Plane wave basis sets offer many advantages in ab initio molecular dynamics due to their efficiency and simplicity. In combination with hybrid density functionals, they become computationally expensive due to the evaluation of the Hartree-Fock exchange energy. The computational cost can be significantly reduced by screening the Kohn-Sham orbital products after localizing the orbitals in real space. However, such a procedure introduces apparent errors in the wavefunctions and nuclear forces resulting in unstable dynamics. It is shown here that a noise-stabilized dynamics approach can overcome this problem and at the same time permits using insufficiently converged wavefunctions for evaluating atomic forces. In this way, we achieve significant speed up even for a small system containing about 100 atoms. After benchmarking the accuracy and efficiency of this approach, we use it in combination with well-sliced metadynamics to compute the free energy barrier of formamide hydrolysis in alkaline aqueous medium. These results provide insight into the error of the Perdew-Burke-Ernzerhof functional in predicting the free energy barrier for hydrolysis reactions in water.

中文翻译：

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混合函数和平面波增强了采样和自由能计算，可用于化学反应

平面波基集从头开始提供许多优势分子动力学归因于其效率和简单性。结合混合密度函数，由于对Hartree-Fock交换能量的评估，它们在计算上变得昂贵。在真实空间中定位了轨道之后，通过筛选Kohn-Sham轨道产品，可以显着降低计算成本。但是，这样的过程会在波函数和核力中引入明显的误差，从而导致动力学不稳定。此处示出了噪声稳定的动力学方法可以克服该问题，并且同时允许使用不充分收敛的波函数来评估原子力。这样，即使对于包含约100个原子的小型系统，我们也可以显着提高速度。在对这种方法的准确性和效率进行基准测试之后，我们将其与精细的元动力学结合使用，以计算碱性水溶液介质中甲酰胺水解的自由能垒。这些结果提供了Perdew-Burke-Ernzerhof函数在预测水中水解反应的自由能垒时的错误的见解。