1. São Carlos Institute of Physics, University of São Paulo, P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
2. Modeling and Molecular Simulation Group, São Paulo State University, 17030-360 Bauru, SP, Brazil
3. CCAF, PPGCEM/CDTec, Federal University of Pelotas, CEP 96010-610 Pelotas, Rio Grande do Sul, Brazil