Assessment of TD‐DFT‐ and TD‐HF‐based approaches for the prediction of exciton coupling parameters, potential energy curves, and electronic characters of electronically excited aggregates
Assessment of TD‐DFT‐ and TD‐HF‐based approaches for the prediction of exciton coupling parameters, potential energy curves, and electronic characters of electronically excited aggregates
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DOI：
10.1002/jcc.21781
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发表时间：
2011-07
影响因子：
3
通讯作者：
Wenlan Liu;Volker Settels;P. Harbach;A. Dreuw;R. Fink;B. Engels
中科院分区：
文献类型：
--
作者：
Wenlan Liu;Volker Settels;P. Harbach;A. Dreuw;R. Fink;B. Engels
研究了含时Hartree-Fock（TD-HF）和含时密度泛函理论（TD-DFT）等线性响应方法预测3，4; 9，10-四羧基-苝酰亚胺（PBI）聚集体激发态性质的可靠性. PBI的二聚体模型作为一个功能的扭转运动的单体，这是之前被证明是一个重要的分子间的坐标在这些聚集体的研究。基态和两个能量最低的中性激发态和电荷转移（CT）态的势能曲线是用近似耦合簇单和双（SCS-CC 2）方法的自旋分量标度修正作为色散校正TD-HF和一系列TD-DFT方法的基准得到的。高度精确的SCS-CC 2结果用于评估其他计算要求较低的方法。TD-HF预测了与SCS-CC 2相似的势能曲线和跃迁偶极矩，以及中性和CT状态的正确顺序。这支持了基于TD-HF数据发现的激子捕获机制。然而，研究的TD-DFT方法通常为激发态提供了相反的特征。因此，这些TD-DFT结果对于这些染料聚集体的光学性质具有不可接受的大误差。© 2011 Wiley Periodicals，Inc. J Comput Chem 2011
The reliability of linear response approaches such as time‐dependent Hartree–Fock (TD‐HF) and time‐dependent density functional theory (TD‐DFT) for the prediction of the excited state properties of 3,4;9,10‐tetracarboxylic‐perylene‐bisimide (PBI) aggregates is investigated. A dimer model of PBI is investigated as a function of a torsional motion of the monomers, which was shown before to be an important intermolecular coordinate in these aggregates. The potential energy curves of the ground state and the two energetically lowest neutral excited and charge‐transfer (CT) states were obtained with the spin‐component scaling modification of the approximate coupled‐cluster singles‐and‐doubles (SCS‐CC2) method as a benchmark for dispersion corrected TD‐HF and a range of TD‐DFT approaches. The highly accurate SCS‐CC2 results are used to assess the other, computationally less demanding methods. TD‐HF predicts similar potential energy curves and transition dipole moments as SCS‐CC2, as well as the correct order of neutral and CT states. This supports an exciton trapping mechanism, which was found on the basis of TD‐HF data. However, the investigated TD‐DFT methods provide generally the opposite character for the excited states. As a consequence, these TD‐DFT results have unacceptably large errors for optical properties of these dye aggregates. © 2011 Wiley Periodicals, Inc. J Comput Chem 2011