There are 6 reviews in this issue:
Werner Massa, Marburg University, Germany (English translation by Robert Gould)
Springer Verlag, 2000.
Price £24.00 (softcover)
ISBN 3-540-65970-6, xi+206 pp
One trepidation about writing a review on the English edition of Werner Massa's "Crystal Structure Determination" is that it cannot do justice to the conciseness and clarity of this highly useful single-crystal crystallographic text. It not only provides a very clear exposition of crystallographic theory, but also the practise and "real world" tricks, hints and expectations of what is possible. Starting with the crystallographic theory (and various tricks and limitations of the method); it continues onto experimental methods (including the growing of crystals); mounting and indexing the cell; structure solution; structure refinement; additional topics such as absolute structure, extinction and the lambda/2 effect, etc; errors and pitfalls, disorder, false unit cells, twinning, false spacegroups, misplaced origins, etc; interpretation and presentation of results; crystal structure databases; and finally a worked structure solution using SHELX.
While some crystallographers might put the charge of "corrupting the youth" on the author by his emphasizing the use of F-square intensity data over F's for structure solution and refinement; there is almost nothing significant on which to try and condemn this book. It is excellent. Though trying to find some criticisms; an extra emphasis on the use of CCD diffractometers and the various practical pitfalls and tricks of the trade in using CCD instruments would be useful. Another addition could be to point out the quite sophisticated automatic validation options in CIFCHECK as well as Platon, and how to interpret and make use of the validation output (different alert levels, A, B and C). Given the usefulness of the Worked Example of solving and refining a structure using SHELX, it could be nice to have worked examples of other programs showing their different approaches and advantages - but this is a personal and probably unimportant comment.
Another issue is that of the price. At £24.00 EUR 39.95, it is affordable by individuals (though half that cost would probably be nicer for the student budget). This price compares in a favourable manner to recent trends in published scientific texts that have the apparent primary aim of being a rip-off, rather that a useful scientific text deserving of being read. A possible equivalent of the Massa book in the powder diffraction field is priced at well over US$ 100.00; with the added disadvantage of not having the conciseness, coherancy and clarity that a single author like Massa should allow. The Massa book on Crystal Structure Determination is highly useful. Unlike other emerging scientific and crystallographic texts, it is priced in an affordable range making it easily available to anyone involved in performing crystallography using single crystal methods.
As it is reported there is a 2nd German edition of this text in print, assuming it builds on the high quality of the first edition, it would be of major benefit to see this new edition translated into English (and other languages). This would not only benefit crystallographic teaching and education, but also people such as synthetic chemists and solid state chemists who use crystallography as a "part time" tool; and do not have access to formal crystallographic teaching courses.
Springer website: http://www.springer.de
Werner Massa's Website: http://www.chemie.uni-marburg.de/~massa/
Lachlan Cranswick
This symposium had three inter-related aims: (i) to demonstrate the use of the concept of symmetry in diverse fields, and to think of future applications (ii) to encourage inter-disciplinary dialogue between those using symmetry (iii) to identify the potential of the concept of symmetry in general education and in the public understanding of science. Most of the articles were presented at the symposium, but the editors have also included a few from other contributors which help to fulfil their aims. This is not a textbook where one chapter follows logically from the next, instead the 52 individual articles are grouped into like topics in six sections; in part 1, Shapes and fractals, Properties and regularities, Symmetries and chiralities and in part 2 Molecules and assemblies, Social culture, Artistic symmetry. Notes and references for each article are printed at the end of the article. The contents of both parts are printed in both volumes, the subject index only at the end of the second part.
