Sanchez-Burgos Ignacio, Tejedor Andres R, Vega Carlos, Conde Maria M, Sanz Eduardo, Ramirez Jorge, Espinosa Jorge R
Cavendish Laboratory, Department of Physics, Maxwell Centre, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Department of Chemical Engineering, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006 Madrid, Spain.
J Chem Phys. 2022 Sep 7;157(9):094503. doi: 10.1063/5.0101383.
Freezing of water is the most common liquid-to-crystal phase transition on Earth; however, despite its critical implications on climate change and cryopreservation among other disciplines, its characterization through experimental and computational techniques remains elusive. In this work, we make use of computer simulations to measure the nucleation rate (J) of water at normal pressure under different supercooling conditions, ranging from 215 to 240 K. We employ two different water models: mW, a coarse-grained potential for water, and TIP4P/ICE, an atomistic nonpolarizable water model that provides one of the most accurate representations of the different ice phases. To evaluate J, we apply the Lattice Mold technique, a computational method based on the use of molds to induce the nucleus formation from the metastable liquid under conditions at which observing spontaneous nucleation would be unfeasible. With this method, we obtain estimates of the nucleation rate for ice Ih and Ic and a stacking mixture of ice Ih/Ic, reaching consensus with most of the previously reported rates, although differing with some others. Furthermore, we confirm that the predicted nucleation rates obtained by the TIP4P/ICE model are in better agreement with experimental data than those obtained through the mW potential. Taken together, our study provides a reliable methodology to measure nucleation rates in a simple and computationally efficient manner that contributes to benchmarking the freezing behavior of two popular water models.
水的冻结是地球上最常见的液-晶相变;然而,尽管其对气候变化和低温保存等学科具有关键影响,但通过实验和计算技术对其进行表征仍然难以实现。在这项工作中,我们利用计算机模拟来测量常压下不同过冷条件(215至240 K)下水的成核速率(J)。我们采用了两种不同的水模型:mW,一种水的粗粒度势模型;以及TIP4P/ICE,一种原子级不可极化水模型,它能最准确地表示不同的冰相。为了评估J,我们应用了晶格模具技术,这是一种基于使用模具在无法观察到自发成核的条件下诱导亚稳态液体形成晶核的计算方法。通过这种方法,我们获得了冰Ih和Ic以及冰Ih/Ic堆叠混合物的成核速率估计值,与之前报道的大多数速率达成了共识,尽管与其他一些速率有所不同。此外,我们证实,与通过mW势获得的预测成核速率相比,TIP4P/ICE模型获得的预测成核速率与实验数据的一致性更好。综上所述,我们的研究提供了一种可靠的方法,以简单且计算高效的方式测量成核速率,这有助于对两种常用水模型的冻结行为进行基准测试。