1. Department of Chemistry Columbia University 10027 New York NY USA
2. Department of Chemistry & Biochemistry University of Maryland 8051 Regents Drive, College Park 20742 Maryland MD USA
3. Department of Chemistry Texas A&M University 3255 TAMU, 580 Ross St 77843 College Station TX USA
4. IBM Research—Almaden 650 Harry Rd. 95120 San Jose CA USA