basis set. The numerical-analytic implementation of the second-order operator canonical Van Vleck perturbation theory was employed for predicting anharmonic IR and Raman scattering (RS) spectra of ACRF. To improve the anharmonic predictions, harmonic frequencies were replaced by their counterparts evaluated with the higher-level CCSD(T)/cc-pVTZ model, to form a "hybrid" PES. The original operator representation
测量了分辨率为0.1cm-1的
丙烯酰
氟(ACRF,CH2CHCFO)的新气相红外(IR)光谱,范围为4000-450cm-1。理论上从头算分子结构,全四次势能面(PES),偶极矩的立方表面和ACRF的s-trans和s-cis构象的极化率张量分量(电光学性质,
EOP)由下式计算:具有相关一致的Dunning三重ζ基集的二阶Møller-Plesset电子摄动理论。利用二阶算子规范Van Vleck微扰理论的数值分析实现方法预测了ACRF的非谐红外和拉曼散射(RS)光谱。为了改善非谐预测,用更高级别的CC
SD(T)/ cc-pVTZ模型评估其对应的谐波频率,从而形成“混合” PES。哈密顿量的原始算子表示形式被解析为准对角形式,并以谐波振荡器为基础进行了对角化,以解决强共振耦合问题。
EOP扩展的双规范转换使得能够预测IR / RS光谱中基本和多量子跃迁的积分强度。增强的带状分析增强了分配