Kempfer-Robertson Emily M, Haase Meagan N, Bersson Jonathan S, Avdic Irma, Thompson Lee M
Department of Chemistry, University of Louisville, Louisville, Kentucky40205, United States.
J Phys Chem A. 2022 Nov 3;126(43):8058-8069. doi: 10.1021/acs.jpca.2c04338. Epub 2022 Oct 21.
Difference approaches to the study of excited states have undergone a renaissance in recent years, with the development of a plethora of algorithms for locating self-consistent field approximations to excited states. Density functional theory is likely to offer the best balance of cost and accuracy for difference approaches, and yet there has been little investigation of how the parametrization of density functional approximations affects performance. In this work, we aim to explore the role of the global Hartree-Fock exchange parameter in tuning accuracy of different excitation types within the framework of the recently introduced difference projected double-hybrid density functional theory approach and contrast the performance with conventional time-dependent double-hybrid density functional theory. Difference projected double-hybrid density functional theory was demonstrated to give vertical excitation energies with average error and standard deviation with respect to multireference perturbation theory comparable to more expensive linear-response coupled cluster approaches ( 2020, 153, 074103). However, despite benchmarking of local excitations, there has been no investigation of the methods performance for charge transfer or Rydberg excitations. In this work we report a new benchmark of charge transfer, Rydberg, and local excited state vertical excitation energies and examine how the exact Hartree-Fock exchange affects the benchmark performance to provide a deeper understanding of how projection and nonlocal correlation balance differing sources of error in the ground and excited states.
近年来，随着大量用于确定激发态自洽场近似的算法的发展，研究激发态的不同方法经历了复兴。对于差分方法而言，密度泛函理论可能在成本和准确性之间提供了最佳平衡，然而，关于密度泛函近似的参数化如何影响性能的研究却很少。在这项工作中，我们旨在探讨全局哈特里-福克交换参数在最近引入的差分投影双杂化密度泛函理论方法框架内调整不同激发类型准确性方面的作用，并将其性能与传统的含时双杂化密度泛函理论进行对比。结果表明，差分投影双杂化密度泛函理论给出的垂直激发能相对于多参考微扰理论的平均误差和标准差，与更昂贵的线性响应耦合簇方法相当（2020, 153, 074103）。然而，尽管对局域激发进行了基准测试，但尚未对电荷转移或里德堡激发的方法性能进行研究。在这项工作中，我们报告了电荷转移、里德堡和局域激发态垂直激发能的新基准，并研究了精确的哈特里-福克交换如何影响基准性能，以更深入地理解投影和非局域相关如何平衡基态和激发态中不同的误差来源。
