First-principle study on polarizability and hyperpolarizability of a transition metal cluster, [Mo2S3(C6H11)3(CO)6]·N(C2H3)4

Abstract

We reported the first-principle study of linear and nonlinear optical polarizability of a di-nuclear transition metal cluster, [Mo$_{2}$S$_{3}$(CO)$_{6}$(C$_{6}$H$_{11}$)$_{3}$]·N(C$_{2}$H$_{3}$)$_{4}$, by using finite-field method. The calculations were performed at an HF/Lanl2dz level. The spatial average value of the first hyperpolarizability along z direction was very large, β$_{z} = 13.8 × 10 ^{-30}$ esu, indicating the potential applications of this cluster for IR nonlinear optical processes. Our results showed that the charge transfer inside the metal core cluster, [Mo$_{2}$S$_{3}$(CO)$_{6}$], played an important role in nonlinear optical response while the joint effect of metal core and organic ligands (C$_{6}$H$_{11}$)$_{3}$ also contributed to nonlinear optical polarizability. In addition, the organic ionic group, [N(C$_{2}$H$_{3}$)$_{4}$]$^{+}$, situated in z direction enhanced the β$_{z}$ value. The study may help us to understand the nonlinear optical nature of the transition metal clusters and provided an example to show the computational efficiency of finite-field method in the first-principle theoretical study of the complex system containing transition-metal element.