1. Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi−Hiroshima 739-8527, Japan
2. Department of Physics, Chemistry and Biology, Linköping University, S-581 83 Linköping, Sweden
3. Department of Quantum Chemistry, Uppsala University, S-751 20 Uppsala, Sweden
4. Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600