1. Dept. Materials Science and Engineering (DMSE) and Dept. Chemistry Indian Institute of Technology, Delhi, Hauz Khas, New Delhi-110016, India
2. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
3. Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
4. Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA