1. Department of Chemistry, Minnesota Supercomputing Institute and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
2. Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
3. Department of Chemistry, Pritzker School of Molecular Engineering, James Franck Institute, Chicago Center for Theoretical Chemistry, The University of Chicago, 5735 S Ellis Avenue, Chicago, Illinois 60637, United States
4. Underwriters Laboratories Inc., 333 Pfingsten Road, Northbrook, Illinois 60026, United States