论文标题
使用与杂种功能和平面波的摘要分子动力学对化学反应的自由能表面有效计算
Efficient Computation of Free Energy Surfaces of Chemical Reactions using Ab Initio Molecular Dynamics with Hybrid Functionals and Plane Waves
论文作者
论文摘要
使用密度功能理论（DFT）和平面波的始于分子动力学（AIMD）模拟通常使用在广义梯度近似（GGA）的水平下使用密度函数进行。采用混合密度功能的AIMD模拟引起了人们的极大兴趣，因为它比GGA功能更准确地描述了结构和动态性能。但是，使用混合功能和平面波集进行计算的计算成本至少比GGA功能高两个数量级。最近，我们提出了一种策略，该策略结合了自适应压缩的交换运算符公式和多个时间步的集成方案，以降低大约数量级的计算成本[J. J.化学物理。 151，151102（2019）]。在这项工作中，我们证明了这种方法在碱性水培养基中尤其是研究化学反应，特别是甲酰胺水解。通过使用良好的元动力学方案来驱动我们的实施，我们能够在杂交-DFT级别计算该反应的二维自由能表面。这里研究了PBE0（杂种）和PBE（GGA）功能在预测化学反应的自由能中的精度。
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 more accurate description of structural and dynamic properties than the GGA functionals. However, computational cost for carrying out calculations using hybrid functionals and plane wave basis set is at least two order of magnitude higher than 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 about 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 alkaline aqueous medium. By actuating our implementation with the well-sliced metadynamics scheme, we are able to compute the two-dimensional free energy surface of this reaction at the level of hybrid-DFT. Accuracy of PBE0 (hybrid) and PBE (GGA) functionals in predicting the free energetics of the chemical reaction is investigated here.
