1. Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
2. Department of Chemistry, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 69978, Israel
3. Department of Physics, Nagoya University, Nagoya 464-8602, Japan