Affiliation: | 1. Department of Chemistry, Georgetown University, 37th & O streets, NW, Washington, DC 20057 (USA), Fax: (+1)?202‐687‐6209;2. Computational Chemistry Group, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6320, Gaithersburg, Maryland 20899‐6320 (USA) |