There is plenty here to interest a crystallographer; articles written by acknowledged experts in their fields include that by Alan Mackay "The shape of two dimensional space", and that by Jack Dunitz, "Space filling in molecular crystals". "Crystal optics and the symmetry principle: an update" has a summary by W. Kaminsky and B.Kahr of the history of optical rotation in crystals. There are several articles on symmetry concepts in NMR Spectroscopy including "Seven-fold dynamical symmetry in solid-state NMR" by M.Levitt who has been studying the detailed geometric structure of rhodospin before and after absorbing light. Perhaps the most fundamental concepts are those described by D.Rouvray in "Symmetry in Action: the laws of Nature" which includes a summary of the work of William Hamilton and Emmy Noether"s theorem relating symmetries to conservation laws in chemistry.
Those interested in geometrical shapes will enjoy H.S.M.Coxeter"s "The rhombic triacontahedron", or M Longuet-Higgins" "On the use of symmetry for constructing polyhedral models" or the summary by I.Bergstrom and S. Frefert "On the origins of the Platonic bodies and some of their relatives" which discusses how the recent discovery of C60, which has the form of a truncated icosahedron, one of the Archimedean solids, has prompted a renewed interest in polyhedral forms. Marjorie Senechal contributes "Reflections on the Kaleidoscope", Benoit Mandelbrot "Symmetry by dilation, reduction, fractals and roughness" and Doris Schattschneider "The many faces of symmetry in the work of M.C.Escher".
The inter disciplinary nature of the books means that you may be able to persuade your University Library to buy it since there are articles of interest to historians, artists, students of foreign cultures and information technology as well as mathematicians and scientists. P.Gerdes writes on symmetry in African cultures, T Kobayashi on "What was known about the polyhedra in Ancient China and Edo Japan" where he describes early seventeenth century texts on the Platonic and Archimedean solids, but failed to look closely at the lion dogs which guard Chinese temples; some of these sculptures date from the Ming Dynasty (1368 - 1644) . While visiting the IUCr Congress in Beijing in 1993, I. Hargittai photographed the ball held in the claw of one of the lion dogs and saw that it resembled a "bucky ball", (see"The Crystallographic Tourist". page 50 "Crystallography news" No 63 December 1997.) Those who attended the IUCr Congress in Glasgow will have seen the textile exhibition organised by Annegret Haake on crystallographic themes and be interested in her description of how it started, "XX-TEX - textiles and crystallography". I also liked J.Beyers" "Symmetry concepts in quilt and fabric design", but I am not sure whether to take seriously "The songs of the double helix: symmetry and lyrical conceptualism", where Paul Hartel quotes Kepler"s "Harmonica Mundi" of 1618 describing the music of the spheres, the sun and planets which he associated with the geometrical forms of the 5 Platonic solids. Hartel thinks that music is embedded within the essential building blocks of DNA; some composers have assigned musical notes to DNA"s constituent molecules and found that members of the audience likened the resulting melodies to little known works by Bach, Brahms or Chopin! Students having difficulty in understanding the concept of symmetry in introductory crystallography courses may find it helpful to read some of the papers in the "Social Culture" and "Artistic Symmetry" sections.
I found these volumes fascinating with their interesting mix of articles showing many aspects of symmetry in our culture. However, they are expensive, costing more than many hardback textbooks, so I doubt whether University Research Groups can afford them. Try to persuade your University Library to buy them and then take them out on permanent loan.
Kate Crennell
2 July 2002
Notes:
These volumes can be purchased direct from the publisher via their web site at
http://www.portlandpress.co.uk/
Click on their 'Book catalogue' entry and then search for these volumes to find the page with a complete listing of the contents of these volumes with the titles of all the articles.
The year 2001 was the centennial of the first award of the Nobel prizes. They remain the only science prizes widely recognized by the general public and the media; for a few days each Autumn there is international and local news, sports news and science news when the achievements of the year"s Nobel Laureates are acclaimed. There are many other science prizes, how has this one captured the public attention? Have you ever wondered how the selection process works? Or whether the award of this prize changes the lives of those who receive it? István Hargittai has thought about this for some years; he has interviewed some 70 Nobel Laureates and other distinguished scientists in the fields of "chemistry", "physics", and "physiology and medicine" and distilled his findings into this book, where he explores the answers to these questions. This book is not concerned with the Prizes in economics and literature and although the title includes the word "science", this is incidental to the sociology, these people happened to be scientists; the author has sensibly refrained from trying to describe the science itself in detail, that would have made a much longer book. If you want to learn more of the science there are copious references in the Notes section which is almost 50 pages long; I expect that most BCA members will already be familiar with the science.
