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1028 SOFTWARE REVIEWS smoother when 64 Mbytes are avail- as colour and transparency of the iso- References able. surface. Additionally, the unit-cell box, Grahn, H. (1999). GLVIEW3.6, http:// transparent cell walls and cell grid lines www.snafu.de/~hg/. Documentation: Documentation is may be added to the VRML ®le. provided in the form of HTML docu- Sun Microsystems (1999). Sun Micro- systems, http://www.sun.com. ments. There is also an on-line version of this documentation available at http:// Method of solution: After reading the www.nirim.go.jp/~weber/JAVA/JSV/jsv. electron density data (or any other html. volumetric data), the polygonization of the isosurface is performed by means of Availability: JSV1.07 can be down- a so-called marching cubes algorithm. Software Reviews loaded from http://www.nirim.go.jp/ The number of generated polygons can be very high (>50000). JMap3D allows a Software for review in this section should be sent ~weber/JAVA/JSV/jsv.html. direct to the Software-Review Editor, whose address coarser grid of the input data to be used, appears on the inside front cover of the journal. References thus reducing the polygon count as well as the size of the VRML ®le. When Grahn, H. (1999). GLVIEW3.6, http:// J. Appl. Cryst. (1999). 32, 1028±1029 displayed with Gouraud shading, www.snafu.de/~hg/. generally no loss of quality is observed Izumi, F. (1999). FAT-RIETAN: Rietveld as a result of choosing a subset of the Re®nement Software. Home page of ± Visual Structure full data set. In addition to that, JMap3D Fujio Izumi, http://www.nirim.go.jp/ Information System has a built-in feature for performing a ~izumi. polygon count reduction, based on a so- Kraus, W. & Nolze, G. (1996). J. Appl. Available from: Crystal Impact, called progressive meshes algorithm. Cryst. 29, 301. K. Brandenburg & M. Berndt GbR, Depending on the isosurface topology, Materials Data Inc. (1999). MICRO Postfach 1251, D-53002 Bonn, the polygon count can thus be reduced POWD, http://www.materialsdata. Germany (tel. +49 228 73 5825; to about 10% of the original number com. e-mail: [email protected]; without seriously affecting the truthfull- Sun Microsystems (1999). Sun Micro- WWW: http://www.crystalimpact.com). ness of the isosurface. This algorithm systems, http://www.sun.com. Current version: 2.1b. Price: Single basically removes many small and license E998.00 or US $1100.00. nearly coplanar triangles by trans- WILLIAM T. P ENNINGTON Additional users: E498.00 or forming them into fewer but larger US $550.00. Site licence (per Department of Chemistry triangles. department): E1998.00 or Clemson University US $2200.00. In all cases there Clemson Program speci®cation: The program is is a 50% academic discount. written in JavaTM using the JDK1.2TM (Java Development Kit) from Sun DIAMOND ± Visual Microsystems (Sun Microsystems, Information System is a Windows-based J. Appl. Cryst. (1999). 32, 1028 1999). It therefore can be executed graphics program (Windows 95 or under Windows, as well as under Linux, higher required) for drawing crystal which is gaining popularity in the scien- structures. Installation of the program is JMap3D ± VRML isosurface ti®c community. simple and straightforward. Although no generator written manual is provided in either hard-copy or electronic form (a minor Software environment: For executing drawback), a tutorial is available that is S. WEBER JMap3D a Java virtual machine, such quite helpful in getting started. An online as the Java interpreter, which is manual is also available, and provides NIRIM, Namiki 1-1, Tsukuba, Ibaraki included in JDK1.2, must be installed on ready answers to most questions that 305, Japan your computer. A VRML viewer from the arise. Additional support is provided Java3D±VRML working group is (Received 25 June 1999; through the Internet (http://www.crysta- accepted 2 July 1999 ) included in the distribution. This, limpact.com/diamond/support.htm) or however, requires Java3D to be through direct electronic correspon- installed on your computer in addition to dence ([email protected]). A The crystallographic problem: This JDK1.2. This viewer is mainly provided database of 40 structures pro- program was written speci®cally for the for Linux users, since other VRML vides numerous examples of the cap- purpose of rendering electron density viewers running under Linux may not be abilities of the program. data into three-dimensional isosurfaces, readily available. For Windows users, DIAMOND features a split-screen utilizing the VRML2.0 format (virtual the stand-alone VRML viewer format with the left portion of the screen reality modelling language). The user's GLVIEW3.6 (Grahn, 1999) is recom- serving as the structure window and the electron density data have to be pro- mended, which is far better than any right portion being a `data sheet' con- vided in a simple ASCII format or in VRML browser plug-in tested by the taining useful crystallographic informa- binary format. The ®le format is descri- author. tion such as and space bed in the documentation included in the group, dimensions, atomic coor- distribution. JMap3D can create up to Availability: A public version of dinates, vibrational displacement para- ®ve isosurfaces, whereby for each iso- JMap3D can be downloaded from http:// meters and selected geometric surface a different electron-density ®le www.nirim.go.jp/~weber/JAVA/JMAP3D parameters. The relative sizes of these may be speci®ed. In this way it is pos- /JMAP3D.html. two windows can be readily adjusted sible to show, for example, Fourier data through mouse repositioning of a `split- together with difference Fourier data or ter'. Numerous options for structure MEM data. For each isosurface an iso- Keywords: JMap3D; VRML; 3D elec- construction and manipulation are density value can be speci®ed, as well tron-density maps. available. On-screen buttons, supple-

