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arXiv 0911.2615cond-mat.mtrl-sci
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固-液界面自由能的元吸附法模拟

Solid-liquid interface free energy through metadynamics simulations

Stefano Angioletti-Uberti, Michele Ceriotti, Mike W. Finnis, Peter D. Lee

摘要:

固液界面自由能γsl是控制凝固过程中形核和长大等现象的关键参数。在获得精确的实验值方面存在固有的困难,并且先前使用原子模拟来计算γsl的方法在计算上要求很高。本文提出了一种新的方法,即从用亚自洽方法重建的相变自由能图中得到γsl。我们将其应用到基准情况下的Lennard-Jones潜力和结果证实了以前获得的最可靠的数据。我们证明了我们的新方法的几个优点:它是简单的实施,强大的和免费的滞后问题,它允许一个严格的和无偏的估计的统计不确定性,它返回一个很好的估计的热力学极限与系统的大小只有几百个原子。因此,它是有吸引力的使用更现实和具体的模型的原子间的力量。

英文摘要:

The solid-liquid interface free energy γsl is a key parameter controlling nucleation and growth during solidification and other phenomena. There are intrinsic difficulties in obtaining accurate experimental values, and the previous approaches to compute γsl with atomistic simulations are computationally demanding. We propose a new approach, which is to obtain γsl from a free energy map of the phase transition reconstructed by metadynamics. We apply this to the benchmark case of a Lennard-Jones potential and the results confirm the most reliable data obtained previously. We demonstrate several advantages of our new approach: it is simple to implement, robust and free of hysteresis problems, it allows a rigorous and unbiased estimate of the statistical uncertainty and it returns a good estimate of of the thermodynamic limit with system sizes of a just a few hundred atoms. It is therefore attractive for using with more realistic and specific models of interatomic forces.

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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