Software Fayre

Throughout the IUCr Glasgow Congress, a Software Fayre was held to allow software authors and users to interact with the various freely available packages useful to Crystallographers. Thanks to the generosity of SGI and Compaq and the help of the organising committee, attendees had access to 3 Silicon Graphics O2s, 2 Compaq PCs running Redhat Linux and 5 Compaq PCs running Window95; as well as an overhead computer projector for demonstrating software to larger crowds.

Small-molecule single-crystal software

J. Gallagher demonstrated the ORTEX for Windows single crystal suite (based around Shelx for solution and refinement); S. Hall and B. Skelton, the XTAL single crystal solution and refinement suite running on UNIX and Windows; P. Mallinson and T. Richter, the 'Project XD' Charge Density Software; D. Watkin and R. Cooper the new GUI based CRYSTALS refinement suite for Windows; L. Farrugia the WinGX for Windows suite (based around Shelxs, Sir and Dirdif for solution and Shelxl for refinement). R. Spagna demonstrated the combination of using Sir and CAOS (Crystal Analysis Operating System) to solve (Sir for direct methods, CAOS for Patterson methods) and CAOS for refining structures; M. Dusek, the JANA98 program (UNIX and PC) for refinement of ordinary and modulated structures; P. and G. Beurskens the Patterson methods and difference direct methods based DIRDIF structure solution package (UNIX and PC). R. de Gelder showed how easy it is to compile and install the the direct methods CRUNCH structure solution package under UNIX and Linux for handling difficult structures. F. Pavelcik demonstrated the Patterson methods based XFPA structure solution program (UNIX and PC) and T. Spek the Platon/'System S' single crystal suite (UNIX/Linux) (Shelxs, Sir, Dirdif and Crunch for structure solution, Shelxl for refinement and powerful Platon tools).

Powder diffraction

Demonstrations included: R. Shirley on the CRYSFIRE powder indexing suite who successfully indexed some Protein powder diffraction data provided by Bob von Dreele; A. Le Bail on solving structures from powder diffraction data using the Monte Carlo based methods incorporated into the ESPOIR software; and J. Rodriguez-Carvajal showed the latest foolproof Rietveld friendly plug-in, the 'GFOURIER' Fourier Map generation and display software.

Protein/macromolecular crystallography

On the protein side, software demonstrations included P. Williams on the XtalView program for UNIX (fitting electron density maps and solving structures by MIR and MAD software); I. Uzon applying Shelxpro/Shelxl for refinement of protein structures (with the possibility of using XtalView to view the maps); M. Szebenyi, the MacCHESS Software/ GUI for processing protein crystallographic data using DPS programs, mosflm, and some CCP4 programs; and a demonstration of MICE (Molecular Sciences and Interaction Environments). B. von Dreele also showed GSAS in action which is now also used powder diffraction refinement of Protein structures, with maps and structure linking into the Swiss-PDB Viewer.

Databases, structure manipulation, diffuse scattering and educational software

A. Hewat used one of the SGI O2s to demonstrate the web-based ICSD (Inorganic Crystal Structure Database) and a Linux machine was applied for a DISCUS diffuse scattering/ crystallographic teaching demonstration by T. Proffen and R. Neder. PowderCell for Windows and Cryscon for Windows were shown as effective tools for dealing with structure transformations, including classical phase transformations. Most of the above mentioned software is available for download via the internet for anyone to try out. The powder diffraction and single crystal software is also mirrored (where possible) on the CCP14 website and its mirrors (http://www.ccp14.ac.uk). Thus there is no excuse not to try some of these tools and check their suitability to assist in high quality crystallographic analysis.

Web addresses where expanded descriptions of all programs described and demonstrated can be found on the BCA website (http://gordon.cryst.bbk.ac.uk/ BCA/index.html) from which this article was taken.