1. Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
2. Department of Materials Science and Engineering and Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110016, India
3. Materials Physics and Applications Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States