1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
2. Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
3. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
4. Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States