# 1999 International Union of Journal of Applied Crystallography Printed in Great Britain ± all rights reserved ISSN 0021-8898 # 1999 SOFTWARE REVIEWS 1029 mented by balloon help messages, selection feature is especially useful, as suf®cient depth to be used alone. Alas, contain intuitive symbols to indicate their whole supramolecular features can be my hopes were quickly dashed, and I function, and more advanced operations highlighted. was forced to conclude that this book can be accomplished through a variety The wide variety of functions available fails on two levels, both at the level of of pull-down menus. The structure and in DIAMOND make it a powerful tool for scienti®c detail and at the level of basic data-sheet windows are coupled, and both teaching and research. Its modest communication. selections or adjustments made in one price and substantial academic discount My disappointment began on p. 9 of are immediately re¯ected in the other. warrant its consideration for any crys- chapter 1, where the authors de®ne Data can be input manually, but the tallographic teaching laboratory, and the potential energy `as the work done by program also reads a variety of standard planned release of a `student' edition will the electron in moving from in®nity (zero formats. Expansion of this list, for make it even more attractive. energy) to r'. The equation appears, example to all commercially available however, as packages that are typically used, would WILLIAM T. P ENNINGTON be a welcome addition, but availability of r a free format read allows for adequate Department of Chemistry V Fdr ; Clemson University j jˆj j interaction with most. Structure devel- Z0 opment is accomplished through func- Clemson tions to expand molecular fragments, ®ll SC 29634-1905 instead of with a lower limit of and, unit cells, display multiple unit cells, USA with the absolute signs removed1 in the complete user-de®ned coordination next lines, there are inconsistencies in spheres and delete nonbonded atoms the signs of the resultant work and force or whole fragments. terms. Misprints or misconceptions? It is Structure representation can be tog- dif®cult to say, as both abound gled between a stick diagram, stick and throughout the text. Bad editing and ball, space-®lling spheres and thermal Book Reviews poor proofreading are evident in the ellipsoids. Presentation can be made in misplacement or omission of de®nite either a draft-quality ¯at mode or a more Works intended for notice in this column should be and inde®nite articles, mispellings and realistic render mode. Rotation and sent direct to the Book-Review Editor, whose address different spellings for the same word in appears on the inside front cover of the journal. As far the same line (`micelle' and `miscelle', orientation of the structure are easily as practicable, books will be reviewed in a country accomplished with menu buttons for `X/ different from that of publication. etc.) and downright confusion of lan- Y rotation', `Z rotation', `center of rotation guage. What, for example, is one to de®nition', and `shift' for structure repo- J. Appl. Cryst. (1999). 32, 1029 make of this sentence on p. 104? `The sitioning within the window. Analysis of metallic radii are de®ned in the same structural detail is facilitated by a `zoom' way as ionic except for no dif- function. On the very low-end Pentium Materials crystal chemistry.ByRELVA ference between atoms as cation and system used for this review (120 MHz), C. BUCHANAN and TAEUN PARK. Pp. vii + anion.', or the particularly egregious rotation function on all but the stick 462. New York: Marcel Dekker, Inc., error on p. 132 where, in a section diagram was rather slow and jerky; 1998. Price US $175. ISBN 0-8247- headed `3. Block (sic) Equation', a however, dramatic improvement would 9798-1 paragraph begins `The base of band be expected with even moderate system theory in solid state physics is Block enhancement. This book is `intended primarily for theory which descibes (sic) the wave DIAMOND was speci®cally written for engineers, advanced undergraduates function of an electron in a periodic inorganic structures and its features for and graduate students in materials potential. In crystal, the position ...'. displaying these in polyhedral format engineering, materials science and After these experiences, I admit that I are a strength of the program. Various allied scienti®c disciplines'. It contains did not go carefully through the polyhedron formats are available, and four chapters, entitled: Fundamentals of remaining mathematical equations, the de®nition and design of these, Atoms, Molecules and Solids (130 pp.); either in the chapter or in the appen- based on the central atom, is straight- Fundamentals of Crystallography dices. forward and easy. The de®nition and (94 pp.); Crystal Structures (84 pp.) and I had higher hopes for chapter 2, inclusion of `dummy atoms' provides a Structure Changes in Crystals (112 pp.). Fundamentals of Crystallography, but particularly useful tool for many of these Two appendices, special functions in here too problems quickly emerged. The types of structures. Combined with quantum mechanics and quantum ®rst page of the chapter discusses the structure-development features mechanical background for the simple stacking directions of points to form a described above, nice quality packing expression of the lattice energy of ionic lattice and introduces the concept of the diagrams of even very complicated crystals, a bibliography and an index , but then a statement appears inorganic structures can be produced make up the rest of the work. that when the `atomic arrangement is with a minimum of input. Once con- When I began to leaf through the ®rst taken into account, the stacking direc- structed, the structure can be examined two chapters, with their large numbers tion is no longer arbitrary' as if one could from various directions through a pull- of detailed subtopics, I had high hopes not always select a triclinic unit cell as down menu for this purpose. that I was looking at a new genre of long as it contains the asymmetric unit. Although written for inorganic struc- texts for teaching this subject. Usually, Confusion between the metric of a unit tures, DIAMOND is equally useful for texts on crystal chemistry treat atomic cell and the dimensional requirements viewing molecular compounds or even theory and bonding at the level of imposed by symmetry is present proteins, and is especially good for freshman chemistry and crystallography throughout the chapter. Thus the cir- those involving signi®cant inter- receives only a cursory overview. The cular `lattice provides the basis for molecular interactions, such as hydro- primary emphasis in most texts is on crystal symmetry' where later the gen bonding. Connectivities can be crystal structures and the crystal- authors state that the of the de®ned for a variety of criteria, in order lography section needs to be supple- unit cell is determined by the symmetry. to distinguish between types of interac- mented with a second text. It seemed They also state that `Any solid exists in tions present in a structure. A fragment that this text covered these topics in one of three states: single-crystal, poly-