1. School of Earth, Atmospheric & Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL, U.K.
2. School of Chemistry, University of Birmingham, Birmingham B15 2TT, U.K.
3. Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent ST4 7QB, U.K.
4. Diamond Light Source Ltd., Didcot, Oxfordshire OX11 0DE, U.K.
5. Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352
6. School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, U.K.
7. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720