Mechanical Properties of Ultra Small Nanoparticles Using First Principles Calculations *L. Pizzagalli (Institut PPRIME), R. Polisetty (Institut PPRIME), J. Durinck (Institut PPRIME), S. Brochard (Institut PPRIME), J. Furstoss (Institut PPRIME), J. Godet (Institut PPRIME), M. Ramirez (Universidad de Chile), A. Varas (Universidad de Chile), F. Valencia (Universidad Católica del Maule)