The first chapter explains the history of the Nobel Prizes and the annual selection process and mentions other science prizes, including the "reverse Nobel prize" known as the "Ig Nobel prize" bestowed by the Annals of Improbable Research on individuals whose "achievements cannot or should not be reproduced".
The next chapter "Nobel prizes and National Politics" explores the distribution of prizes amongst scientists of various nationalities. One problem is that the scientists themselves are more often citizens of the world than of any one country, and may not themselves have the aspirations attributed to them by others. We read (p 29) that Boris Vashtein, evaluating the life and work of Dorothy Hodgkin, noted that she "has done much for the glory of her homeland". As Hargittai remarks "This reflected more Vashtein"s way of thinking than Hodgkin"s aspirations". Scientists naturally migrate to other countries even in peace time, and in the 1930s many who later became Nobel Laureates fled Nazi Germany. The small number of prizes for Japanese scientists may also be an indication of the timidity of Western Science towards Japan. We see this also in the IUCr where an excellent Japanese bid to host the 2005 Congress was rejected in favour of one from Florence.
"Who wins Nobel prizes?" is the question posed in the third chapter. The author tries to assess the common qualities which Nobel laureates possess, and speculates on whether it may be possible to train people to become Prize winners. A later chapter on "Mentors" describes how students naturally wish to work with inspiring eminent scientists who may later win Nobel prizes; some famous examples are Frederick Sanger (winner of the Chemistry prize in 1958 and again in 1980) and his research student César Milstein who won one in medicine in 1984.
Equally interesting is the last chapter, "Who did not win?", where possible reasons are discussed as to why those who surely deserved a Nobel prize did not receive one. J.D.Bernal is perhaps the most notable crystallographer; another example is Isabella Karle, who played a significant role in putting the direct method into practice but was not awarded the Nobel prize with Herbert Hauptmann and Jerome Karle in 1985. She was given the Swedish Aminoff prize for crystallography in 1992. There are also some important newly discovered topics such as "quasi-crystals" whose discoverers have not yet received a Nobel Prize. Dan Shectmann received the Aminoff Prize for his discovery of quasi-crystals in 2000. Hargittai speculates that the Aminoff Prize may be becoming a "consolation prize" for those not awarded a Nobel prize.
The book lists the Nobel Prizes awarded in scientific fields up to 2001; it has an index to the names of the scientists but no subject index. This would have made it a much better reference tool for those who wonder which important scientific discoveries have been awarded a Nobel prize. Nevertheless, the book is very good value for money, a well produced hardback for just under £20, but the publisher saved money by binding all the photographs together in one place, I would have preferred them distributed throughout the text. If you are interested in the history and sociology of science or just wondering how to groom your students to become future Nobel prizewinners buy this book.
These notes were made up from comments received on the book review and were intended for publication in the next issue of 'Crystallography News' but lack of space prevented this.
Kate Crennell
I was pleased to receive more historical details about Fred Sanger as a 'Mentor' from John Walker; Fred fostered the research of several other Nobel prizewinners in addition to Cesar Milstein.
"Cesar Milstein did his PhD in the Department of Biochemistry in Cambridge
studying enzymes under I think Malcolm Dixon; Fred Sanger was in that
Department at the same time but Cesar was not his student. Cesar then
returned to Argentina and was encouraged by Fred to return to Cambridge
after a gap of a year or so to work on antibodies. He carried out this
work independently at the LMB in The Protein and Nucleic Acid Chemistry
Division of which Fred was the first Head after the opening of the LMB in
the early 1960s. Later, when Fred retired, Cesar succeeded him as
Divisional Head.
