1. Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
2. Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
3. Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles (ULB), CP 160/09, 50 Ave. F.D. Roosevelt, 1050 Brussels, Belgium
4. Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
5. National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
6. University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom