1. Department of Physics, University of Crete, Heraklion-Crete, Greece.
2. Department of Chemistry, University of Crete, Heraklion-Crete, Greece.
3. Institute of Electronic Structure and Laser, Foundation for Research and Technology–Hellas, 71110 Heraklion-Crete, Greece.
4. Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, GA 30322, USA.
5. School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.