1. Department of Physics and Astronomy and the Center for Simulational Physics, The University of Georgia, Athens, Georgia 30602, USA
2. Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
3. Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
4. Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
5. Department of Physics, Penn State University, Berks Campus, Reading, Pennsylvania 19610, USA