1. School of Chemistry, Trinity College Dublin, Dublin 2, Ireland, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Dublin, Ireland, Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010, Australia, Department of Chemistry, University College Cork, Cork, Ireland, and Institute of Chemical Physics, University of Latvia, Raina Boulevard 19, LV-1586 Riga, Latvia