Padilla Espinosa Ingrid M, Jacobs Tevis D B, Martini Ashlie
Department of Mechanical Engineering, University of California, Merced, Merced, California 95340, United States.
Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
J Chem Theory Comput. 2021 Jul 13;17(7):4486-4498. doi: 10.1021/acs.jctc.1c00434. Epub 2021 Jun 1.
Understanding the size- and shape-dependent properties of platinum nanoparticles is critical for enabling the design of nanoparticle-based applications with optimal and potentially tunable functionality. Toward this goal, we evaluated nine different empirical potentials with the purpose of accurately modeling faceted platinum nanoparticles using molecular dynamics simulation. First, the potentials were evaluated by computing bulk and surface properties-surface energy, lattice constant, stiffness constants, and the equation of state-and comparing these to prior experimental measurements and quantum mechanics calculations. Then, the potentials were assessed in terms of the stability of cubic and icosahedral nanoparticles with faces in the {100} and {111} planes, respectively. Although none of the force fields predicts all the evaluated properties with perfect accuracy, one potential-the embedded atom method formalism with a specific parameter set-was identified as best able to model platinum in both bulk and nanoparticle forms.
了解铂纳米颗粒的尺寸和形状相关特性对于设计具有最佳且可能可调功能的基于纳米颗粒的应用至关重要。为了实现这一目标，我们评估了九种不同的经验势，目的是使用分子动力学模拟对多面铂纳米颗粒进行精确建模。首先，通过计算体相和表面性质——表面能、晶格常数、刚度常数和状态方程——来评估这些势，并将其与先前的实验测量值和量子力学计算结果进行比较。然后，根据分别具有{100}和{111}面的立方和二十面体纳米颗粒的稳定性来评估这些势。尽管没有一个力场能以完美的精度预测所有评估的性质，但一种势——具有特定参数集的嵌入原子方法形式——被确定为最能对块状和纳米颗粒形式的铂进行建模。