Without any doubt, Fred's most famous PhD student was Rodney Porter who
won the Nobel Prize for Physiology or Medicine in 1972 with Gerald Edelman
"For their discoveries concerning the chemical structure of antibodies".
Other Laureates directly associated with and influenced by Fred were Mike
Smith and myself. Mike spent a sabbatical year in Fred's Division at the
LMB from 1974-1975, working in Fred's group to determine the first
extensive DNA sequences. During this period, Mike developed his ideas with
Clyde Hutchison III about using oligonucleotides for site directed
mutagenesis, the discovery for which Mike received the Chemistry Prize in
1992. I joined Fred's Division in 1974. I worked with him and his group
on the first proteomics projects designed to understand by protein chemical
methods the meaning of the first complete DNA genomes, those in
bacteriophages phiX174 and G4 and later of the mitochondrial genome which
Fred had also sequenced. During the latter work, in the late 1970s, I
developed an interest in oxidative phosphorylation and particularly in ATP
synthase. Fred encouraged me to work on ATP synthase."
Istvan Hargittai has also sent a few more comments on 'mentoring'
"I had a lot of conversation with Cesar Milstein in addition to what
appeared in 'Candid Science: Conversations with Famous Biomedical
Scientists.' Imperial College Press, London, 2002. We spent three months
at LMB at the beginning of 2000 and we hit it off well. Cesar talked to me a
lot about Sanger's impact on him and he did call Sanger his teacher (an
inspiring teacher, he called him in the published interview). It is curious
that he never mentioned the person under whom he did do his PhD and I really
don't know why not.
As I discuss in the book, to be a mentor the person need not be a formal
supervisor, a mentor may be a teacher, may even be a person in the
literature."
Relevant Web Addresses
1. The Oxford University Press site is http://www.oup.co.uk/ search their books catalogue for the ISBN or author to find the publishers press release. You can buy the book at full list price through this site, but you may find other Internet book sellers with discount prices.
2. A site devoted to this book is http://www.roadtostockholm.com/ it has extra information, including reviews, photographs not featured in the book itself and information about the author. This site is not always obtainable, and alternate URL is: http://www.princeton.edu/~eszter/rs/
3. The Electronic Nobel Museum is at http://www.nobel.se which has full details of all the Nobel Laureates, with portraits and bibliographies. Philatelists can also access the catalogue of Swedish postage stamps now issued annually to commemmorate the Nobel Prize winners.
4. The Nobel Prize Internet Archive at http://www.nobelprizes.com has more indexes, including the "Nobel Laureates Alma Mater", an alphabetic index of all the Nobel Laureates and a "Nobel Trivia Quiz" which could be useful for those arranging a scientific social "Quiz Night".
5. The Stanford University Library has a set of useful links at:
http://www.slac.stanford.edu/library/resources/more.html#Nobel
6. The results of a "Prize Competition" in "Crystallography News" lists those Nobel Laureates who the editor thought could be described as "crystallographers" together with links to other pages giving details of their achievements http://bca.cryst.bbk.ac.uk/BCA/CNews/1997/Sep97/nobels.htm
Please send news of other relevant web sites to the BCA Education Officer preferably by email: [email protected]
The Chemical Bond in Inorganic Chemistry: The Bond Valence Model
I. David Brown, Macmaster University, Hamilton, ON, Canada
IUCr Monographs on Crystallography, Oxford University Press, 2001.
Price: £75.00 (hardback)
ISBN 0-19-8508700 x + 278 pages
Although the idea of the chemical bond is of some importance in chemistry, it has proved to be difficult to describe quantum mechanically. As Brown puts it on the first page of this excellent book, it is unlikely that, left to themselves, theoretical chemists in the twentieth century would ever have created the idea of the chemical bond had not the concept already been central to the language of structural chemistry. Thank goodness for the Victorians.
