Shumberger Brendan M, Crawford T Daniel
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.
J Chem Theory Comput. 2024 Aug 13;20(16):7254-63. doi: 10.1021/acs.jctc.4c00747.
We present the first single-reference calculations of the atomic axial tensors (AATs) with wave function-based methods including dynamic electron correlation effects using second-order Møller-Plesset perturbation theory (MP2) and configuration interaction doubles (CID). Our implementation involves computing the overlap of numerical derivatives of the correlated wave functions with respect to both nuclear displacement coordinates and the external magnetic field. Out test set included three small molecules, including the axially chiral hydrogen molecule dimer and ()-hydrogen peroxide, and the achiral HO. For our molecular test set, we observed deviations of the AATs for MP2 and CID from that of the Hartree-Fock (HF) method upward of 49%, varying with the choice of basis set. For ()-hydrogen peroxide, electron correlation effects on the vibrational circular dichroism (VCD) rotatory strengths and corresponding spectra were particularly significant, with maximum deviations of the rotatory strengths of 62 and 49% for MP2 and CID, respectively, using our largest basis set. The inclusion of dynamic electron correlation to the computation of the AATs can have a significant impact on the resulting rotatory strengths and VCD spectra.
我们展示了首次使用基于波函数的方法对原子轴向张量（AATs）进行的单参考计算，其中包括使用二阶莫雷-普列斯特定理（MP2）和双激发组态相互作用（CID）的动态电子相关效应。我们的实现涉及计算相关波函数相对于核位移坐标和外部磁场的数值导数的重叠。我们的测试集包括三个小分子，包括轴向手性氢分子二聚体和（）-过氧化氢，以及非手性的HO。对于我们的分子测试集，我们观察到MP2和CID的AATs与哈特里-福克（HF）方法的偏差超过49%，这随基组的选择而变化。对于（）-过氧化氢，电子相关效应在振动圆二色性（VCD）旋转强度和相应光谱上尤为显著，使用我们最大的基组时，MP2和CID的旋转强度最大偏差分别为62%和49%。将动态电子相关纳入AATs的计算对所得的旋转强度和VCD光谱可能有显著影响。
