1. Department of Electrical and Systems Engineering, Washington University in St. Louis 1 , St. Louis, Missouri 63130, USA
2. Department of Physics and Center for Complex Network Research, Northeastern University 2 , Boston, Massachusetts 02115, USA
3. Institute of Chemistry, Department of Physical Chemistry, University of Campinas 3 , Campinas, SP 13083-970, Brazil
4. Department of Chemistry, Saint Louis University 4 , St. Louis, Missouri 63103, USA