论文标题
评估简化的耦合群集方法在F0 actacinide化合物中的电子激发态
Assessing the accuracy of simplified Coupled Cluster methods for electronic excited states in f0 actinide compounds
论文作者
论文摘要
我们仔细检查了运动耦合簇方程（EOM-CC）方法的不同变体，以预测封闭壳actactinide物种中的电子激发能和激发状态势能表面。我们将分析重点放在各种最近提出的对耦合簇双打（PCCD）模型[J.〜Chem。 15，18--24（2019）]并将其性能与常规的EOM-CCSD方法以及具有扰动三元ansatz的完全重归于的EOM-CCSD进行了比较。由于单参照PCCD模型使我们能够有效地描述静态/非动力电子相关性，而动态电子相关性则由\ textit {a posteriori}解释，因此，基于PCCD的基于PCCD的方法代表了准确性和计算成本之间的良好损害。当用拉伸键对含有阳离子化合物的化合物的电子结构进行建模时，这种特征尤其有利。我们的工作表明，基于EOM-PCCD的方法可靠地预测含有thrium，铀和protactinium原子的小阳离子构建块的电子光谱。具体而言，当使用EOM-PCCD-LCCSD变体时，通过常规EOM-CCSD方法获得的绝热和垂直激发能的标准误差减少了2倍，导致平均误差为0.05 eV，标准偏差为0.25 eV。
We scrutinize the performance of different variants of equation of motion coupled cluster (EOM-CC) methods to predict electronic excitation energies and excited state potential energy surfaces in closed-shell actinide species. We focus our analysis on various recently presented pair coupled cluster doubles (pCCD) models [J.~Chem.~Phys., 23, 234105 (2016) and J.~Chem.~Theory~Comput. 15, 18--24 (2019)] and compare their performance to the conventional EOM-CCSD approach and to the completely renormalized EOM-CCSD with perturbative triples ansatz. Since the single-reference pCCD model allows us to efficiently describe static/nondynamic electron correlation, while dynamical electron correlation is accounted for \textit{a posteriori}, the investigated pCCD-based methods represent a good compromise between accuracy and computational cost. Such a feature is particularly advantageous when modelling electronic structures of actinide-containing compounds with stretched bonds. Our work demonstrates that EOM-pCCD-based methods reliably predict electronic spectra of small actinide building blocks containing thorium, uranium, and protactinium atoms. Specifically, the standard errors in adiabatic and vertical excitation energies obtained by the conventional EOM-CCSD approach are reduced by a factor of 2 when employing the EOM-pCCD-LCCSD variant resulting in a mean error of 0.05 eV and a standard deviation of 0.25 eV.
