This project was funded under the HECToR Distributed Computational Science and Engineering (CSE) Service operated by NAG Ltd. HECToR - A Research Councils UK High End Computing Service - is the UK's national supercomputing service, managed by EPSRC on behalf of the participating Research Councils. Its mission is to support capability science and engineering in UK academia. The HECToR supercomputers are managed by UoE HPCx Ltd and the CSE Support Service is provided by NAG Ltd. http://www.hector.ac.uk. I would like to thank Dr. P. Ridley for the patience and help with the proposal and report, and Prof. A. T. Paxton, Dr. A. Lozovoi, T. Sheppard and Dr. A. Elena for the help and discussions.