1. Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
2. University College London, Kathleen Lonsdale Materials Chemistry, Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, U.K.
3. Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K.
4. Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, U.K.