following two chapters, this approximation is discussed for diand polyatomic molecules. In order to extend the treatment and be able to describe “intensity borrowing” and nonadiabatic effects, variants of the adiabatic approximation and other methods, mainly from perturbation theory, come u p for discussion. Two approaches to the calculation of transition intensities in electronic spectra (that of dipole length and that of dipole velocity) are compared in Chapter 4. Chapter 5 concludes the general part of the book with a presentation of two symmetry-dependent degeneracies, the Jahn-Teller and the Renner-Teller effects, which are classical examples of vibronic coupling. In Chapters 6-8, the most important applications come u p for discussion : the calculation of vibronic-coupling effects using semiempirical (CNDO) methods as well as the manifestation and detection of these effects in electronic spectra and in multiphoton processes. Important dynamic processes in which vibronic coupling plays a role-in particular, radiationless decay-are discussed in Chapter 9. The book closes with a survey of analogous effects in molecular crystals. O n the whole, one can recognize the effort that the author has made to present the manifold applications of vibronic coupling in a way that is also understandable to the nonspecialist. Nevertheless, this effort cannot be considered successful for several reasons. First and foremost, attention must be called to the selection and organization of the material. Questions that are only very loosely related to the subject of the book, such as local modes, energy transfer, and unimolecular reactions, are discussed. O n the other hand, important newer developments, such as the concept of the so-called diabatic electronic wave functions, the appearance of strong nonadiaAngew. Chem. I n t . Ed. Engl. 25 (1986) No. 7 batic effects when potential surfaces intersect conically, and the calculation of vibronic-coupling effects using truly ab-initio methods, are not even referred to. Furthermore, many standard references are missing, and only little experimental material is presented to illustrate the meaning of the effects discussed. The material is not very clearly organized. Thus, the basic coupled equations of electronic and nuclear motion are newly derived in each of the Chapters 2, 3, and 5 ; the socalled Herzberg-Teller expansion for the transition moment in each of the Chapters 3, 4, and 6. Without crossreferences, such repetitions are not only superfluous, but also, at least for the beginner, even disorienting. The assignment of the material to the individual chapters is in part illogical; Chapter 7, for example, seems out of place-thematically, it belongs to either Chapter 6 or 8. The unsystematic arrangement of the material makes it extraordinarily difficult to obtain a general view of the effects of vibronic coupling and of their connection. Why, for example, in Chapter 5, which is on the Jahn-Teller effect, is the opportunity not taken to make its relation to adiabatic potential surfaces clear by discussing calculated model spectra? O n the whole, the book gives the impression (though unfounded) that one can almost always describe nonadiabatic effects using perturbation theory, and it is incomprehensible, for example, why an example is cited in Section 6.5 of the “Breakdown of the Born-Oppenheimer approximation,” precisely where this approximation does not break down. The list of shortcomings is rounded out by the numerous minor oversights and mistakes, which have crept into the text. One example is the false definition of the term “electrical anharmonicity” on p. 106; a more serious example is the discussion of the potential surfaces of a vibronic system with several nuclear vibrations, where the multimode effect is simply overlooked (p. 84). In summary, a book that is only marginally suited for the introduction of the beginner to the field in question. Horst Koppef [NB 721 IE] Physikalisch-Chemisches Institut der Universitat Heidelberg (FRG) Thermodynamik irreversibler Prozesse. Eine Einfiihrung. By H.-W. Kammer and K . Schwabe. VCH Verlagsgesellschaft, Weinheim 1985. 114 pp., Brochure, DM 28.00.ISBN 3-527-21 104-7 This thin volume addresses physicists and chemists who wish to acquire first knowledge about thermodynamically irreversible processes. After the Introduction, which outlines the contents of the book very briefly, a short summary of equilibrium thermodynamics is given. Next, the fundamental concept of entropy production is introduced by means of two examples (solidification of supercooled water and thermal conductivity) and then generalized to processes with a single order parameter as well as to chemical reactions. In the short, fourth chapter, the dynamics of irreversible processes are discussed using the example of glass transitions in polymers. This chapter seems to me to be too complicated for a n introductory text; furthermore, the mathematical treatment does not impart any knowledge that could not be equally well obtained in a simple qualitative manner. The next chapter deals with Onsager’s reciprocal relationships. Thermoelectrical effects and thermodiffusion are thoroughly discussed; on the other hand, 659

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