1. Jülich Centre for Neutron Science at MLZ, Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85748 Garching, Germany
2. Jülich Centre for Neutron Science (JCNS-1/IBI-8: Neutron Scattering and Biological Matter), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
3. Institut Laue-Langevin (ILL), B.P. 156, F-38042 Grenoble, Cedex 9, France
4. Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States