1. Centre for Science at Extreme Conditions, Erskine Williamson Building, The King’s Buildings, The University of Edinburgh, Mayfield Road, Edinburgh, EH9 3JZ, United Kingdom, School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, United Kingdom, Institut Laue-Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France, and ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, United Kingdom