1. Unidade de Ciências
Químicas e Radiofarmacêuticas, IST/ITN,
Instituto Superior Técnico, Universidade Técnica de Lisboa, 2686-953 Sacavém, Portugal
2. Department
of Chemistry, Supercomputing Institute and Chemical Theory
Center, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
3. Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States