1. Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
2. CNR-IOM, Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
3. CNRS, Institut de Biologie Structurale, 71 Avenue des Martyrs, 38044 Grenoble, France
4. European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38043 Grenoble, France
5. Jülich Centre for Neutron Science and Institute of Biological Information Processing (JCNS-1/IBI-8), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
6. Department of Physics, University of Rome La Sapienza, Piazzale Aldo Moro 2, 00185 Rome, Italy