1. Departamento de Química Inorgánica, Facultad de Ciencias
Químicas, Universidad Complutense, Madrid 28040, Spain
2. Lujan Neutron Scattering Center, Los Alamos National Laboratory, MS H805, Los Alamos, New Mexico, 87545,
United States
3. Institut Laue-Langevin, 6 rue Jules Horowitz, 38042
Grenoble Cedex 9, France
4. Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210-1185, United States