1. Computer-Chemie-Centrum; Friedrich-Alexander-Universität Erlangen-Nürnberg; Nägelsbachstrasse 25 91052 Erlangen Germany
2. Department of Chemistry and Institute of Structural and Molecular Biology; University College London; London WC1E 6BT UK
3. School of Pharmacy and Biomedical Sciences; University of Portsmouth; Portsmouth PO1 2DT UK
4. UNICAEN, CERMN; UPRES EA 4258, FR CNRS 3038 INC3M -; Normandie Univ.; Boulevard Becquerel 14032 CAEN Cedex France