Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy.
J Chem Phys. 2023 Feb 28;158(8):084102. doi: 10.1063/5.0136392.
In this paper, we propose to compute the electronic circular dichroism (ECD) spectra of chiral molecules using a real-time propagation of the time-dependent Schrödinger equation (TDSE) in the space of electronic field-free eigenstates, by coupling TDSE with a given treatment of the electronic structure of the target. The time-dependent induced magnetic moment is used to compute the ECD spectrum from an explicit electric perturbation. The full matrix representing the transition magnetic moment in the space of electronic states is generated from that among pairs of molecular orbitals. In the present work, we show the ECD spectra of methyloxirane, of several conformers of L-alanine, and of the Λ-Co(acac) complex, computed from a singly excited ansatz of time-dependent density functional theory eigenstates. The time-domain ECD spectra properly reproduce the frequency-domain ones obtained in the linear-response regime and quantitatively agree with the available experimental data. Moreover, the time-domain approach to ECD allows us to naturally go beyond the ground-state rotationally averaged ECD spectrum, which is the standard outcome of the linear-response theory, e.g., by computing the ECD spectra from electronic excited states.
在本文中，我们提出了一种使用电子无场本征态空间中的含时薛定谔方程（TDSE）实时传播来计算手性分子的电子圆二色性（ECD）谱的方法，通过将 TDSE 与目标电子结构的给定处理方法相结合。通过显式电微扰来计算 ECD 谱时，我们使用时变感应磁矩。通过从分子轨道对之间的跃迁磁矩生成在电子态空间中的全矩阵。在目前的工作中，我们展示了从含时密度泛函理论本征态的单激发假设计算的甲基环氧乙烷、L-丙氨酸的几种构象体和 Λ-Co(acac)配合物的 ECD 谱。时域 ECD 谱适当地再现了在线性响应范围内获得的频域 ECD 谱，并且与可用的实验数据定量一致。此外，ECD 的时域方法允许我们自然地超越基于线性响应理论的基态旋转平均 ECD 谱，例如，通过从电子激发态计算 ECD 谱。