The bond valence method, which has been developed in large part by the author of this book, exploits the essential simplicity of the traditional bonding model in which an atom has a certain bonding capacity (valence) which is shared over the bonds that it forms. By drawing on the wealth of structural data which has become available as a result of the developments in crystallography over the twentieth century it has enabled an empirical relationship to be established between the length of a bond and the number if valence units that the bond contributes. It therefore forms a quantitative theory of chemical structure, which though most frequently applied to ionic solids, can be applied equally well to covalent compounds and to liquids. The beauty of the method is that it does this without recourse to lengthy calculations.
After a brief historical survey given in Chapter 1, Chapters 2 and 3 examine the theoretical basis of the bond valence method. It is possible to calculate the Madelung or electrostatic field of an ionic crystal, and the collection of all the lines of field joining two charges forms the bond between them. The strength of the bond is characterised by the electrostatic flux. This procedure clearly requires extensive calculation, but fortunately the bond fluxes are generally the same as experimental bond valences (Sij), derived from crystallographically determined interatomic distances (Rij) using Brown's famous equation:
Chapter 4 examines the concept of cation and anion bonding strength and the valence matching principle, which states that the most stable compounds are formed between cation and anions with similar bonding strengths. Chemists will recognise the similarity of this principle to Pearson's hard and soft acid and base principle, and the relationship between the two is discussed. The nice thing about bonding strengths is that they easily calculated and they explain a lot. For example in PO43- the valence of the central atom is 5, that of oxygen is 2. Each P-O bond must have a valence of 5/4=1.25 to satisfy the phosphorus, leaving the oxygen 0.75 valence units (v.u.) for external bonding - for example to a counter-cation. Generally oxygen forms four bonds; one of these is to the phosphorus, and so that each external bond will be worth 0.25 v.u, the anion bonding strength of phosphate. Phosphate is a stronger anion than sulfate, which has a strength of 0.17 v.u. In these few lines lies the explanation for the differences between phosphate and sulfate chemistry. The idea is developed in the following chapter into a discussion of solubilities and the formation of secondary solvation shells in aqueous solution. There is a short, but interesting, section on silicates. Magmas which are rich in magnesium (strength 0.33) tend to crystallise as Mg2SiO4 because SiO44- also has a strength of 0.33. Magmas rich in weaker sodium (strength 0.17) tend to form Na2Si2O5 because the strength of the Si2O52- anion is 0.17. The book is full of 'nice' illustrations like this.
Chapter 6 examines the influence of anion-anion repulsion and cation-to-anion bonding strength as factors which determine the co-ordination numbers of cations. A discussion of hydrogen bonds, that is the structural chemistry of the H+ cation, is given in Chapter 7, and their somewhat anomalous properties shown, as a development of the material presented in the previous chapter, to be a result of anion-anion repulsions. Madelung fields have been calculated explicitly only for symmetrical structures, and Chapter 8 tackles the problem of distorted structures, and how a local polarisation model can be used to interpret them. For example, cations such as Tl+ can form stable compounds with anions with varying bonding strengths, and this can be related to the polarisation of its lone pair of electrons. The oddly distorted structures of d0 transition metal complex can be addressed with a similar model. Chapter 9 brings the section of the book devoted to fundamental chemical principles to a close with a review of the properties of bonds, such as bond lengths and angles, force constants and their response to temperature.
The next section of the book concentrates of the general theme of the structures of inorganic solids. There is a need to satisfy both chemical and symmetry constraints when compounds form crystals, and the first chapter of this section (10) gives a brief introduction to space group theory. In addition to the two methods described above, bond valences may also be calculated from a bonding graph in the absence of experimental information from the requirement that the sum of the valences of the bonds made to a particular atom must equal the atomic valence of that atom. Thus, in the case of NaCl, where each cation and anion forms six bonds, each bond must be equivalent to 0.17 valence units. Where symmetry is lower non-equivalent bonds have different valences, and so this constraint is usually not enough to form a tractable set of simultaneous equations. In these cases a valence is considered to be positive in the direction anion to cation, and a further equations are added using constraint that that the sum around a closed loop must equal zero. The application of these theoretical bond valences to modelling crystal structures will be clear, and the approaches for predicting topologies are described in Chapter 11. The material covered ranges more widely than the immediate application of the bond valence method, and (for example) methods based on simulating annealing for crystal structure prediction are also covered. Structures in which experimentally determined bond valences differ from the theoretical valences just described are termed as being strained, and Chapter 12 examines this topic in detail.
