1. Centre for Theoretical and Computational Molecular Science Australian Institute for Bioengineering and Nanotechnology The University of Queensland Brisbane Queensland 4072 Australia
2. State Key Laboratory of Precision Spectroscopy School of Physics and Material Science East China Normal University Shanghai 200062 P. R. China
3. School of Mathematics and Physics The University of Queensland Brisbane Queensland 4072 Australia
4. School of Physics The University of Sydney Sydney New South Wales 2006 Australia
5. School of Chemistry and Molecular Biosciences The University of Queensland Brisbane Queensland 4072 Australia