The chapters follow on logically, initially discussing the decisions to be made prior to undertaking a research project, with subsequent advice on the planning and time management of the project itself, and some of the later chapters giving advice on the oral and written presentaion of scientific work. In addition to the more general points of interest, there is some discussion on topics of a more practical nature, which are therefore of use to refer to at a later date.
The author clearly states that many of the points made will seem obvious to the majority, but unfortunately this may make some of the discussion appear slightly laboured, however, the reader may be inspired to give more thought to some issues before making some very important decisions or commitments.
The book is well laid out and easy to follow, with quick reference to different sections. If you are new to research, then will certainly find it a source of much sound advice on how to go about organising yourself. Nevertheless, with the financial limitations of a student grant, the retail price of #9.95 could perhaps be deemed excessive, as you may find that much of the information can also be obtained from other sources, such as your own department, fellow research workers and supervisors.
Graeme Bell, Biochemistry Dept, University of Bath, 2 May 96
The First Edition was reviewed in detail in Acta Cryst ( 1984), A40, 86-87. The reviewer noted a few misprints and inconsistencies, but overall thought the book was good value.The Second Edition was reviewed in Acta Cryst (1995), A51, 590. This reviewer concentrated largely on the new chapter on Fast Fourier Transforms, but also commented on the readability of the book.
For readers not comfortable with mathematics, the first impression on opening the book may be daunting. However, it is worth persevering, (perhaps putting off following the mathematics for some future reading) just in order to get the insights described in the text. For example, there is a demonstration of the substantial equivalence of F and F~ refinement, and an exposure of the hazard of asking whether a group of atoms is significantly coplanar when the only information to hand is the result of an un- constrained refinement (A better question is to ask whether a planar model is compatible with the X-ray data - a reader determined to follow the first alternative should also look at the articles by Sands and Marsh & Schomaker in International Tables, Volume B). A substantial part of the book is devoted to the problems of data fitting, modelling and the significance and interpretation of results. Throughout, the reader is made aware of the dangers of applying mathematics unthinkingly. Since many of the processes described in the book lie at the heart of modern computer programs, it should greatly help users get the best from the programs.
For anyone developing crystallographic software, this book is a mine of valuable information. Much of it does exist elsewhere in the literature, but it could be very time consuming to locate it - assuming its existence was known of.
This is a first rate little book, and every active crystallographer should have access to it.
David Watkin, University of Oxford
The tape and booklet forms Part II of a two part course on X-ray Crystallography, as an introduction to the use of X-rays in Chemistry, at an undergraduate level. Part I, 1989, introduced X-ray powder and single-crystal techniques, the Bragg equation, the amplitude and phase angle of waves, systematic absences, crystal systems, Miller Indices and the P21/c space group. Part II develops further the calculation of the phase angle, a, the structure amplitude, |F|, and how these contribute to the solution of X-ray structures by Trial and Error Methods, the Patterson Method and by Direct Methods. Part II consists of a cassette tape, a 56 page booklet, 30 frames of text and Figures, and 10 problems, with detailed worked answers provided. The tape provides nearly two hours of listening time and the numerical problems take three hours to work through, if the optional problem on triple phase selection is omitted.
The cassette and tape would form an excellent basis for a tutorial course to accompany a final year lecture program on X-ray Crystal Structure Determination, especially for good students with a mathematical background, who enjoy problem solving, as the first five problems represent one of the best applications of Fourier series to X-ray crystallography available. The summation of Fourier series, the explanation of the origin of the phase angle, Problem 3, the calculation of the multi-component structure amplitudes, |F|, Problem 4, and the construction of the corresponding Argand diagram, Problem 5, are all extremely informative. The sections on the Trial and Error Methods, the Patterson Method and the Direct Methods, strongly reflect the authors background in Physics, but are clearly described and serve to illustrate the historical development of X-ray structure solution.
At a time when the "Black Box" approach to structure solution predominates in the undergraduate teaching program, it is nice to see an attempt made to get back to the basic physics of crystallography, presented at the undergraduate level, especially the account of the application of the Direct Methods. If there is a criticism of the text the choice of an I and Br atom containing structure, Problem 7, to introduce the Heavy Atom Method, does seem a little abstruse. At an undergraduate level, a single heavy atom structure in the P21/c space group, would be advantageous, as it would have required an explanation of how the four equivalent positions of the heavy atoms are connected to solve the Patterson Fourier. It was also surprising that the concept of reciprocal lattice space was not introduced, if only to illustrate how systematic absences can be used to distinguish P, I, and F type unit cells and the presence of screw axes and glide planes in a space group. If the aim of the cassette is to help readers of crystal structure papers, the final section on refinement justifies expansion. Such readers may find the level of mathematics required rather daunting and might justify transfer of some of the more demanding mathematical sections to an appendix. Notwithstanding, X-ray Crystallography, Part II is strongly recommended as an excellent supplementary teaching material, to a final year course on X-ray Structure Determination.
March 1996 - Brian Murphy� and Brian Hathaway�. The Chemistry Department�, University of Wales, Cardiff and The Chemistry Department�, University College Cork, Republic of Ireland. � Tel.: (01222) 874000 Ext. 5840; Fax: (01222) 874030; E-mail: [email protected] � Tel.: 00 353 21 276871; Fax: 353 (0) 21274097; E-mail: [email protected]
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