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Software Packages

The TCM Group is responsible for several large academic software packages. Casino, Castep and Onetep were all created in TCM, and the others listed below were created outside of TCM but currently have TCM members as active authors or maintainers.



CASINO is a computer program system for performing quantum Monte Carlo (QMC) electronic structure calculations. It is capable of calculating incredibly accurate solutions to the Schrödinger equation of quantum mechanics for realistic systems built from atoms. This helps us understand and predict the nature of the Universe.

CASINO Website


CASTEP is a leading code for calculating the properties of materials from first principles. Using density functional theory, it can simulate a wide range of properties of materials proprieties including energetics, structure at the atomic level, vibrational properties, electronic response properties etc. In particular it has a wide range of spectroscopic features that link directly to experiment, such as infra-red and Raman spectroscopies, NMR, and core level spectra.

CASTEP website


OptaDOS is a code for calculating optical, core-level excitation spectra along with full, partial and joint electronic density of states (DOS). The code is written by Andrew Morris and Chris Pickard at the University of Cambridge and Rebecca Nicholls and Jonathan Yates at Oxford University. OptaDOS is written in Fortran 95 and may be run in parallel using MPI. At OptaDOS interfaces with CASTEP and ONETEP output files, although it is extendible to perform calculations on any set of band eigenvalues and their derivatives generated by any electronic structure code.

OptaDOS web site


ONETEP (Order-N Electronic Total Energy Package) is a linear-scaling code for quantum-mechanical calculations based on density-functional theory.

ONETEP website


Siesta (Spanish Initiative for Electronic Simulations with Thousands of Atoms) is another linear-scaling DFT code with a global user-base.

Siesta website

Pseudopotential generators

The TCM group has a long history in designing electron-atom pseudopotentials. Libraries are available for QMC and CASTEP supports on-the-fly pseudopotential generation.

Recently, the group has developed particle-particle pseudopotentials. Software to generate these is available for cold atom gases in 3D and 2D.


Dr Moller is one of the maintainers of DiagHam a GPLed set of C++ classes for exact diagonalization of various quantum systems. The project is based at the ENS, Paris.

Michael Rutter's Software

The Group's Computer Officer, Michael Rutter, has written several utilities which have been distributed outside of TCM. Notable amongst these are bmp2eps, a converter from pnm/bmp/gif/jpeg/png to eps/ps/pdf/png which treats JPEGs losslessly and tries to minimise output size, and check2xsf which can perform many manipulations on Castep input and output files including building supercells and extracting wavefunctions and densities for visualisation.

These and more are collected together on a separate page of Michael Rutter's programs.