1. Department of Chemistry, and LMCC-Mathematical Modeling and Computational Science Center, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium
2. School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
3. Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Jackson State University, Jackson, Mississippi 39217-0510, United States