[1] Karlsruhe Inst Technol, CFN, D-76049 Karlsruhe, Germany
[2] Karlsruhe Inst Technol, Inst Phys Chem, D-76049 Karlsruhe, Germany
[3] Virginia Tech, Dept Chem, Blacksburg, VA 24061 USA
[4] ETH Honggerberg, Phys Chem Lab, CH-8093 Zurich, Switzerland
[5] Ruhr Univ Bochum, Lehrstuhl Theoret Chem, D-44780 Bochum, Germany
[6] Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England