通过第一原则分子动力学模拟计算的化温度的高估
Koun Shirai1,2, Hiroyoshi Momida3, Kazunori Sato4
1Vietnam Japan University, Vietnam National University, Hanoi, Luu Huu Phuoc Road, My Dinh 1 Ward, Nam Tu Liem District, Hanoi, Vietnam.
概括
对化温度 (Tm) 的分子动力学模拟可能不准确. 用约100个原子进行的亚底离子模拟显示Si和Na的良好一致性,这表明LDA/GGA错误导致氧化物的高估值.
科学领域:
- 计算材料科学 计算材料科学
- 凝聚物质物理学 凝聚物质物理学
- 物理化学 物理化学
背景情况:
- 使用分子动力学 (MD) 模拟计算化温度 (Tm) 是具有挑战性的,第一原则的MD (FP-MD) 经常产生显著的高估值.
- 对Tm的FP-MD的准确性受到模拟参数和材料特性的影响,需要仔细评估.
研究的目的:
- 评估FP-MD模拟用于计算各种固体化温度的准确性.
- 确定导致Tm计算过高估计的因素,特别是氧化物材料.
主要方法:
- 使用了第一原理分子动力学 (FP-MD) 模拟,强调亚亚巴特条件 (没有恒温器),以准确捕捉液态平衡.
- 研究了细胞大小 (约100个原子) 和过渡宽度 (Wm) 对 (Si) 和 (Na) 等元素的Tm计算的影响.
主要成果:
- 用约100个原子进行的阿迪亚巴特FP-MD模拟,在过渡宽度 (Wm) 引入的不确定性范围内,对于Si和Na的Tm达成了良好的协议.
- 证明表面贡献不太可能普遍解释在散装固体中需要固体-液体共存方法的需要.
- 观察到对氧化物材料的Tm的一致,大幅高估,无论计算条件如何.
结论:
- 氧化物材料中Tm的高估可能是由于局部密度近似/一般化梯度近似 (LDA/GGA) 电子相关函数中固有的错误.
- 对于像Si和Na这样的元素固体,FP-MD具有适当的细胞大小和适应条件可以产生准确的Tm值.
- 这些发现为提高MD模拟用于预测材料点的可靠性提供了洞察力.
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