1. Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana 47803
2. Department of Chemistry and Physics, Indiana State University, Terre Haute, Indiana 47809
3. Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, United States
4. Programa de Ingeniería Molecular, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, México, D.F. 07730, México
5. Schlumberger-Doll Research, Cambridge, Massachusetts 02139, United States