1. Energy Sciences and Technology Department, Brookhaven National Laboratory, Upton, New York 11973-5000, Department of Materials Science and Engineering, Stony Brook University, Stony Brook, New York 11794-2275, Institut für Anorganische Chemie und Analytische Chemie, Universität Mainz, Staudingerweg 9, D-55099 Mainz, Germany, and SFA, Advanced Technology Division, Largo, Maryland 20774