On the molecular electronic flux: Role of nonadiabaticity and violation of conservation.
On the molecular electronic flux: Role of nonadiabaticity and violation of conservation.
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关于分子电子通量：非绝热性的作用和违反守恒定律。
DOI：
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发表时间：
2021
影响因子：
4.4
通讯作者：
K. Takatsuka
中科院分区：
文献类型：
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作者：
Kota Hanasaki;K. Takatsuka
分子内和分子间电子通量的分析对于研究分子电子波包演化的实时动力学，如阿秒激光化学和超快化学反应动力学，是至关重要的。在这里，我们解决两个相互关联的问题，作为一个关键的一致性条件的电子动力学的分子电子通量守恒定律。第一部分是关于低能化学反应中的电子动力学与“弱”非绝热性之间的密切关系。我们表明，绝热反应中的电子通量可以一致地再现考虑nonadiabaticity。这种非绝热性通常是弱的，因为它对核动力学没有重大影响，而它在电子动力学中起着重要作用。我们的讨论是基于电子波函数的非绝热扩展，其思想类似于由纳菲[J. Chem. Phys. 79，4950（1983）]开发的完全绝热形式主义，其最近也由Patchkovskii [J. Chem. Phys. 137，084109（2012）]重新表述。我们给出了简单的证明纳菲提出的理论断言使用时间依赖的混合量子经典框架和标准的微扰展开。在考虑通量守恒的情况下，我们证明了非绝热诱导通量实现了电子密度的绝热演化。换句话说，非绝热通量的发散等于电子密度沿着靶分子绝热时间演化的时间导数。第二个问题是关于通量的精确可计算性。通量的计算需要一个准确的表示（相对）量子相位，除了振幅因子，总波函数，并要求特别注意实际计算。本文是第一个直接处理这个问题，并显示如何明确出现的困难。在这样做的时候，我们发现，一些广泛接受的截断技术的静态性能计算的数值通量不守恒的潜在来源。我们还从理论上提出了替代策略，以实现更好的通量守恒。
Analysis of electron flux within and in between molecules is crucial in the study of real-time dynamics of molecular electron wavepacket evolution such as those in attosecond laser chemistry and ultrafast chemical reaction dynamics. We here address two mutually correlated issues on the conservation law of molecular electronic flux, which serves as a key consistency condition for electron dynamics. The first one is about a close relation between "weak" nonadiabaticity and the electron dynamics in low-energy chemical reactions. We show that the electronic flux in adiabatic reactions can be consistently reproduced by taking account of nonadiabaticity. Such nonadiabaticity is usually weak in the sense that it does not have a major effect on nuclear dynamics, whereas it plays an important role in electronic dynamics. Our discussion is based on a nonadiabatic extension of the electronic wavefunction similar in idea to the complete adiabatic formalism developed by Nafie [J. Chem. Phys. 79, 4950 (1983)], which has also recently been reformulated by Patchkovskii [J. Chem. Phys. 137, 084109 (2012)]. We give straightforward proof of the theoretical assertion presented by Nafie using a time-dependent mixed quantum-classical framework and a standard perturbation expansion. Explicitly taking account of the flux conservation, we show that the nonadiabatically induced flux realizes the adiabatic time evolution of the electronic density. In other words, the divergence of the nonadiabatic flux equals the time derivative of the electronic density along an adiabatic time evolution of the target molecule. The second issue is about the accurate computationability of the flux. The calculation of flux needs an accurate representation of the (relative) quantum phase, in addition to the amplitude factor, of a total wavefunction and demands special attention for practical calculations. This paper is the first one to approach this issue directly and show how the difficulties arise explicitly. In doing so, we reveal that a number of widely accepted truncation techniques for static property calculations are potential sources of numerical flux non-conservation. We also theoretically propose alternative strategies to realize better flux conservation.
影响因子：
64.8
作者：
Goulielmakis, Eleftherios;Loh, Zhi-Heng;Krausz, Ferenc
通讯作者：
Krausz, Ferenc