Chakraborty Arnab, Yuwono Stephen H, Deustua J Emiliano, Shen Jun, Piecuch Piotr
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
J Chem Phys. 2022 Oct 7;157(13):134101. doi: 10.1063/5.0100165.
We recently proposed a semi-stochastic approach to converging high-level coupled-cluster (CC) energetics, such as those obtained in the CC calculations with singles, doubles, and triples (CCSDT), in which the deterministic CC(P;Q) framework is merged with the stochastic configuration interaction Quantum Monte Carlo propagations [J. E. Deustua, J. Shen, and P. Piecuch, Phys. Rev. Lett. 119, 223003 (2017)]. In this work, we investigate the ability of the semi-stochastic CC(P;Q) methodology to recover the CCSDT energies of the lowest singlet and triplet states and the corresponding singlet-triplet gaps of biradical systems using methylene, (HFH), cyclobutadiene, cyclopentadienyl cation, and trimethylenemethane as examples.
我们最近提出了一种半随机方法，用于收敛高级耦合簇（CC）能量，例如在含单、双、三激发的耦合簇计算（CCSDT）中获得的能量，其中确定性CC(P;Q)框架与随机组态相互作用量子蒙特卡罗传播相结合[J. E. 德乌斯图亚、J. 沈和P. 皮丘克，《物理评论快报》119, 223003 (2017)]。在这项工作中，我们以亚甲基（HFH）、环丁二烯、环戊二烯基阳离子和三亚甲基甲烷为例，研究半随机CC(P;Q)方法恢复双自由基体系最低单重态和三重态的CCSDT能量以及相应单重态 - 三重态能隙的能力。