The remainder of the book reviews applications of the bond valence method in crystallography, chemistry, physics, mineralogy and biology. A well known crystallographic application is in the assignment of oxidation states, and the calculation of the occupancies of Fe2+ and Fe3+ in the octahedral and tetrahedral metal sites in Fe3O4 is given as a specific example. The final chapter attempts to place the bond valence method into the context of other bonding theories.
Although there are several excellent reviews on the bond valence method in the literature there has long been a need for a dedicated monograph on the subject. This book will appeal to appeal to anyone interested in the structure of solids, including crystallographers, structural chemists and materials scientists. Professor Brown has written a highly readable book about a theory that, though it has long found application in inorganic crystal chemistry, deserves to be used more widely. One needs only a pencil and a calculator to use it, and having read the book, readers will be inspired to apply this simple predictive theory to their own work.
Simon Parsons
Nucleic Acid Structure and Recognition, From the double helix to the ribosome
Stephen Neidle, The Institute of Cancer Research (University of London)
Oxford University Press, 2002
Price: £29.50 (Paperback )
ISBN 0-19-850635-X, xi + 187pp
Skipping through Brenda Maddox's new book on Rosalind Franklin is thought-provoking on the history of DNA structure determination. A discarded title for 'The Double Helix' was apparently 'Base Pairs', according to Brenda Maddox a punning self-accusation by Jim Watson that he and Francis Crick had, without her knowledge, made use of Rosalind Franklin's experimental fibre diffraction patterns.
If the fiftieth anniversary of the Watson-Crick model, looming in early
2003, provokes a new wave of interest in nucleic acid structure, alongside
the renewed interest in these old controversies, Stephen Neidle's excellent
new introductory textbook will prove to be very timely, and provides a calm,
balanced and objective study of the major advances. Practising scientists
are increasingly too busy for textbook writing, but nothing can replace the
perspective that someone of Steve's experience brings to this subject. The
book's predecessor, 'DNA Structure and Recognition' was published in 1994,
and for the last seven years has been my main introductory recommendation
for students of nucleic acid structure for its clarity, brevity and balance.
The new book incorporates all the major advances since then, and has the
added bonus of a website
(www.oup.com/na-structure) and
has free access even if you don't buy the book.
Chapter One describes methods for studying nucleic acid structure, with a short discussion of the X-ray method, and a quick look at n.m.r., molecular modelling methods and databases. Chapter Two is perhaps the most immediately useful for a newcomer, a guide through the complexities of the nomenclature used to describe nucleic acid structure and conformations (slide, roll, twist, pucker, buckle, tilt, and the rest.....), which are very confusing at first. Chapter Three goes back to the original technique used for studying DNA structure, fibre diffraction, and compares these average results with the details available using single crystals. It is striking that the originaltriplex, and Holliday junction DNA (see picture), all of these structures having resisted years of attempts to demonstrate their crystallographic existence. DNA has the reputation of being difficult to crystallise, because, unlike proteins, it is never globular and always has the negative charge of the phosphates which must be neutralised with cations, but (perhaps so as not to frighten newcomers?) this book makes no direct mention of these problems. It is at this point that the use of the pdb files on the website is particularly encouraged, because unlike the double helix, readers won't be familiar with these recent exotica. (Note - if you try this, the right hand mouse button is the key to unlocking some very pretty and useful ways of viewing the molecules with Chime. Happy viewing!). Chapter Five is an introduction to DNA interactions with small molecules - DNA crystals typically contain at least 50% water, much of which is ordered into well-studied hydration patterns. Drug and cation binding perturb this; a study of these interactions often suggesting modes of DNA-protein interaction, the subject of Chapter Seven.
