1. The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323,
United States
2. Arkema Inc., 900 First Avenue, King of Prussia, Pennsylvania
19406, United States
3. DuPont Experimental Station, Wilmington, Delaware 19880-0308,
United States
4. Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104,
United States