There are 3 programs in this file:

CRYSTALS-32

CRYSTALS is a widely distributed package for single crystal structure analysis, including routines for data reduction, Fourier refinement, least-squares refinement (including absolute configuration, twinning, disorder, non-crystallographic symmetry, eigenvalue filtering and robust-resistant weighting), structure modelling and modification, analysis of structure, analysis of residuals, preparation of text and cif tables, structure visualisation and hardcopy colour graphics. Because all these features are incorporated in a single package, the user can move easily from calculations to visualisation to revised calculations, and as such it is a powerful environment for dealing with both routine and non-routine structures.

Now, after 3 years of work involving collaboration with programmers in America, France, Scotland and Switzerland, we are approaching the Beta release of the native WINDOWS 95/NT versions of CRYSTALS.

Every output statement in CRYSTALS has been reviewed and revised to meet modern requirements. Removing some of the old text was a rather melancholy exercise, since in their time the messages proudly announced new crystallographic innovations. Many of the items on users 'wish-lists' have at last been incorporated. The visualisation module (CAMERON) was upgraded by Louis Ferrugia to run in a proper Window, and has now been back-ported into CRYSTALS.

A massive re-organisation of the internal data base and extension of the structure factor expressions by Ludger Schroeder now enables the program to handle models composed of both conventional anisotropic atoms and diffuse electron density distributed over non-atomic shapes.

A completely new graphical menu system has been developed by Richard Cooper, Markus Neuburger and Ludwig Macko. This sits above the crystallographic routines, and enables a script-writer to control the degree of interaction between the program and its user. Scripts exist for many routine operations, and to control an undergraduate demonstration of crystal structure analysis and Patterson methods.

Interfaces permit the input of reflections in Sheldrick HKLF, native CAD4 (MACH3) and Denzo/Scalepack formats. Bob Gould's program SXTOCRY converts a basic SHELX.INS file to CRYSTALS format, and Bruce Foxman's CSDTOCRY converts a CSd data file to CRYSTALS format. For direct methods, CRYSTALS communicates easily with SHELXS and SIR92. The CRYSTALS cif is compatible with CHECKCIF and Ton Specks PLATON, and the graphical output from CAMERON is in Postscript or encapsulated Postscript.

Lachlan Cranswick (at CCP14) has put a lot of effort into setting up a CRYSTALS web page, which will shortly be available to guide users through installation and initial use. Keep your eye on http://www/ccp14/co/uk/

Because of the deep seated changes which have been made to the code, CRYSTALS-32 is being released in phases. Phase one will consist of the crystallographic code, the graphical editor and the command line script system, and as such is more-or-less a replacement for the DOS version of CRYSTALS. This release will only be available to experienced CRYSTALS users. Those interested in trying it out should contact us by E-mail at [email protected].

David Watkin
University of Oxford

Oscail - Windows based software
for single crystal and powder diffraction

Patrick McArdle, National University of Ireland, Galway.

This windows based system provides the following facilities:

All of the components of the system are controlled by Oscail and Windows help is provided for all of the programs. The excellent text editor PFE is incorporated into the system. Most operations are just mouse clicks.

A brief summary of some of the systems features -

Absen - The Space Group Determination program is useful from an educational point of view as it lists the special reflections in a way which makes clear the number of reflections on which each condition depends.

Ortex - The visualisation and structure editing program can display and rotate up to 2,500 thermal ellipsoids in mono or stereo. The stereo can be red-green 3D or conventional. Hard copy output may be written in a range of formats (including HPGL and EPS) but may also be printed directly on the PC's printer. Direct picture import is possible into all versions of WORD.

This system provided the first Windows version of Raster 3D the Unix program developed by Ethan Merritt. Programs are also provided which can be used to make rendered movies.

It is often wise to check if a single crystal structure is applicable to a bulk sample. The powder software can convert a .HKL file to a pattern with "powder profiles." These patterns are often indistinguishable from experimental ones.

This software uses SHELXS and SHELXL which are provided by Professor Sheldrick. These programs should only be used by registered SHELX users.

A web tutorial which includes a worked example and ten data sets suitable for use in advanced undergraduate practicals is also available.

The software is provided free to academic users and can be downloaded from
http://www.nuiGalway.ie/cryst/software.htm.

WinGX for Single-Crystal Small Molecule Crystallography

The processing of a small molecule single-crystal X-ray or neutron structure, from the diffraction data through structure-solution and refinement to preparation of publication material, is nowadays a well established and usually reasonably automated procedure. There are several excellent commercial software packages such as SHELXTL and TeXsan which provide all the necessary programs to undertake this procedure, but these packages are often quite expensive and usually tied to the sale of specific diffractometer hardware.

Throughout the last three decades a great deal of superb crystallographic software which is in the public domain, or which is at least freely available, has been written. Such programs include the structure-solution packages SHELXS, DIRDIF and SIR and refinement programs such as SHELXL. In general, programs written by different authors use different file syntax for common information such as unit cell parameters, atomic coordinates etc. To ensure that the whole structural determination procedure is as automated and simple as possible, it is desirable to spend little time and effort in the data transfer between different programs. The WinGX suite is a coherent collection of programs running under MS-Windows, in which the best available public domain software has been included. The transfer of information between different programs is handled automatically, and only rarely will it be necessary for the user to manually edit files for this purpose. Most programs have graphical user interfaces for the selection of options.

The WinGX suite includes industry standards such as SHELXS, DIRDIF, SIR92, SHELXL93 and ORTEP. Several absorption correction methods are available e.g. analytical, Gaussian grid, psi-scans, multi-scan, DIFABS. Contoured electron-density Fourier maps may be drawn and examined in cases of disorder. A number of programs for the geometrical analysis of results are provided, including PLATON, PLUTON, PARST and THMA11. A range of graphics programs are available for structure visualisation, while publication- and presentation-quality graphical hard-copy may also be obtained using the ray-tracing programs POV-Ray and Raster3D. Publication output via the CIF format is fully supported and extensive checking of CIF-syntax and IUCr data validation is possible. There also interfaces to external graphics programs such as RasMol and SCHAKAL and newer programs like SHELXL97 and SIR97. A large number of utility routines have been written to automate transfer of data from other systems, edit model files, display data etc and there are also many user-modifiable interfaces to favourite external programs.

Literature references to all the programs mentioned above in the WinGX package are given in the program documentation, which is provided as HTML files for hypertext viewing and MS-Word/PostScript files for hard-copy.

The program itself and other associated programs are available from the following web-site : http://www.chem.gla.ac.uk/~louis/software


Louis Farrugia
University of Glasgow

Page last updated 12 Mar 1999

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