Chapter Six, though, is an important area which the predecessor book did not cover (hence the change in title) - the RNA Structural World. The compact tertiary structures of RNA are the closest analogues in the nucleic acid field to the folding of globular proteins. We are fortunate that Venki Ramakrishnan has very kindly accepted the BCA's invitation to give the Max Perutz Memorial Lecture at the Spring Meeting in April 2003, when we hope to be treated to a guided tour of the amazing complexity of the ribosome. Meanwhile, this book includes a short and readable description, and the webpage gives quick access to the ribosome coordinate files for an awesome molecular experience (and, yes, you can try this at home, even, I thought the ribosome would crash my PC but it didn't!) - 'the ribosomal RNA framework is likely to be largely invariant throughout the living world', as the penultimate sentence of this excellent short summary puts it And with that mind-boggling thought, let me congratulate Steve on making this subject so accessible to such a potentially wide audience.
Christine Cardin
Outline of Crystallography for Biologists
David Blow, Imperial College, London
Oxford University Press, 2002
Price: £25.00 (paperback)
ISBN 0 19 8510519, 236pp
This compact and informative book begins with a quotation from Max Perutz to whom the book is dedicated: ' The X-ray study of proteins is sometimes regarded as an abstruse subject comprehensible only to specialists, but the basic ideas underlying our work are so simple that some physicists find them boring'
A major change in the area of X-ray crystallography has been the invasion of the field by biologists and biochemists who are prepared to have a go at tackling 'their' protein without much formal training. The daily correspondence over the various e-mail bulletin boards provides a lively record of hundreds of intrepid amateurs in laboratories round the world who follow computational recipes and travel far down the sometimes tortuous paths of structure determination. This have-a-go approach should certainly be encouraged and is undoubtedly contributing to the continued exponential growth of protein structures now available - fast approaching the 20,000 mark.
This book is therefore a very timely contribution as it provides newcomers to the field of protein crystallography with a concise outline of the background physics together with an overview of the practical aspects of protein structure determination by crystallography. David Blow is one of the grand masters of protein crystallography and has made many major contributions to the field ; notably in the original development of the theory of molecular replacement and in pioneering work on the structure determination of many key enzymes. I was intrigued to see how someone with such profound insight of the subject would tackle the job of explaining the theory and practise of this arcane art in less than 250 pages in a palatable form suitable for biologists.
The chosen format is to divide the book into two equal halves in which the first more theoretical part discusses crystal symmetry and the physics of diffraction while the second part tackles the more practical steps covering all stages from data collection to structure refinement. It is also claimed that the text is suitable for those with a minimal background in maths. To this end grey-shaded boxes are scattered through the text segregating out algebraic formulae and theoretical explanations. This seems like an excellent idea. To capture the full flavour of the book I read all the grey boxes. In some chapters the approach works well and the thread of the narrative text is maintained. In the chapters on Waves and Diffraction the boxes dominate and this makes for a more patchy read. The second half of the book has excellent chapters on isomorphous replacement, anomalous scattering and molecular replacement. In all chapters in this section Blow makes good use of well selected historical and recent papers to provide examples of the procedures being described. In such an all encompassing book it is impossible to cover all definitions and there are a few places in the book which may puzzle the true novice where terms like s (I), c* and 'phasing power' are introduced in the text without having been defined. Such pedantries should not however spoil enjoyment of the book and I can warmly recommend it to novices and experts alike.
With excitement still high about structural genomics, the future of protein crystallography over the next decade is assured and is set to drift steadily further away from the realms of physics into arms of the biologists. Indeed no crystallography laboratory can exist nowadays without strong biological projects and the editors should perhaps consider a sister volume 'Molecular Biology for Crystallographers and Bored Physicists'
Malcolm D. Walkinshaw