Ab initio molecular dynamics (AIMD) simulations employing density functional theory (DFT) and plane waves are routinely carried out using density functionals at the level of generalized gradient approximation (GGA). AIMD simulations employing hybrid density functionals are of great interest as it offers a more accurate description of structural and dynamic properties than the GGA functionals. However, the computational cost for carrying out calculations using hybrid functionals and plane wave basis set is at least two orders of magnitude higher than that using GGA functionals. Recently, we proposed a strategy that combined the adaptively compressed exchange operator formulation and the multiple time step integration scheme to reduce the computational cost by an order of magnitude [J. Chem. Phys. 151, 151102 (2019)]. In this work, we demonstrate the application of this method to study chemical reactions, in particular, formamide hydrolysis in an alkaline aqueous medium. By actuating our implementation with the well‐sliced metadynamics scheme, we can compute the two‐dimensional free energy surface of this reaction at the level of hybrid‐DFT. This work also investigates the accuracy of the PBE0 (hybrid) and the PBE (GGA) functionals in predicting the free energetics of this chemical reaction.

中文翻译：

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使用具有混合泛函和平面波的从头算分子动力学有效计算化学反应的自由能面

采用密度泛函理论 (DFT) 和平面波的从头算分子动力学 (AIMD) 模拟通常使用广义梯度近似 (GGA) 级别的密度泛函进行。采用混合密度泛函的 AIMD 模拟非常有趣，因为它比 GGA 泛函提供了更准确的结构和动态特性描述。然而，使用混合泛函和平面波基组进行计算的计算成本至少比使用 GGA 泛函高两个数量级。最近，我们提出了一种策略，将自适应压缩交换算子公式和多时间步集成方案相结合，将计算成本降低一个数量级 [J. 化学 物理。151, 151102 (2019)]。在这项工作中，我们展示了这种方法在研究化学反应中的应用，特别是在碱性水介质中的甲酰胺水解。通过使用切片良好的元动力学方案来驱动我们的实现，我们可以在混合 DFT 的水平上计算该反应的二维自由能表面。这项工作还研究了 PBE0（混合）和 PBE（GGA）泛函在预测该化学反应的自由能量方面的准确性。