1. Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
2. Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee 37996, United States
3. Bremen Center for Computational Materials Science, Universität Bremen, Bremen 28359, Germany
4. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
5. Department of Physics, Boston University, Boston, Massachusetts 02215, United States
6. Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States
7. Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States