A Subsystem TDDFT Approach for Solvent Screening Effects on Excitation Energy Transfer Couplings
A Subsystem TDDFT Approach for Solvent Screening Effects on Excitation Energy Transfer Couplings
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DOI：
10.1021/ct100138k
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发表时间：
2010-06-01
影响因子：
5.5
通讯作者：
Mennucci, Benedetta
中科院分区：
文献类型：
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作者：
Neugebauer, Johannes;Curutchet, Carles;Mennucci, Benedetta
我们提出了一种计算激发-能量转移(EET)耦合中溶剂屏蔽效应的QM/QM方法。该方法采用子系统依赖于时间的密度泛函理论形式[J.太棒了。2007、126、134116]，并明确包括考虑环境响应的溶剂激发态。研究了如何提高这些计算的效率，以便在充分考虑环境响应的同时处理具有非常大的溶剂化壳层的体系。特别地，我们引入了一种根据溶剂激发态对环境极化的近似贡献权重来选择溶剂激发态的准则。作为一个模型系统，我们研究了水团簇中的二聚体，并与最近关于凝聚相EET耦合的极化QM/MM方法进行了比较[J。理论计算。2009、5、1838]。在溶剂筛选的描述中发现了很好的总体一致性。对于最接近的水分子的影响，可以观察到偏差，而外部溶剂化壳层引入的屏蔽在这两种方法中都非常相似。因此，我们的结果有助于确定与发色团的环境响应效应之间的距离可以安全地用经典模型来近似。
We present a QM/QM approach for the calculation of solvent screening effects on excitation-energy transfer (EET) couplings. The method employs a subsystem time-dependent density-functional theory formalism [J. Chem. Phys. 2007, 126, 134116] and explicitly includes solvent excited states to account for the environmental response. It is investigated how the efficiency of these calculations can be enhanced in order to treat systems with very large solvation shells while fully including the environmental response. In particular, we introduce a criterion to select solvent excited states according to their approximate contribution weight to the environmental polarization. As a model system, we investigate the perylene diimide dimer in a water cluster in comparison to a recent polarizable QM/MM method for EET couplings in the condensed phase [J. Chem. Theory Comput. 2009, 5, 1838]. A good overall agreement in the description of the solvent screening is found. Deviations can be observed for the effect of the closest water molecules, whereas the screening introduced by outer solvation shells is very similar in both methods. Our results can thus be helpful to determine at which distance from a chromophore environmental response effects may safely be approximated by classical models.