Construction and diagonalization of the Hamiltonian matrix is therate-limiting step in most low-energy electron -- molecule collisioncalculations. Tennyson (J Phys B, 29 (1996) 1817) implemented a novel algorithmfor Hamiltonian construction which took advantage of the structure of thewavefunction in such calculations. This algorithm is re-engineered to make useof modern computer architectures and the use of appropriate diagonalizers isconsidered. Test calculations demonstrate that significant speed-ups can begained using multiple CPUs. This opens the way to calculations which considerhigher collision energies, larger molecules and / or more target states. Themethodology, which is implemented as part of the UK molecular R-matrix codes(UKRMol and UKRMol+) can also be used for studies of bound molecular Rydbergstates, photoionisation and positron-molecule collisions.
展开▼
