CASTEP

What is CASTEP?

CASTEP is a software package which uses density functional theory to provide a good atomic-level description of all manner of materials and molecules. CASTEP can give information about total energies, forces and stresses on an atomic system, as well as calculating optimum geometries, band structures, optical spectra, phonon spectra and much more. It can also perform molecular dynamics simulations.

Tell me more about how CASTEP uses density functional theory.

Where did CASTEP come from?

CASTEP was originally created by Prof. M.C. Payne and subsequently developed by various UK academics, primarily from the TCM group in Cambridge. For various technical reasons, it was felt in 1999 that the original code was in need of a total re-design and re-write, and so the CASTEP Development Group was created to do just that, using modern coding styles and Fortran90. CASTEP is marketed commercially by Accelrys, along with Materials Studio, their graphical frontend for MS Windows. In the United Kingdom there is an academic distribution, maintained by UKCP.

The key features of this new plane-wave code were that it was to be:

Designed and specified in advance
Portable
Parallelised
Clear, modular structure
Have the same or better feature set as the old F77 code
Have the same or better performance as the old F77 code

and the first completed version of the new F90 code was ready in 2001.

The aim of the project was to produce a code which would not only perform density functional calculations quickly and reliably, but which would be easy to maintain and to extend. As a result of this, many new features have been added, such as linear response calculations, that would have been very complex to add to the old code.

Following discussions with Accelrys it was agreed that the new code would become the new version of CASTEP, and would include equivalent - or better - functionality and performance to CASTEP 4.2. The finished code was eventually released 2 years later in Materials Studio 2.1.5, and has entirely superseded the old CASTEP. Materials Studio provides a graphical frontend for setting up CASTEP input files, as well as visualising and analysing the output.

Tell me more about CASTEP's development.

What is the CASTEP Development Group (CDG)?

The CDG is a small group of UK academics working in the field of density functional theory and electronic structure calculations. The group was first formed in 1999 to write a plane-wave density functional code from the ground up. Its members were drawn from the research groups in the UKCP consortium, and all had extensive experience with the original CASTEP code.

The current CDG members are Matt Segall, Matt Probert, Chris Pickard, Phil Hasnip, Stewart Clark, Keith Refson, Jonathan Yates and Mike Payne.

Tell me more about the CDG.

Where can I learn more about using CASTEP?

There are a number of tutorials written within the CDG to guide you through the process of using CASTEP for some real-world calculations. There is also extensive on-line help within the Materials Studio product, and some useful case studies can be found on the Accelrys CASTEP website.

Show me more CASTEP links.

What platforms is CASTEP available on?

Whilst Materials Studio is only available on MS Windows running on PC-compatible hardware, CASTEP itself is highly portable. It is officially supported on PCs with MS Windows or Linux and has also been ported to cygwin, Mac OS, SGI, Sun, IBM and various Cray architectures. The code can be run in both serial and MPI-parallel computers. CASTEP has also been successfully ported to many other workstations and supercomputing platforms.

How can I get CASTEP?

Copies of Materials Studio and CASTEP can be purchased from Accelrys. If you are a UK academic then you qualify for the free academic version of CASTEP, which is available via UKCP from CCPForge.

If you have any comments about these pages, you can email Matt Probert as mijp1 at york.ac.uk