Title: Characterization of Excited States in Time-Dependent Density Functional Theory Using Localized Molecular Orbitals Show Chinese title

Title: 基于定域分子轨道的时间依赖密度泛函理论激发态表征

Abstract: Localized molecular orbitals are often used for the analysis of chemical bonds, but they can also serve to efficiently and comprehensibly compute linear response properties. While conventional canonical molecular orbitals provide an adequate basis for the treatment of excited states, a chemically meaningful identification of the different excited-state processes is difficult within such a delocalized orbital basis. In this work, starting from an initial set of supermolecular canonical molecular orbitals, we provide a simple one-step top-down embedding procedure for generating a set of orbitals which are localized in terms of the supermolecule, but delocalized over each subsystem composing the supermolecule. Using an orbital partitioning scheme based on such sets of localized orbitals, we further present a procedure for the construction of local excitations and charge-transfer states within the linear response framework of time-dependent density functional theory (TDDFT). This procedure provides direct access to approximate diabatic excitation energies and, under the Tamm--Dancoff approximation, also their corresponding electronic couplings -- quantities that are of primary importance in modelling energy transfer processes in complex biological systems. Our approach is compared with a recently developed diabatization procedure based on subsystem TDDFT using projection operators, which leads to a similar set of working equations. Although both of these methods differ in the general localization strategies adopted and the type of basis functions (Slaters vs. Gaussians) employed, an overall decent agreement is obtained. Show Chinese abstract

Abstract: 局部分子轨道常用于化学键的分析，但它们也可以用于高效且易懂地计算线性响应性质。 虽然传统的规范分子轨道为激发态的处理提供了足够的基础，但在这种离域轨道基础上对不同的激发态过程进行化学上有意义的识别是困难的。 在本工作中，从一组初始的超分子规范分子轨道出发，我们提供了一种简单的一步式自上而下的嵌入方法，以生成一组在超分子范围内局域化的轨道，但在组成超分子的每个子系统上是离域的。 利用基于这些局域轨道集的轨道划分方案，我们进一步提出了一种在时间依赖密度泛函理论（TDDFT）的线性响应框架内构建局部激发和电荷转移态的方法。 该方法可以直接获得近似的非绝热激发能，并在Tamm--Dancoff近似下，还可以获得相应的电子耦合——这些量在模拟复杂生物系统中的能量传递过程时具有首要的重要性。 我们的方法与一种最近开发的基于投影算符的子系统TDDFT的非绝热化程序进行了比较，这导致了一组类似的方程。 尽管这两种方法在一般局域化策略和使用的基函数类型（Slater函数与高斯函数）方面有所不同，但总体上获得了良好的一致性。