Domenis Nicola, Grobas Illobre Pablo, Marsili Margherita, Stener Mauro, Toffoli Daniele, Coccia Emanuele
Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L Giorgieri 1, 34127 Trieste, Italy.
Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
Molecules. 2023 Jul 26;28(15):5671. doi: 10.3390/molecules28155671.
In the present work, we apply recently developed real-time descriptors to study the time evolution of plasmonic features of pentagonal Ag clusters. The method is based on the propagation of the time-dependent Schrödinger equation within a singly excited TDDFT ansatz. We use transition contribution maps (TCMs) and induced density to characterize the optical longitudinal and transverse response of such clusters, when interacting with pulses resonant with the low-energy (around 2-3 eV, A1) size-dependent or the high-energy (around 4 eV, E1) size-independent peak. TCMs plots on the analyzed clusters, Ag25+ and Ag43+ show off-diagonal peaks consistent with a plasmonic response when a longitudinal pulse resonant at A1 frequency is applied, and dominant diagonal spots, typical of a molecular transition, when a transverse E1 pulse is employed. Induced densities confirm this behavior, with a dipole-like charge distribution in the first case. The optical features show a time delay with respect to the evolution of the external pulse, consistent with those found in the literature for real-time TDDFT calculations on metal clusters.
在本工作中，我们应用最近开发的实时描述符来研究五角形银团簇等离子体特征的时间演化。该方法基于含时薛定谔方程在单激发含时密度泛函理论假设下的传播。当与与低能量（约2 - 3 eV，A1）尺寸相关峰或高能量（约4 eV，E1）尺寸无关峰共振的脉冲相互作用时，我们使用跃迁贡献图（TCM）和感应密度来表征此类团簇的光学纵向和横向响应。在分析的团簇Ag25 +和Ag43 +上的TCM图显示，当施加在A1频率共振的纵向脉冲时，出现与等离子体响应一致的非对角峰；而当使用横向E1脉冲时，出现典型分子跃迁的占主导的对角斑点。感应密度证实了这种行为，在第一种情况下呈现偶极状电荷分布。光学特征相对于外部脉冲的演化显示出时间延迟，这与文献中关于金属团簇实时含时密度泛函理论计算的结果一致。
