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arXiv 2402.15419cond-mat.mtrl-sci
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使用原子间势的硅原子模拟中的不确定性量化

Uncertainty Quantification in Atomistic Simulations of Silicon using Interatomic Potentials

I. R. Best, T. J. Sullivan, J. R. Kermode

AI总结:

针对原子模拟中参数化原子间势带来的结果误差问题,本研究构建ACE势集成,结合DFT训练数据与共形预测为硅的多个物理量提供校准误差棒,并评估不同势和训练集对不确定性边界的影响。

摘要:

原子模拟通常依赖原子间势来获取比密度泛函理论(DFT)等第一性原理方法所能达到的更大的时间和长度尺度。然而,由于参数化势通常无法重现给定系统的真实势能面,我们可以预期从模拟计算得到的感兴趣物理量的准确性会下降,误差会增加。因此,量化原子模拟输出的不确定性是重要且必要的步骤,这样才能对结果有信心,并拥有可用的指标来探索上述模拟的改进方向。在此,我们通过构建Atomic Cluster Expansion(ACE,原子团簇展开)势的集成,并结合DFT训练数据使用Conformal Prediction(共形预测),为硅的多个感兴趣物理量提供有意义的、经过校准的误差棒,这些物理量包括:体积模量、弹性常数、弛豫空位形成能以及空位迁移势垒。我们还评估了一系列不同的势和训练集对不确定性边界的影响。

英文摘要:

Atomistic simulations often rely on interatomic potentials to access greater time- and length- scales than those accessible to first principles methods such as density functional theory (DFT). However, since a parameterised potential typically cannot reproduce the true potential energy surface of a given system, we should expect a decrease in accuracy and increase in error in quantities of interest calculated from simulations. Quantifying the uncertainty on the outputs of atomistic simulations is thus an important, necessary step so that there is confidence in results and available metrics to explore improvements in said simulations. Here, we address this research question by forming ensembles of Atomic Cluster Expansion (ACE) potentials, and using Conformal Prediction with DFT training data to provide meaningful, calibrated error bars on several quantities of interest for silicon: the bulk modulus, elastic constants, relaxed vacancy formation energy, and the vacancy migration barrier. We evaluate the effects on uncertainty bounds using a range of different potentials and training sets.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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