(BCA (British Crystallographic Association) SPRING MEETING 2000, 3rd to 5th April, 2000, Heriot-Watt University, Edinburgh. (Abstracts viewable at: http://www.isis.rl.ac.uk/BCA2000/)) Tuesday 4th April 2000, 9.00   CCG workshop: Software demonstrations on recent developments in software for chemical crystallography (Chaired by Simon Parsons of Edinburgh University) 09.00-09.30 Paul Buerskens   DIRDIF: Routine structure solution using your chemical knowledge 09.30-10.00 Chris Gilmore   maXus 10.00-10.30 George Sheldrick   Direct Methods for Larger Structures 10.30-11.00 ---- Coffee ----   11.00-11.30 David Watkin   CRYSTALS: The Next Generation 11.30-12.00 Ton Spek   The Multiple Faces of Platon 12.00-12.30 Lachlan Cranswick   Freely available software tools for chemical crystallography A possibly inaccurate/biased(?) summary of what went on in the session. (Corrections Accepted. It should be noted that tutorials on most of the mentioned/related software are available from the CCP14 site. Photos on this page can be freely copied if wanted) Paul Buerskens (with Bob Gould operating the PC Computer) gave a live demonstration of Dirdif 2000 - structure solution using Patterson methods, fragment searching methods and difference direct methods. The DDFLEX intra-fragment flexibility option was also demonstrated (Dirdif 2000 with DDFLEX not yet released - please be patient). From memory, George Sheldrick mentioned it was easy to see that DOS/Windows was being used for the demonstration machine as the system had to be rebooted half way through the demonstration. (was actually a crash in the "microemacs" editor that caused this - not DIRDIF). Chris Gilmore gave a live demonstration of the commercial Maxus for UNIX software. This links to a variety of structure solving and building options. Automatic structure solution and refinement as well as overlapping 3D structure plots with 3D Fourier maps were some of the features explored. George Sheldrick gave a talk about Shelxd for structure solution of large structures (not yet released - enable "please be patient mode"). Elaboration was made on the use of "random omitting" of 30% of the atoms as part of an effective search algorithm; as well as the nuances of solving of large structures using available algorithmic options. David Watkin gave a talk and live demonstration about the philosophy and functionality behind the latest Crystals for Windows. With the emphasis on also allowing the chemist to perform high quality structure solution and refinement. (Though with the institute's expert crystallographer being accessible to sort out any specialised problems prompted by warnings from Crystals). Ton Spek gave a set of examples and live demos on Platon/System S for: validation, as well as some of the crystallographic tools it contains. Ton also demonstrated the NQA (no questions asked) option to automatically solve and refine a structure. System S links to Shelx97/86, Sir97, Dirdif 99.2 and Crunch for solving structures and EXOR, Sir99, Dirdif 99.2 and Crunch for auto-building of structures. The Squeeze option was discussed for handling nasty solvent effects. This resulted in a discussion on the ethics of using squeeze modified data for publications. A summary from Sandy Blake was he did not see a problem as long the submitting author(s) described honestly what they did and why they did it. It was mentioned this option would be best put inside structure refinement refinement software. One thing missed from the formal demonstration, was the use of Platon to do very quick and user-friendly searching of the Cambridge database for cells and related structures via spawning Quest in the background at the click of a button. Lachlan Cranswick (CCP14 Secretary - Hurrah!) talked about various freely available software programs relevant for Chemical Crystallography with the emphasis on the benefits of making use of the available genetic diversity of the available software. This included running through the available indexing, solving, refinement, structure quality checking, photorealistic rendoring, animation of structures, and briefly on powder diffraction options. Mention was made of the not yet released (enable "please be patient mode") SXGRAPH in WinGX (by Louis Farrugia - primarily for GUI control of Shelx files) in the context of its ability to import/clean fragments then pass it easily into Dirdif for fragment searching. The latest Sir2000 was also mentioned with comments on large structures it had already solved (structures with "202 non-H atoms" to "1,910 non-H atoms (with 374 waters))". The aim is for Sir2000 to handle greater than 2000 atoms in the asymmetric unit. (Not yet released - most likely after ECM 2000 in Nancy - please be patient). Information on easy download, installation and running of the Crunch and Shake-n-Bake software was also explored. A live demonstration of using the Crysfire / Chekcell combination for indexing of powder data (when those single crystals are too small) was given. As well as suggesting the Sirware EXPO software as a first call for trying to solve structures from powder data when a cell and spacegroup has been obtained. Concerns were raised by George Sheldrick over Crystalographic suites that make it easy for users to avoid seeing the warning messages. This was discussed by the audience.

Image (Flash not used so as not to distract the presenters)	Description
	BCA Biological Group Prize (photo taken by Kate Crennell) BCA Biological Group Prize (photo taken by Kate Crennell)

Bob Gould preparing for Dirdif demonstration Simon Parsons introducing the Chemical Crystallography Software Session

Simon Parsons introducing the Chemical Crystallography Software Session Paul Buerskens presenting Dirdif demonstration

Paul Buerskens presenting Dirdif demonstration Paul Buerskens presenting Dirdif demonstration

Bob Gould running the Dirdif demonstration PC Paul Buerskens presenting Dirdif demonstration

Chris Gilmore presenting a Maxus demonstration Chris Gilmore presenting a Maxus demonstration

Chris Gilmore presenting a Maxus demonstration George Sheldrick presenting information on ShelxD

George Sheldrick presenting information on ShelxD George Sheldrick presenting information on ShelxD

Simon Parsons and intermission David Watkin starting his presentation.

David Watkin presenting a Crystals 2000 demonstration David Watkin presenting a Crystals 2000 demonstration

David Watkin presenting a Crystals 2000 demonstration David Watkin presenting a Crystals 2000 demonstration. Ton making sure Linux Laptop is working prior to platon demonstration.

David Watkin presenting a Crystals 2000 demonstration David Watkin presenting a Crystals 2000 demonstration

David Watkin answering questions. Simon Parsons also visible. David Watkin answering questions. Simon Parsons also visible.

Ton Spek presenting Platon/Pluton/System S demonstration Ton Spek presenting Platon/Pluton/System S demonstration

Ton Spek presenting Platon/Pluton/System S demonstration Ton Spek presenting Platon/Pluton/System S demonstration

Link to notes for Lachlan Cranswick's (CCP14 Secretary) talk on: "Freely available software tools for chemical crystallography"

(Lachlan Cranswick was too busy yapping away to take a digital photo of himself!)