1. IBM Research UK, Hartree Centre, Daresbury WA4 4AD, United Kingdom
2. STFC Daresbury Laboratories, Daresbury WA4 4AD, United Kingdom
3. National Physical Laboratory, Hampton Road, Teddington, United Kingdom
4. GSK Medicines Research Centre, Stevenage SG1 2NY, United Kingdom
5. IBM T. J. Watson Research Center, Yorktown Heights, New York 10598, USA
6. Maxwell Centre, University of Cambridge, Cambridge CB3 0HE, United Kingdom