Author/Authors :
Silva-Filhoa، نويسنده , , D.A. and deMeloa، نويسنده , , C.P. and Kirtmanb، نويسنده , , B. and Totoc، نويسنده , , T.T. and Totoc، نويسنده , , J.، نويسنده ,
Abstract :
We have completed a quantum chemistry study of the nonlinear polarizabilities of polyenic chains containing a single solitonic defect (S). We show the differences in geometries predicted by the AM1, ab initio 6-31G (ai) and MP2 methods when a negatively charged S− defect is present. For S chains of increasing sizes we compare the evolution of γxxxx, the longitudinal component of the second hyperpolarizability, calculated using different hamiltonian approximations.