1. Institute of Natural and Mathematical Sciences; Massey University; 1/5 University Avenue Albany Auckland 0632 New Zealand
2. Centre for Theoretical Chemistry and Physics, NZIAS; Massey University; Oaklands Road Albany Auckland 0632 New Zealand
3. Department of Physical and Theoretical Chemistry; Faculty of Natural Sciences; Comenius University; Ilkovičova 6 Bratislava Slovakia
4. Centre for Advanced Study; Norwegian Academy of Science and Letters; Drammensveien 78 NO-0271 Oslo Norway