Weidlich Anna M, Dreuw Andreas
Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Heidelberg, Germany.
J Comput Chem. 2025 Apr 15;46(10):e70095. doi: 10.1002/jcc.70095.
Acenes are a class of molecules that enjoy popularity in both experimental and theoretical fields of research for their diverse areas of application and unique electronic structure. One particular aspect of interest lies in their electronic absorption spectra, which have been thoroughly investigated both experimentally and theoretically. In this work, the electronically excited states of radical cations of acenes from naphthalene to dodecacene are investigated using algebraic diagrammatic construction (ADC) methods and different time-dependent density functional theory (TD-DFT) exchange-correlation kernels. The performance of the employed ADC methods and different DFT functionals is assessed using experimental values as benchmarks. Using ADC, it is then shown that excited states typical for neutral acenes are retained in their radical cation counterparts, while additional states emerge due to excitations into the singly-occupied molecular orbital (SOMO). Finally, the evolution of the excitation energies in neutral as well as cationic acenes with increasing length is investigated using TD-DFT, where a special focus lies on the correct description of longer acenes using single-reference methods.
并苯是一类因其多样的应用领域和独特的电子结构而在实验和理论研究领域都备受关注的分子。一个特别受关注的方面在于它们的电子吸收光谱，这在实验和理论上都已得到充分研究。在这项工作中，使用代数图示构建（ADC）方法和不同的含时密度泛函理论（TD-DFT）交换关联核，研究了从萘到十二并苯的并苯自由基阳离子的电子激发态。以实验值为基准评估所采用的ADC方法和不同DFT泛函的性能。使用ADC表明，中性并苯典型的激发态在其自由基阳离子对应物中得以保留，同时由于激发到单占据分子轨道（SOMO）而出现了额外的状态。最后，使用TD-DFT研究了中性和阳离子并苯中激发能随长度增加的演变，其中特别关注使用单参考方法对较长并苯的正确描述。
