Accelerating equilibration in first-principles molecular dynamics with orbital-free density functional theory
Accelerating equilibration in first-principles molecular dynamics with orbital-free density functional theory
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DOI：
10.1103/physrevresearch.4.043033
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发表时间：
2022-10-17
影响因子：
4.2
通讯作者：
Cangi, Attila
中科院分区：
文献类型：
--
作者：
Fiedler, Lenz;Moldabekov, Zhandos A.;Cangi, Attila
我们介绍了一种实用的混合方法，结合轨道自由密度泛函理论（DFT）与Kohn-Sham DFT加快第一性原理分子动力学模拟。利用无轨道密度泛函理论生成平衡离子构型，用于随后的Kohn-Sham密度泛函分子动力学。这导致模拟时间的大量减少，而不牺牲任何准确性。我们在不同大小和温度的系统中评估这一发现，直到温暖的致密物质制度。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，我们证明了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。我们的混合方案使系统的第一原理模拟温暖的致密物质，否则受到大量的原子和普遍的高温。此外，我们的发现提供了一个额外的动力和非相互作用的自由能泛函的轨道自由密度泛函。
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 configu-rations 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.