预测Au55和Au147的形状:力场与密度函数理论
Shuiyi Zhang1, William L Robinson1, Kristen A Fichthorn1,2
1Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
The Journal of chemical physics
|September 3, 2025
概括
使用各种计算方法预测黄金纳米晶体结构显示无形,空心或无序的形状是最稳定的,挑战了传统的黄金纳米粒子假设.
科学领域:
- 计算材料科学
- 纳米技术
- 物理化学
背景情况:
- 黄金纳米晶体在传感和医学上至关重要,其形状对其特性产生重大影响.
- 准确预测金 (Au) 纳米材料的结构和特性依赖于第一原则研究.
- 对于Au存在各种力量场,但它们对结构的预测准确性需要澄清.
研究的目的:
- 评估不同计算方法在预测金纳米晶体结构的准确性.
- 使用各种力场探索Au147和Au55纳米粒子的温度依赖形状分布.
- 将预测的结构与来自密度函数理论 (DFT) 和机器学习模型的结构进行比较.
主要方法:
- 使用并行炼分子动力学模拟来研究Au147和Au55纳米粒子.
- 用三种不同的嵌入式原子法 (EAM) 力场来探索温度依赖的形状分布.
- 机器学习用于分类纳米粒子形状,并使用DFT重新优化结构.
主要成果:
- 在不同的EAM力场中观察到温度依赖的形状分布和化温度的显著变化.
- 正如人工神经网络 (ANN) 和DFT所预测的那样,Au147和Au55的最低能量结构被发现是无形的.
- 大多数低能结构是空洞或无序的,与这些纳米晶体大小的预期的二面体形状相矛盾.
结论:
- 这项研究强调了基于所选计算方法的金纳米晶体结构预测的变化.
- 无形,空洞或无序的结构代表了Au147和Au55纳米粒子最稳定的配置.
- 准确预测金纳米晶体形状需要先进的方法,如DFT和机器学习,超越传统假设.
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