1. Department of Physics, Seton Hall University, South Orange, New Jersey 07079, USA
2. Department of Chemistry and Biochemistry, Seton Hall University Center for Computational Research, South Orange, New Jersey 07079, USA
3. Material Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
4. ULVAC, Inc., Susono, Shizuoka 410-1231, Japan
5. IBM Research, San Jose, California 95120, USA
6. IBM T. J. Watson Research Center, Yorktown Heights, New York 10598, USA