Cryst. Growth Des. 2009, 9, 2537
2537
Book ReViews Powder Diffraction: Theory and Practice. Edited by R. E. Dinnebier and S. J. L. Billinge, Cambridge, UK. 2008. 582 pp. List price $129. ISBN978-0-85404-231-9. The dynamism of today’s powder diffraction is reflected by publication in the last few months of three introductory works on the topic: this book; Principles and Applications of Powder Diffraction edited by Clearfield, Reibenspies, and Bhuvanesh; and a new second edition of Pecharsky and Zavalij’s Fundamentals of Powder Diffraction and Structural Characterization of Materials. Dinnebier and Billinge sought to write an advanced introductory text on modern methods and applications of powder diffraction. This book does not discuss basic crystallography or diffraction, and indeed the authors refer the reader to Pecharsky and Zavalij for that information. The editors have assembled an appropriate team of experts to introduce the quantitative analysis of powder patterns, with the aim of extracting the maximum information from the data. The analysis includes not just the intensities of the Bragg peaks, but their shapes and the background. Chapter 1 “Principles of Powder Diffraction” (Dinnebier & Billinge) is a compact and correct summary, but the true beginner will need more information from Pecharsky & Zavalij. A particularly useful section is on derivatives of the Bragg equation, which make it easy to discuss several phenomena. The dense discussion in Chapter 2 of “Experimental Setups” (Jeremy Cockroft and Andrew Fitch) concentrates properly on modern instrumentation. It contains more than the usual information about synchrotrons and neutrons, reflecting their growing importance in even the normal practice of powder diffraction. This chapter is marred by several misuses of principle/principal. The authors of Chapter 3 “The Intensity of a Bragg Reflection” (Bob Von Dreele and Juan RodriguezCarvajal) are the authors of two of the principal Rietveld programs, so they should understand the topic! This chapter contains a useful introduction to aperiodic structures (with appropriate references), and more than the usual introductory material on magnetic structures. With the increasing use of the Rietveld method, a chapter (4) on “General Data Reduction” (Rudolf Allman) might seem old fashioned, but the ideas are important to the practice of classical powder diffraction, especially indexing and quantitative phase analysis. I wish there were more examples showing how variations in data reduction can change both the position and intensity of a peak. There is a useful discussion of systematic errors and their correction, but I wish it were more extensive. In Chapter 5 “The Profile of a Bragg Reflection for Extracting Intensities”, Armel Le Bail gives a combination of theoretical and empirical approaches to describing a peak profile, and summarizes the current limits of the fundamental parameters approach. He gives a short summary of old ideas and gives a useful summary of the mathematics and physics which go into determining line profiles. This discussion could easily be expanded into a complete book! Le Bail describes the algorithms of whole pattern decomposition by both the Pawley and Le Bail methods, and why one wants to use this technique. The discussion makes this chapter a better reference to the Le Bail method than that usually cited (which does not actually discuss
the method). I wish that Chapter 6 “Instrumental Contributions to the Line Profile in X-ray Powder Diffraction. Example of the Diffractometer with Bragg-Brentano Geometry” (Alexander Zuev) were integrated with Chapter 5, and that its level of mathematical detail were also applied to the traditional approaches for describing line profiles. In many Rietveld refinements, one spends most of the effort trying to get the profiles right, so an advanced text should contain a full understanding of the mathematics and physics behind line profiles. Chapter 7 “Indexing and Space Group Determination” (Angela Altomare, Carmelo Giacovazzo, and Anna Moliterni) gives an excellent discussion of the mathematics behind the most-used classical algorithms as well as newer methods for indexing and space group determination. Chapter 8 “Crystal Structure Determination” (Rocco Caliandro, Carmelo Giacovazzo, and Rosanna Rizzi) contains an excellent brief summary of the main methods used to solve structures, and refers to Giacovazzo’s large IUCr text for more detail. The introduction to “Rietveld Refinement” (Bob Von Dreele) in Chapter 9 gives the mathematics of least-squares, discusses the mathematics of constraints and restraints, and summarizes the current state of refinement of protein structures using powder data. This chapter is not the step-by-step introduction to the practice of Rietveld refinement that a beginner might need. Chapter 10 (Leonid Solovyov) describes “The Derivative Difference Minimization Method”; time will tell how useful this will be. Ian Madsen and Nicola Scarlett (organizers of the IUCr round robins on quantitative phase analysis) summarize the mathematics and sources of error in Chapter 11 “Quantitative Phase Analysis”, as well as provide examples. This discussion of the mathematics of microabsorption should be useful to those for whom Brindley’s 1945 paper is difficult to obtain. In Chapter 12 “Microstructural Properties: Texture and Macrostress Effects” Nicolae Popa provides an excellent summary of the mathematics of the March-Dollase and spherical harmonics approaches to describing preferred orientation, as well as the intimidating-looking math of macrostress/strain. Paolo Scardi (author of a whole book on the topic) gives a dense summary of the mathematics of line profile effects due to size, strain, and defects, as well as summaries of the WilliamsonHall, Warren-Averbach, and Whole Powder Pattern Modeling approaches in Chapter 13 “Microstructural Properties: Lattice Defects and Domain Size Effects”. In Chapter 14 ”TwoDimensional Diffraction Using Area Detectors“ Bernd Hinrichsen, Robert Dinnebier, and Martin Jansen summarize current area detectors and the transformations involved in using them. I am surprised that there was not more discussion of their current work on obtaining one-dimensional powder data from these “detectors of the future”. Paul Norby and Ulrich Schwarz summarize the tools and techniques for performing “Powder Diffraction under Non-Ambient Conditions” in Chapter 15. As we would expect in a book with Simon Billinge as an author, Chapter 16 discusses “Local Structure from Total Scattering and Atomic Pair Distribution Function (PDF) Analysis”. This chapter succeeds at making this approach less intimidating for beginners. Lachlan Cranswick was the brave soul who compiled Chapter 17 “Computer Software for Powder Diffraction”. Such
10.1021/cg9001303 CCC: $40.75 2009 American Chemical Society Published on Web 03/11/2009
2538
Crystal Growth & Design, Vol. 9, No. 5, 2009
a listing is out-of-date as soon as it is compiled, but the chapter is comprehensive. Potential users of powder diffraction software should always consult the CCP14 Web site for current versions. How does this book fit into the current universe? Each of the three new books sets out to achieve something different. A beginner should start with Pecharsky & Zavalij for the basics, then move to Clearfield, Reibenspeis, and Bhuvanesh for an introduction to the more advanced topics (particularly the uses of powder diffraction and more detail on Rietveld refinement), and then use Dinnebier and Billinge for the mathematical details
(although I wish there were more). Though you cannot avoid having all three in your library, this book should prove to be the most useful reference for advanced users. James A Kaduk INEOS Technologies, NaperVille, IL CG9001303 10.1021/cg9001303
