1. Institute for Chemistry and Biochemistry/Crystallography, Free University of Berlin, Fabeckstr. 36a, 14195 Berlin, Germany, DESY/HASYLAB, Notkestr 85, 22603 Hamburg, Germany, Institute for Inorganic Chemistry, Georg August Universität, Tammannstr. 4, 37077 Göttingen, Germany, Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark, c/o DESY/HASYLAB, Notkestr 85, 22603 Hamburg, Germany, and Mineralogisch-Petrologisches Insitut, Universität Hamburg, Grindelallee 48, 20146...