Computational Chemists, as a collection of investigators, have had a problem communicating their results, as well as their value, to the general scientific community. I sometimes suspect that the fog of verbiage and complex explanations typically tendered by computational scientists is designed to hide just how straight forward computer based methods have become! To paraphrase the Wizard of Oz, "Pay no attention to the fellow at the keyboard!"

I have long held with the position found in Professor Jensen's foreword to Introduction of Computational Chemistry that there exists a need to provide an accessible description of the common methods used in computational studies. I believe most bench chemists do want to take advantage of computational techniques, but they don't want to end up looking silly when presenting their work. Questions such as 'Which are the relevant techniques to my situation?', 'How do I compare my results with others?', and 'How can I learn this without suffering through monologues on the "beauty" of projection operators or listening to condescending discussions about the use of the computer mouse?' are, I believe, of interest to the bench scientist. Professor Jensen takes on the ambitious task of addressing this need.

The second chapter provides discussions of the vagaries of the typical molecular mechanics force field in some detail. One finds discussions of the form of the potential, a brief overview of the differences between various popular parameter sets, and information about the actual costs and validity of the calculations. Novices should find a clear picture of many of the terms and methods.

The book reflects Professor Jensen's expertise and interests in as much of the rest of the book focuses upon high-end electronic structure methods and potential energy surfaces and their extrema. The development of the SCF equations and various electronic correlation methods in chapters 3 and 4 are designed to 'illustrate the flow of arguments, rather than focus on the mathematical details.' This middle ground is a challenging target and I suspect that the development will be too complicated for those with equation-phobia and yet lacking for that group that loves detail. It is very difficult to please everyone.

The discussion of basis sets in chapter 5 is a very useful resource. It provides a detailed outline of the difference between various basis sets typically used. There is also a nice explanation of the confusing naming conventions. Bravo!

Chapter 11 attempts to illustrate the application of some methods. But after reading this I mst admit that the fantastic amount of work required to correctly determine the properties of simple molecules such as water left me, a 14 year practitioner, to wonder about the utility of our methods for molecules of interest to chemical industry and pharmaceutics!

Chapter 14 provides a fine discussion of the methods for traversing the potential energy surface. Professor Jensen's expertise yields clear discussions of the many techniques used to search for particular points on the molecular energy surface: very useful for researchers looking beyond the nearest local minimum.

Other chapters introduce density functional theory, valence bond methods, relativistic methods, and wave-function analysis. Chapter 10 nicely outlines the molecular properties available to electronic structure techniques. There are also brief introductions to transition state theory, statistical mechanics, and normal coordinate analysis and the calculation of molecular vibrations. Finally, there are discussions of various qualitative models of reactivity and an overview of simulation methods, both classical and quantum.

My main concern about the book is that the presentation does not maintain a consistent cohesion, with the discussion jumping about at times from idea to idea. The volume present itself too often to me as a 'grab-bag' of information. While this might frustrate the individual who is reading for enlightment, a well structures curriculum could make good use of the contents as starting points for further discussions. There was, perhaps, less balance than I would have liked in the presentation. I found some concepts too quickly dismissed (e.g. pseudospectral methods or wavefunction analysis) and others too readily embraced (e.g. the assumption upon which Koopmans' theorem is based or electronic structure being superior to force field methods). But, as always, it is much easier to complain than to do.

As professor Jensen concludes, "The key is therefore to evaluate what level of theory ... is required to obtain results which are sufficiently accurate to provide useful information about the question at hand." While I'm not convinced that this book succeeded in providing the definitive general reference for this goal, this book is a sturdy graduate-level introduction to electronic structure methods.

Keith Laidig.