1. Center for Atomic‐Scale Materials Design, Department of Physics, Technical University of Denmark, DK‐2800 Kgs. Lyngby (Denmark), Fax: (+45) 4593‐2399
2. Department of Materials Science and Engineering, Northwestern University, Evanston, Ilinois 60208 (USA)
3. Dpto. de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E‐28049 Madrid (Spain)
4. Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (USA)
5. Department of Chemical Engineering, Stanford, California, 94305‐5025 (USA)
6. SLAC National Accelerator Laboratory, Stanford, California, 94025‐7015 (USA), Department of Chemical Engineering, Stanford, California, 94305‐5025 (USA)