1. Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, Center for Computational Sciences, University of Kentucky, Lexington, Kentucky 40506-0045, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, P.O. Box 1527, 71110 Heraklio, Crete, Greece, and Department of Chemistry, University of Crete, P.O. Box 1470, Heraklio, Crete, Greece 71409