1. School of Computer Science; University of Nottingham; Jubilee Campus; Wollaton Road Nottingham NG8 1BB United Kingdom
2. Institut für Informatik III; Universität Bonn; Römerstraße 164 53117 Bonn Germany
3. School of Chemistry; University of Nottingham; University Park Nottingham NG7 2RD United Kingdom
4. GlaxoSmithKline; Medicines Research Centre; Gunnels Wood Road Stevenage, Hertfordshire SG1 2NY United Kingdom
5. Department of Computer Science and Engineering Washington University in St. Louis; One Brookings Drive CB 1045 St. Louis, MO 63130 USA