1. Department of Pharmaceutical Sciences, University of California, Irvine, California 92697, United States
2. Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
3. School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
4. Department of Chemistry, University of California, Irvine, California 92697, United States