1. Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científicas (IEM-CSIC), Serrano 121, 28006 Madrid, Spain
2. Department of Scientific Research, The Metropolitan Museum of Art, 1000 Fifth Avenue, New York, New York 10028, United States
3. Department of Chemistry, City College of the City University of New York, 160 Convent Avenue, New York, New York 10031, United States