Hodecker Manuel, Rehn Dirk R, Norman Patrick, Dreuw Andreas
Interdisciplinary Center for Scientific Computing (IWR), Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 205, D-69120 Heidelberg, Germany.
Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, Roslagstullsbacken 15, S-10691 Stockholm, Sweden.
J Chem Phys. 2019 May 7;150(17):174105. doi: 10.1063/1.5081665.
The modification of the algebraic-diagrammatic construction (ADC) scheme for the polarization propagator using ground-state coupled-cluster (CC) instead of Møller-Plesset (MP) amplitudes, referred to as CC-ADC, is extended to the calculation of molecular properties, in particular, dipole polarizabilities. Furthermore, in addition to CC with double excitations (CCD), CC with single and double excitations (CCSD) amplitudes can be used, also in the second-order transition moments of the ADC(3/2) method. In the second-order CC-ADC(2) variants, the MP correlation coefficients occurring in ADC are replaced by either CCD or CCSD amplitudes, while in the F/CC-ADC(2) and F/CC-ADC(3/2) variants, they are replaced only in the second-order modified transition moments. These newly implemented variants are used to calculate the static dipole polarizability of several small- to medium-sized molecules, and the results are compared to the ones obtained by full configuration interaction or experiment. It is shown that the results are consistently improved by the use of CC amplitudes, in particular, for aromatic systems such as benzene or pyridine, which have proven to be difficult cases for standard ADC approaches. In this case, the second-order CC-ADC(2) and F/CC-ADC(2) variants yield significantly better results than the standard third-order ADC(3/2) method, at a computational cost amounting to only about 1% of the latter.
将用于极化传播子的代数-图解构建（ADC）方案进行修改，使用基态耦合簇（CC）而非莫勒-普列斯特定理（MP）振幅，即所谓的CC-ADC，已扩展至分子性质的计算，尤其是偶极极化率的计算。此外，除了双激发耦合簇（CCD），单激发和双激发耦合簇（CCSD）振幅也可使用，同样用于ADC(3/2)方法的二阶跃迁矩计算。在二阶CC-ADC(2)变体中，ADC中出现的MP相关系数被CCD或CCSD振幅取代，而在F/CC-ADC(2)和F/CC-ADC(3/2)变体中，仅在二阶修正跃迁矩中进行替换。这些新实现的变体用于计算几个中小尺寸分子的静态偶极极化率，并将结果与通过完全组态相互作用或实验获得的结果进行比较。结果表明，使用CC振幅可使结果持续改善，特别是对于苯或吡啶等芳香体系，这些体系已证明是标准ADC方法的难题。在这种情况下，二阶CC-ADC(2)和F/CC-ADC(2)变体产生的结果明显优于标准三阶ADC(3/2)方法，而计算成本仅约为后者的1%。
