*Density Functional Theory: A Practical Introduction,*John Wiley & Sons, Inc., 2009, ISBN-13: 978-0470373170, 232 pp.

^{1}

^{,}

^{2}who, broadly speaking, transformed the quantum problem of a system of interacting electrons to the comparatively simple problem of a system of noninteracting electrons subject to an effective potential that (in principle) faithfully captures the original system's "many-body" attributes.

^{2}to more recent volumes by Richard Martin

^{3}and Jorge Kohanoff.

^{4}However, most of these books emphasize theory, even in their discussions of techniques and applications. This isn't a criticism; a solid understanding of the theoretical underpinnings of DFT and its applications is essential for a serious practitioner. However, none of these books provides an entry point to the subject—that is, a practical introduction for newcomers or outsiders needing a reading readiness of what DFT can and cannot do. Filling this lacuna is

*Density Functional Theory: A Practical Introduction*by David S. Sholl and Janice A. Steckel.

*any*newcomer to DFT.

*is*somewhat biased toward a subset of the full DFT community—albeit quite a large one.

• examples from the research literature showing DFT's contribution to diverse fields,

• a brief introduction to the Hohenberg-Kohn-Sham theory that underlies all DFT methods,

• an overview of the broader quantum chemistry field and DFT's place within it,

• a discussion of what DFT *can't* do, and

• advice to readers on how to approach the book.

*k*-point sampling, plane-wave cutoffs, optimization algorithms, self-consistency, and structural optimization. Throughout, the authors emphasize the importance of convergence testing for numerical approximations and give several illustrative examples.

• highlights the major categories of exchange-correlation functionals in use today,

• discusses the typical physical accuracy to be expected for various physical properties, and

• introduces phenomenological extensions to DFT designed to improve the treatment of electron correlation.

• Chapter 2 addresses using DFT to compute stable (or metastable) structures, using simple solids to illustrate the approach;

• Chapter 5 focuses on calculating vibrational normal modes and frequencies with DFT; and

• Chapter 8 considers electronic and magnetic structure.

*ab initio*thermodynamics method for predicting equilibrium compositional phase diagrams. The last application chapter, Chapter 9, discusses the

*ab initio*molecular dynamics (MD) method. Broadly speaking,

*ab initio*MD is the same as classical MD, but with atomic forces calculated at each time step via DFT instead of a classical force field.

*Density Functional Theory: A Practical Introduction*is one that I've yet to mention: the exercises provided at the end of every chapter (except the first and last). As I often tell my students, "You can't learn how to play basketball simply by reading about the rules and strategies or watching other people play; you have to go out and practice the skills." The same holds for DFT. Sholl and Steckel emphasize this point and have chosen good, tractable end-of-chapter practice exercises. Some exercises give clear, well-defined problems, while others are more open-ended, leaving it to the reader to find a good solution. Given the wide availability of computing resources and good, well-documented (and sometimes free) plane-wave DFT codes, readers should find it easy and convenient to roll up their sleeves and dig in.

*Density Functional Theory: A Practical Introduction*that

*CiSE*provided, I went out and bought a second copy for my own research group. This book is not perfect, but it

*is*good. And it is the

*only*book at the right level for a DFT newcomer.

#### References

**Steven P. Lewis**is an associate professor of physics at The University of Georgia and more than 20 years of experience as a DFT practitioner. His current research focuses on nanostructured materials, molecule/surface interactions, and photorefractive oxides. Lewis has a PhD in physics from the University of California, Berkeley. Contact him at lewis@physast.uga.edu.

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