Welcome to the Webpage of Symmetry Projection, Symmetry Adaptation and Irreducible Representations of Finite Groups.
MATLAB scripts are available for calculating symmetry adapted spherical harmonics (SYMPRJS) and plane waves (SYMPWS) for double space groups, using functions for calculating irreducible representations of the group of the k-vector.
The scripts for calculating irreducible representations of finite groups are also available as a stand alone MATLAB program (Irrep).
SYMPRJS/SYMPWS is largely based on the QCPE (Quantum Chemistry Program Exchange) FORTRAN program QCPE259 (SYMPRJ/SYMPW), giving symmetry adapted orbitals for single space groups.
Irrep is an extension of the QCPE FORTRAN program QCPE163 (IRREP). The extension being that Irrep will also handle irreducible representations with no non-degenerate eigenvalues.
These MATLAB scripts are available for free through an e-mail request to: