1. Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, D-85748 Garching, Germany
2. ISIS Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K.
3. Scientific Computing Department, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K.