Bo o k s
A new classic
Vibrational Intensities Boris S. Galabov and Todor Dudev Elsevier Science P.O. Box 945 New York, NY 10159-0945 1996, 342pp,, $240.75
IR and Raman intensities are fundamentally related to molecular electronic structure. Although these intensities can be experimentally determined with good accuracy, the information content is seldom fully exploited. One reason is the lack of a clear, up-to-date critical evaluation of available methods for calculating vibrational intensities. This monograph addresses this problem, superseding the classic—but dated— collection of reviews entitled Vibrational Intensities sinnfrared ana RaRam Spectroscopy, edited by Person and Zerbi. Although the emphasis in that collection was on fundamentals and experimental measurements (Zerbi's Chapter 3, entitled "Introduction to the Theory of Vibrational Frequencies and Vibrational Intensities", remains the gold standard), this new monograph stresses fundamentals in Chapters 1-6,8, and 9 and computational methods in Chapters 7 and 10. Experimentalists seeking reliable approaches for measuring absolute Raman cross tions for example will not be satisfied with the four-page treatment and references through only the mid-1970s A solid understanding of quantum mechanics at the graduate level is assumed. 618 A
Chapters 1-7 on IR intensities comprise the first two-thirds of the book, and chapters 8-10 on Raman intensities make up the remainder. Chapters 1, 2, and 8 review perturbation theory, symmetry, coordinates in vibrational analysis, and the fundamental origins of vibrational intensities. A handy feature of Chapter 2 is the summary of vibrational coordinates and their transformations. The text and notation are clear, and they present a readable physical picture; but newcomers to the field might wish to consult the classic texts entitled Molecular Vibrations: The Theory of Infrared and Raman Vibrational Spectra
authors make a case for developing transferable intensity parameters, analogous to vibrational force fields, for simulating large molecules such as proteins. Nevertheless, most chemists who need to calculate intensities will no doubt turn to one of the commercially available software programs. For them, Chapters 7 (IR) and 10 (Raman) provide a well-written critical introduction to ab initio methods. Galabov and Dudev briefly summarize the methods available; explain basis set notation; the quality of the results obtained for C0 , HCN, and larger molecules at different levels of theory; and provide excellent guidance on performing and critically interpreting the calculations The book contains separate subject and author indices. The subject index contains entries for acronyms of computational methods and basis sets—a useful feature. The bibliography was somewhat disappointing, however, because only 25% oo the references are post-1984 and less than 10% are from the 1990s. This sparseness may account for the authors' rather conservative view of the future of quantum mechanical methods for calculating vibrational intensities. The tremendous recent advances in hardware speed and software user-friendliness (e.g., Gaussian94 aan the GaussView and Spartan graphical interfaces to quantum mechanical program packages none of which are mentioned) have made performing high-quality intensity calculations much more accessible than would be at> parent from this book
The inclusion of example molecules and a critical interpretationofthe results are well done. by Wilson, Decius, and Cross and Introduction tt the Theory of Molecular Vibrations and Vibrational Spectroscopy by Woodward to get started. The chapters on semiclassical and atomic polar tensors models for IR intensities and parametric models for interpreting Raman intensities do not contain much new information. However, the inclusion of example molecules and a critical interpretation of the results are well done. The discussion of bond-polar parameters and the application of this model to larger molecules (up tofivenon-hydrogen atoms) is current but nevertheless it reflects the authors' bias that direct ab initio quantum calculations cannot yet readily be applied to these and larger systems. In Chapters 5 (IR) and 9 (Raman), the
Analytical Chemistry News & Features, October 1, 1997
The volume is a useful reference for libraries and practitioners. It is hoped that readers will not be deterred by the authors' cautionary tone regarding quantum chemical calculations on large systems. Such calculations can, indeed, be performed on molecules of analytical interest, even by relative novices, opening the door to fuller use of vibrational intensity information. Reviewed by Robin Garrell, UCLA. S0003-2700(97)09034-3 CCC: $14.00 © 1997 American Chemical Society
