arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2108.05461cond-mat.mtrl-sci
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用EXAFS谱验证面心立方和体心立方金属的矩张量势

Validation of moment tensor potentials for fcc and bcc metals using EXAFS spectra

Alexander V. Shapeev, Dmitry Bocharov, Alexei Kuzmin

摘要:

首次使用实验EXAFS光谱验证了材料的机器学习势,即矩张量势(MTP)。采用主动学习算法拟合密度泛函理论(DFT)的计算结果,得到了四种金属(体心立方结构的W和Mo,面心立方结构的Cu和Ni)的MTPs。MTP的准确性进行了评估,通过比较金属K-边缘EXAFS光谱实验获得的结果和计算的分子动力学(MD)模拟。以Ni为例,证明了该方法对MD和DFT模型各个方面的灵敏度。使用推荐的PAW赝势,发现W,Mo和Cu具有良好的一致性,而Ni需要具有18价电子的更准确的赝势以实现类似的一致性。EXAFS谱的使用允许一个估计MTP的能力,在再现平均和动态原子结构。

英文摘要:

Machine-learning potentials for materials, namely the moment tensor potentials (MTPs), were validated using experimental EXAFS spectra for the first time. The MTPs for four metals (bcc W and Mo, fcc Cu and Ni) were obtained by the active learning algorithm of fitting to the results of the calculations using density functional theory (DFT). The MTP accuracy was assessed by comparing metal K-edge EXAFS spectra obtained experimentally and computed from the results of molecular dynamics (MD) simulations. The sensitivity of the method to various aspects of the MD and DFT models was demonstrated using Ni as an example. Good agreement was found for W, Mo and Cu using the recommended PAW pseudopotentials, whereas a more accurate pseudopotential with 18 valence electrons was required for Ni to achieve a similar agreement. The use of EXAFS spectra allows one to estimate the MTP ability in reproducing both average and dynamic atomic structures.

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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