【摘要】 应用密度泛函理论 (DFT)的B3LYP和B3PW91两种方法 ,在 6 3 11+G 和aug cc pVTZ基组水平上 ,分别优化了CS2 可能存在的非线形单重态和三重态构型 ,在全局势能面上共发现 3个单重态 (电子态 1 A1 )和 5个三重态 (电子态分别为 3A2 、3B2 和 3B2 )的非线形CS2 异构体 ,正则振动频率分析证明所得到构型均是位能面上的极小 .计算所得CS2 异构体的相对能量顺序为 4t3B2 <a1 A1 <1t3A2 <3t3B1 <5t3B2 <2t3B1 <b1 A1 <c1 A1 .成键分析表明 ,这些异构体的结构参数和振动频率是与不同构型中电子占据的前线轨道和轨道耦合方式的不同紧密相连的更多还原

【Abstract】 The geometrical optimizations on nonlinear CS 2 in the singlet and triplet stateshave been made using two Density Function Theory (DFT) methods (B3LYP and B3PW91)with 6 311+G * and aug cc pVTZ basis sets. Three Singlet states 1A 1 and five triplet states ( 3A 2、 3B 1 and 3B 2)have been found, and the frequency analysis confirms that there are no image frequencies for these states, indicating that they are geniune minima at the potential energy surface. At their respective equilibrium geometries, the lowest lying electronic states are predicted to have an energy ordering by 4t 3B 2<a 1A 1<1t 3A 2<3t 3B 1<5t 3B 2<2t 3B 1<b 1A 1<c 1A 1 through analysis of orbit interaction, the structural parameters and vibration frequencies of the isomers are connected closely with the differences of both occupations of HOMO LUMO and the modes of coupling in different conformations.更多还原