Second-order nonlinear optical effects in C59Si and C58Si2

Using quantum chemical molecular dynamics geometry optimization calculations of the second-order optical susceptibilities for C59Si and C58Si2 molecules were done. We have found that the substitution by two silicon atoms favors larger second-order optical susceptibility comparing with that one for the one-atom substitution. For the C58Si2 molecule, the indicatrice of the photoinduced second-order susceptibility is more isotropic comparing with the one-atom substitution. The results obtained for the second-order nonlinear optical susceptibilities using computer simulations for C59Si and C58Si2 molecules are in good agreement with the experimental photoinduced optical second harmonic generation data.