1. Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica del Litoral, ESPOL, Km 30.5 vía Perimetral, Campus Gustavo Galindo; Guayaquil Ecuador
2. Centro de Química, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado 21827; Caracas 1020-A Venezuela
3. Theoretical Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4; 9747 AG Groningen The Netherlands
4. Laboratory for Laser Energetics, University of Rochester, 250 E. River Road; Rochester New York 14623 USA