1. Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
2. Department of Physics, Yeshiva University, New York, New York 10016, United States
3. University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
4. University of Illinois, Urbana, Illinois 61801, United States
5. Department of Chemistry, Middle East Technical University, Ankara, Turkey 06531
6. Hungkuang University, Taichung, Taiwan 433
7. Shell Oil Company, Houston, Texas 77082, United States