Specification and system requirements

Overview

Crystallographica is essentially a visualisation program, consisting of a series of tools for setting and displaying a multitude of properties of a crystal structure. Some of these tools are highly visual in nature: the program incorporates a structure drawing package, reciprocal lattice display and powder pattern simulation. A set of dialogs allow not only crystal properties to be set, but also provide quick and easy methods for viewing crystal properties.

All these features are shared by the Lite and Full versions of Crystallographica. The Full version adds a unique crystallographic scripting language which allows a whole new level of flexiblity and power to the program. This language is fully integrated with the other tools, and may be used for anything from calculating simple properties to creating stunning animations.

Details of Crystallographica's tools are given below, together with system requirements (basically any PC running Windows 3.1 or better). To get more of a flavour, take a look at some screen shots, or best of all, download a demo.

Specification

Graphical tools

• Crystal structure drawing
  Integrated crystal structure drawing package allows a number of views of the same structure or else comparision of different structures. Plots can be examined using the mouse and keyboard to rotate and zoom the image, or controlled precisely from the Interpreter.
• Vrml export
  VRML files can be exported, showing crystal structure and including anisotropic displacement ellipsoids, polyhedra and crystal planes.
• Reciprocal lattice display
  Integrated viewer allows the reciprocal lattice to be displayed in a variety of styles including unweighted, weighted and Argand. Viewing direction may be synchronised with other such windows and with structure display.
• Powder simulation
  Powerful, flexible X-ray and neutron powder diffraction pattern simulation including Rietveld-style control over peak shape and width. Simulated pattern may be compared with experimental data in the graphing tool. Profile and peak data may be exported to file. Scripting language includes utilities for combining plots to form multi-phase patterns or residuals.
• (x,y) graphing
  Flexible graphing tool with a number of features designed for use with diffraction data. Plots may be created from powder simulations, data held in interpreter arrays or read from files in a variety of commonly-used formats.
• Dialog boxes
  A set of simple and easy-to-use dialogs provides a powerful user interface to access atom properties, contents of asymmetric unit, cell parameters, bond lists, crystal symmetry (via space group or list of generators), radiation, reflection lists, powder simulation and VRML options.

Crystallographic scripting language (not Lite version)

• Pascal interpreter
  supporting variables, arrays, records, sets, functions and procedures. Extensions to core Pascal include exponential operator, dynamic sizing of arrays and enhanced string handling. The interpreter may be used interactively or called to run scripts contained in text files.
• Function library
  A library of several hundred crystallographic routines covering atom properties, bonding, cell parameters, symmetry, radiation, reflections, powder simulation, crystal structure drawing and graph plotting.
  User-scripted routines are easily integrated, so that the system can be customised.

Crystallographic utilities

• Databases
  A set of databases holding information on X-ray and neutron scattering factors including dispersion corrections, absorption factors, X-ray wavelengths, bonding radii, elemental properties and space group symmetry.
• CIF and shelxl support
  Import / export of Crystallographic Information Files and Shelxl .ins and .res files.

Help, support and upgrades

• Comprehensive help
  Comprehensive context-sensitive on-line help including tutorial guide and Pascal primer.
• Technical support
  Free, unlimited technical support via email.
• Upgrades
  Free upgrades available from our Web site for the lifetime of the 16-bit program. Current users have seen up to eight major improvements!

System requirements

Crystallographica will run on a machine with the following minimum specification:

• IBM compatible 386 or higher PC
• at least 4 Mb of RAM.
• 10 Mb free disk space.
• MS Windows 3.1x/95/98/NT/ME/2000/XP