含碱金属分子簇体系的结构和NLO性质

Structures and NLO Properties of Molecular Clusters with Alkali Metal Atom

采用MP2方法优化得到Li(HF)n(n=2～4)体系的三个环型结构.使用高水平的从头算方法MP2/6-311++G(3df,3pd)计算了它们的偶极矩μ0、极化率α0和一阶超极化率β0.得出了大的一阶超极化率的变化规律,并揭示出额外电子是引起大一阶超极化率的主要原因.

By using ab initio calculation, three structures with all real frequencies were obtained for the Li （HF） n （ n = 1-4 ） clusters. The dipole moments （μ）, polarizabilities （α0） and the first hyperpolarizabilities （β0） of Li（HF） n （ n = 2-4） were investigated at MP2/6-311 ＋ ＋ G（3df,3pd） level. The large first hyperpo-larizabilities（β0） （53710×10^-33-113270× 10^-33 esu） were found. It is revealed that the contributions of Li polarized to α0 and β0 values are dominantive.