计算分子二阶超极化率的基组选择  

A study of Basis set for calculating the Second hyperpolarizabilities γ of molecules

作　　者：刘柳斜[1] 丁涪江[1] 

机构地区：[1]四川师范大学化学系,成都610061

出　　处：《原子与分子物理学报》2005年第1期143-148,共6页Journal of Atomic and Molecular Physics

基　　金：四川省教育厅课题 ( 2 0 0 3A0 87)资助项目

摘　　要：设计和使用了扩展的 6 - 3 1G ,D95 ,ANO ,aug cc pVDZ基组以及Hypol基组 ,用各种相关能级别的方法SCF ,MP2 ,MP3 ,MP4D ,MP4DQ ,MP4SDQ ,MP4 ,CCSD ,CCSD(T) ,计算了H2 O ,CO ,HF ,H2 ,N2 等分子的二阶超极化率。分别以 4 aug cc pVTZ基组在不同方法下的二阶超极化率结果 ,和CCSD(T) / 4 aug cc pVTZ水平上的结果作为标准 ,求得各水平计算相对应的平均相对偏差。结果发现 :MP2 /aug cc pVDZ +是计算二阶超极化率最优的水平。综合讨论认为 :可在MP2 /aug cc pVDZ +水平上计算分子的二阶超极化率 ,其结果是可靠的。而且如果同时要计算分子极化率和一阶超极化率 。The second hyperpolarizabilities (γ) of several molecules H_2O,CO,HF,H_2 and N_2 have been calculated at the expanded basis sets: 6-31G+,D95+,ANO+,aug-cc-pVDZ+, and Hypol,4-aug-cc-pVTZ basis sets by Finite-Field method (FF) method in the context of electron correlation corrected molecular energies. Because the Hartree-Fock limits can be obtained at the 4-aug-cc-pVTZ basis set, this basis set is good estimates for choosing the suitable basis set for the second hyperpolarizabilites (γ). We use the values calculated at CCSD(T)/4-aug-cc-pVTZ level, and calculated at 4-aug-cc-pVTZ basis set by different methods to estimate whether the basis sets are good or bad. The MP2/aug-cc-pVDZ+ level is found to perform well.

关 键 词：超极化率 有限场(FF)法 基组 从头算 

分 类 号：O437[机械工程—光学工程]