The first hyperpolarizabilities of four squaric acid homologues: squaric acid, 1, 2-dithiosquaric acid, 1, 2-diselenosquaric acid and 1,2-ditellurosquaric acid have been calculated using ab initio and DFT methods. The...The first hyperpolarizabilities of four squaric acid homologues: squaric acid, 1, 2-dithiosquaric acid, 1, 2-diselenosquaric acid and 1,2-ditellurosquaric acid have been calculated using ab initio and DFT methods. The effects of equilibrium geometries. basis set and electron correlation on the first hyperpolarizabilities of these molecules were investigated. The frequency dispersion effect and solvent effect, which are essential to get reliable outputs in comparison to the experimental results, have also been explored. On the basis of these investigations, it is worthy to point out that the heavy atom effect takes effect for these squaric acid homologues.展开更多
文摘The first hyperpolarizabilities of four squaric acid homologues: squaric acid, 1, 2-dithiosquaric acid, 1, 2-diselenosquaric acid and 1,2-ditellurosquaric acid have been calculated using ab initio and DFT methods. The effects of equilibrium geometries. basis set and electron correlation on the first hyperpolarizabilities of these molecules were investigated. The frequency dispersion effect and solvent effect, which are essential to get reliable outputs in comparison to the experimental results, have also been explored. On the basis of these investigations, it is worthy to point out that the heavy atom effect takes effect for these squaric acid homologues.