Abstract

Ehrenfest method is commonly used for simulating photoexcitation dynamics in conjugated polymers. However, due to the expensive computational cost, the calculation of electronic excited states for long conjugated polymer chains in Ehrenfest simulations is still at the level of Hartree–Fock approximation. Here, we develop an approach to perform Ehrenfest simulations in terms of configuration interaction singles (CIS) that is beyond the Hartree–Fock approximation. With this approach, we simulate the relaxations of various photoinduced excited states in a single polymer chain. The simulations show that the photoinduced excited states relax to a mixed state very fast, in which the lowest excited state is dominated.In the excited-state relaxation processes, the electron and hole are not separated. We have also studied the exciton dissociation by external electric field, and find that the critical electric field to dissociate the exciton is much lower than that calculated by previous Ehrenfest simulations in terms of low-level excited-state calculations.

Graphic abstract

中文翻译：

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使用 Ehrenfest 方法模拟共轭聚合物中的光激发动力学与配置相互作用单

摘要

Ehrenfest 方法通常用于模拟共轭聚合物中的光激发动力学。然而，由于昂贵的计算成本，Ehrenfest 模拟中长共轭聚合物链的电子激发态计算仍处于 Hartree-Fock 近似的水平。在这里，我们开发了一种在配置交互单项 (CIS) 方面执行 Ehrenfest 模拟的方法，该方法超出了 Hartree-Fock 近似。通过这种方法，我们模拟了单个聚合物链中各种光致激发态的弛豫。模拟表明，光致激发态很快弛豫到混合态，其中最低激发态占主导地位。在激发态弛豫过程中，电子和空穴没有分离。

图形摘要