1. Department of Chemistry, University of Oslo, Postboks 1033 Blindern, 0315 Oslo, Norway
2. Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, Villigen 5232, Switzerland
3. Institut Laue-Langevin, 71 Av. des Martyrs, 38000 Grenoble, France
4. Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, Postboks 1033 Blindern, 0315 Oslo, Norway