Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342, USA.
J Chem Phys. 2011 Dec 14;135(22):224501. doi: 10.1063/1.3664180.
The term "strongly correlating liquids" refers to materials exhibiting near proportionality of fluctuations in the potential energy and the virial pressure, as seen in molecular dynamics simulations of liquids whose interactions are comprised primarily of van der Waals forces. Recently it was proposed that the Prigogine-Defay ratio, Π, of strongly correlating liquids should fall close to unity. We verify this prediction herein by showing that the degree to which relaxation times are a function T/ρ(γ), the ratio of temperature to density with the latter raised to a material constant (a property inherent to strongly correlating liquids) is reflected in values of Π closer to unity. We also show that the dynamics of strongly correlating liquids are governed more by density than by temperature. Thus, while Π may never strictly equal 1 for the glass transition, it is approximately unity for many materials, and thus can serve as a predictor of other dynamic behavior. For example, Π ≫ 1 is indicative of additional control parameters besides T/ρ(γ).
“强关联液体”一词是指在主要由范德华力相互作用的液体的分子动力学模拟中，势能和维里压力的涨落表现出近乎比例关系的材料。最近有人提出，强关联液体的普里戈金-德费比值 Π 应接近 1。我们通过证明弛豫时间与温度 T/ρ(γ)（密度 ρ 与γ的函数，γ是材料常数，后者的温度）的函数的程度在 Π 值更接近 1 时得到了这一预测的验证。我们还表明，强关联液体的动力学受密度的影响大于温度的影响。因此，尽管对于玻璃化转变，Π 可能永远不会严格等于 1，但对于许多材料，它近似于 1，因此可以作为其他动态行为的预测指标。例如，Π＞1 表示除了 T/ρ(γ) 之外还有其他控制参数。
