dSH扭曲程序的建立以及在两种基组(NBO, LFMO)下对扭曲分子的能量分解

介绍了d_SH 扭曲法产生的背景, 为d_SH扭曲法研究Mills-Nixon效应提供了一个自动化程序和方法. 通过在程序中引入随机函数模拟并代替了人工调节构型参数的过程, 提高了效率并拓宽了程序的应用范围. 利用此程序算得三元苯并分子C₆B₃H₃ 和C₆O₃的一系列的扭曲结构, 并利用自然键轨道(NBO)和定域片断分子轨道(LFMO)两种基组分别进行了NBO能量分析和Morokuma SCF能量分解, 并以动态的方式分析了扭曲过程中垂直共振能及其各分量的变化趋势, 比较了不同基组和不同分析方法下的扭曲的驱动力和阻力. 由分析知, 由于NBO基组的非绝对定域性和NBO能量分析方法的一次性对角化直接导致NBO基组及其能量分析方法在d_SH扭曲能量分析中的不合理.

Analysis of Molecular Distortion over the NBO andLFMO Basis Sets with the Automatic dSH Program

An automatic program to form the dSH geometry of a molecule was developed. The program was based on the random function, and various dSH geometries of each of the two molecules C6B3H3 and C6O3 were obtained from the program. Then the NBO energetic analysis and Morokuma SCF energy partition were performed, over the NBO and LFMO basis sets respectively, for each of these geometries, and these two energy partitions could provide any specific dSH geometry with the different values of the vertical reso-nance energy (VRE). At the same time, the driving force and resistant force for distorted molecules, obtained from the two different energy partitions over the NBO and LFMO basis sets, were compared. As a result, it is clear that the energy analysis results not only depend on the basis set but also on the analysis method. Furthermore, the results obtained from the NBO basis set and the NBO energetic analysis seem to be un-sound.