de Wergifosse Marc, Grimme Stefan
Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstrasse 4, D-53115 Bonn, Germany.
J Phys Chem A. 2021 May 13;125(18):3841-3851. doi: 10.1021/acs.jpca.1c02362. Epub 2021 Apr 30.
We review recent developments in the framework of simplified quantum chemistry for excited state and optical response properties (sTD-DFT) and present future challenges for new method developments to improve accuracy and extend the range of application. In recent years, the scope of sTD-DFT was extended to molecular response calculations of the polarizability, optical rotation, first hyperpolarizability, two-photon absorption (2PA), and excited-state absorption for large systems with hundreds to thousands of atoms. The recently introduced spin-flip simplified time-dependent density functional theory (SF-sTD-DFT) variant enables an ultrafast treatment for diradicals and related strongly correlated systems. A few drawbacks were also identified, specifically for the computation of 2PA cross sections. We propose solutions to this problem and how to generally improve the accuracy of simplified schemes. New possible simplified schemes are also introduced for strongly correlated systems, e.g., with a second-order perturbative correlation correction. Interpretation tools that can extract chemical structure-property relationships from excited state or response calculations are also discussed. In particular, the recently introduced method-agnostic RespA approach based on natural response orbitals (NROs) as the key concept is employed.
我们回顾了用于激发态和光学响应特性的简化量子化学框架（sTD-DFT）的最新进展，并提出了新方法开发在提高准确性和扩展应用范围方面的未来挑战。近年来，sTD-DFT的范围已扩展到具有数百至数千个原子的大型系统的极化率、旋光性、第一超极化率、双光子吸收（2PA）和激发态吸收的分子响应计算。最近引入的自旋翻转简化含时密度泛函理论（SF-sTD-DFT）变体能够对双自由基和相关强关联系统进行超快处理。还发现了一些缺点，特别是在2PA截面的计算方面。我们提出了解决这个问题的方法以及如何普遍提高简化方案的准确性。还针对强关联系统引入了新的可能的简化方案，例如具有二阶微扰相关校正的方案。还讨论了能够从激发态或响应计算中提取化学结构-性质关系的解释工具。特别是，采用了最近引入的基于自然响应轨道（NROs）作为关键概念的与方法无关的RespA方法。
