Pinney Rhiannon, Liverpool Tanniemola B, Royall C Patrick
HH Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
School of Mathematics, University of Bristol, Bristol BS8 1TW, United Kingdom.
J Chem Phys. 2015 Dec 28;143(24):244507. doi: 10.1063/1.4938424.
We consider a binary Lennard-Jones glassformer whose super-Arrhenius dynamics are correlated with the formation of icosahedral structures. Upon cooling, these icosahedra organize into mesoclusters. We recast this glassformer as an effective system of icosahedra which we describe with a population dynamics model. This model we parameterize with data from the temperature regime accessible to molecular dynamics simulations. We then use the model to determine the population of icosahedra in mesoclusters at arbitrary temperature. Using simulation data to incorporate dynamics into the model, we predict relaxation behavior at temperatures inaccessible to conventional approaches. Our model predicts super-Arrhenius dynamics whose relaxation time remains finite for non-zero temperature.
我们考虑一种二元 Lennard-Jones 玻璃形成体，其超阿伦尼乌斯动力学与二十面体结构的形成相关。冷却时，这些二十面体组织成介观团簇。我们将这种玻璃形成体重铸为一个有效的二十面体系统，并用种群动力学模型来描述它。我们用分子动力学模拟可及温度范围内的数据对该模型进行参数化。然后我们使用该模型来确定任意温度下介观团簇中二十面体的数量。利用模拟数据将动力学纳入模型，我们预测了传统方法无法达到的温度下的弛豫行为。我们的模型预测了超阿伦尼乌斯动力学，其弛豫时间在非零温度下保持有限。
