1. Department of Chemistry, University of Durham, South Road, Durham, UK DH1 3LE
2. Chemical Crystallography, Department of Chemistry, University of Durham, South Road, Durham, UK DH1 3LE
3. GlaxoSmithKline, R&D Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K.