arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2209.01437physics.chem-phcond-mat.mtrl-sciphysics.comp-ph
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水溶液Fe $^{2+}$ /Fe $^{3+}$氧化还原反应的杂化泛函和平面波从头算分子动力学研究

Hybrid Functional and Plane Waves based Ab Initio Molecular Dynamics Study of the Aqueous Fe$^{2+}$/Fe$^{3+}$ Redox Reaction

Sagarmoy Mandal, Ritama Kar, Bernd Meyer, Nisanth N. Nair

摘要:

基于Kohn-Sham密度泛函理论和平面波基组的从头算分子动力学(AIMD)模拟是研究溶液中复杂反应的有力工具,如水中涉及Fe $^{2+}$ /Fe $^{3+}$离子的电子转移(ET)反应。在大多数情况下,这样的模拟是在广义梯度近似(GGA)的水平使用密度泛函。模拟ET反应的挑战是由于不可避免的自相互作用误差(SIE),GGA泛函在预测这种开壳层系统的性质时质量较差。虽然混合泛函可以最大限度地减少SIE,但对于含有~100个原子的系统,该理论水平的AIMD通常比GGA慢150倍。在报告的几种方法中,使用混合泛函加速AIMD模拟,噪声稳定MD(NSMD)程序,以及使用局部轨道计算所需的交换积分,是一个有吸引力的选择。在这项工作中,我们展示了应用NSMD方法研究Fe $^{2+}$ /Fe $^{3+}$在水中的氧化还原反应。它示出在这里,长AIMD轨迹的混合密度泛函的水平,可以使用这种方法获得。从这些模拟计算的水溶液的Fe $^{2+}$ /Fe $^{3+}$系统的氧化还原性能进行了比较与可用的实验数据进行验证。

英文摘要:

Kohn-Sham density functional theory and plane wave basis set based ab initio molecular dynamics (AIMD) simulation is a powerful tool for studying complex reactions in solutions, such as electron transfer (ET) reactions involving Fe$^{2+}$/Fe$^{3+}$ ions in water. In most cases, such simulations are performed using density functionals at the level of Generalized Gradient Approximation (GGA). The challenge in modelling ET reactions is the poor quality of GGA functionals in predicting properties of such open-shell systems due to the inevitable self-interaction error (SIE). While hybrid functionals can minimize SIE, AIMD at that level of theory is typically 150 times slower than GGA for systems containing ~100 atoms. Among several approaches reported to speed-up AIMD simulations with hybrid functionals, the noise-stabilized MD (NSMD) procedure, together with the use of localized orbitals to compute the required exchange integrals, is an attractive option. In this work, we demonstrate the application of the NSMD approach for studying the Fe$^{2+}$/Fe$^{3+}$ redox reaction in water. It is shown here that long AIMD trajectories at the level of hybrid density functionals can be obtained using this approach. Redox properties of the aqueous Fe$^{2+}$/Fe$^{3+}$ system computed from these simulations are compared with the available experimental data for validation.

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