论文标题
具有无轨道密度理论的第一原理分子动力学中的加速平衡
Accelerating Equilibration in First-Principles Molecular Dynamics with Orbital-Free Density Functional Theory
论文作者
论文摘要
我们引入了一种实用的混合方法,该方法将无轨道密度功能理论(DFT)与Kohn-Sham DFT相结合,以加快第一原理分子动力学模拟。使用无轨道DFT生成平衡的离子构型,以进行随后的Kohn-Sham DFT分子动力学。这导致了模拟时间的大量减少,而无需任何精确牺牲。我们评估了跨不同大小和温度系统的发现,直到温暖的密集物质制度。为此,我们使用代表离子配置的径向分布函数的时间序列之间的余弦距离。同样,我们表明,这种混合方法的平衡离子构型显着提高了取代Kohn-Sham DFT的机器学习模型的准确性。我们的混合方案实现了系统的第一原理模拟温暖的密集物质,否则这些原子和普遍的高温会阻碍。此外,我们的发现为开发无轨道DFT的动力学和非相互作用的自由能功能提供了额外的动力。
We introduce a practical hybrid approach that combines orbital-free density functional theory (DFT) with Kohn-Sham DFT for speeding up first-principles molecular dynamics simulations. Equilibrated ionic configurations are generated using orbital-free DFT for subsequent Kohn-Sham DFT molecular dynamics. This leads to a massive reduction of the simulation time without any sacrifice in accuracy. We assess this finding across systems of different sizes and temperature, up to the warm dense matter regime. To that end, we use the cosine distance between the time series of radial distribution functions representing the ionic configurations. Likewise, we show that the equilibrated ionic configurations from this hybrid approach significantly enhance the accuracy of machine-learning models that replace Kohn-Sham DFT. Our hybrid scheme enables systematic first-principles simulations of warm dense matter that are otherwise hampered by the large numbers of atoms and the prevalent high temperatures. Moreover, our finding provides an additional motivation for developing kinetic and noninteracting free energy functionals for orbital-free DFT.