Xtal_GX consists of a subset of the Xtal3.5 crystallographic computing package. It is released freely to the crystallographic community in the form of binary executables for numerous platforms running Xwindows (or DOS). Rights to the source code have been retained by the Xtal coordinators.
Calculations performed by Xtal_GX are:

  • ADDATM enter atom coords in non-CIF format
  • BONDLA determine molecular geometry data
  • BUNYIP search for additional symmetry
  • CIFIO read, write and validate CIF data
  • CREDUC search for alternate cell settings
  • LSQPL least squares lines and planes data
  • NEWMAN generate Newman plots of molecule
  • ORTEP ellipsoid molecule/cell plots
  • PIG display & manipulate structure
  • PLOTX prepare PostScript or HPGL plots
  • PREVUE display and modify text of plots
  • STARTX create initial archive file

Xtal_GX was designed primarily to read and write crystal structure information in the form of CIFs (Crystallographic Information Files). It can be used to validate CIFs against the IUCr CIF dictionary, prior to submission to IUCr journals such as Acta Crystallographica.

In addition to parsing CIFs, Xtal_GX also extracts symmetry and structural information for display manipulation and plotting purposes. Molecules can be viewed and oriented for subsequent thermal ellipsoid (ORTEP) plotting in postscript format. Additional routines assess the structure for unrecognised symmetry elements in the structure and these symmetry elements can also be graphically represented.

Xtal_GX is controlled by commands in a control file. Extensive description of the available commands are described in the 30 page postscript doccumentation (only for version 2), available in two formats:

Xtal_GX Package

The Xtal_GX Package consists of the main executable (machine specific) accompanied by a driver script, several essential auxilliary files containing CIF definitions etc and lastly a series of test CIFs and control files.

The additional README contains more extensive installation instructions than are documented here.

It will be necessary for you to choose one of the following executables to suit your computing environment :

version 3

version 2

The following auxilliary files are essential. Their have been changes to cifdic, symmap and cifmap between versions 2 and 3.

  • xerror Error message database
  • symmap Crystallographic symmetry mapping file
  • cifdic The IUCr CIF dictionary
  • cifmap CIF input parser
  • cifreq CIF output parser

The following files are essential, but platform specific.

  • GX The driver script for UNIX systems
  • GX.COM The driver script for VMS systems
  • GX.BAT The driver script for DOS PCs

The following test files are recommended.

You would also be severely disadvantaged if you did not get the postscript format documentation outlined above. Should you not have access to a postscript printer, then you should really check out the GhostScript home page. GhostScript could be useful for all your postscript printing and viewing needs. Failing that contact xtal@crystal.uwa.edu.au and a copy of the Xtal_GX documentation can be sent to you by airmail.

DOS Xtal_GX Package

Currently one MS DOS package is available iether as the basic executable indicated above, or as a self extracting archive, with dos readme and installation instructions .

To Install this DOS version copy the files from Xtal_GX to a DOS directory, say "GX" and then run the self extracting executable "gxexe.exe" to unpack the necessary executables and auxiliary files.

Last update: Aug 14 1997.