Université de Bordeaux, Institut des Sciences Moléculaires, 351 Cours de la Libération, 33405 Talence, France.
J Chem Phys. 2012 Jan 14;136(2):024506. doi: 10.1063/1.3675848.
Hyper-Rayleigh scattering (HRS) experiments and quantum chemical calculations are combined to investigate the second-order nonlinear optical responses of a series of reference molecules, namely, carbon tetrachloride, chloroform, trichloroacetonitrile, acetonitrile, and dichloromethane. The multipolar decomposition of the first hyperpolarizability tensor through the use of the spherical harmonics formalism is employed to highlight the impact of the symmetry of the molecular scatterers on their nonlinear optical responses. It is demonstrated that HRS is a technique of choice to probe the molecular symmetry of the compounds. Coupled-cluster calculations performed at the coupled-cluster level with singles, doubles, and perturbative triples in combination with highly extended basis sets and including environment effects by using the polarizable continuum model qualitatively reproduce the molecular first hyperpolarizabilities and depolarization ratios of the molecular scatterers.
超拉曼散射（HRS）实验与量子化学计算相结合，研究了一系列参考分子的二阶非线性光学响应，这些分子分别为四氯化碳、氯仿、三氯乙腈、乙腈和二氯甲烷。采用球谐函数形式对第一超极化率张量进行多极分解，突出了分子散射体对称性对其非线性光学响应的影响。结果表明，HRS 是探测化合物分子对称性的一种选择。采用含单电子、双电子和微扰三电子的耦合簇方法，结合高度扩展的基组，并通过极化连续模型考虑环境效应，在耦合簇水平上进行的耦合簇计算，定性地再现了分子散射体的分子第一超极化率和去偏振比。
