1. Department of Chemistry and Interdisciplinary Nanoscience Center, University of Aarhus, Langelandsgade 140, DK-8000 Aarhus, Denmark; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan; Department of Inorganic Chemistry, Stockholm University, SE-10691 Stockholm, Sweden; and Grundfos A/S, Poul Due Jensens Vej 7, DK-8850 Bjerringbro, Denmark