Departamento de Física, Universidade Federal de Santa Catarina, Caixa Postal 476, 88010-970, Florianópolis, SC, Brazil.
J Chem Phys. 2010 Sep 14;133(10):104904. doi: 10.1063/1.3479001.
In this paper we investigate the dynamic properties of the minimal Bell-Lavis (BL) water model and their relation to the thermodynamic anomalies. The BL model is defined on a triangular lattice in which water molecules are represented by particles with three symmetric bonding arms interacting through van der Waals and hydrogen bonds. We have studied the model diffusivity in different regions of the phase diagram through Monte Carlo simulations. Our results show that the model displays a region of anomalous diffusion which lies inside the region of anomalous density, englobed by the line of temperatures of maximum density. Further, we have found that the diffusivity undergoes a dynamic transition which may be classified as fragile-to-strong transition at the critical line only at low pressures. At higher densities, no dynamic transition is seen on crossing the critical line. Thus evidence from this study is that relation of dynamic transitions to criticality may be discarded.
在本文中，我们研究了最小贝尔-拉维斯（BL）水模型的动力学性质及其与热力学异常的关系。BL 模型定义在一个三角晶格上，其中水分子由具有三个对称键臂的粒子表示，通过范德华力和氢键相互作用。我们通过蒙特卡罗模拟研究了模型在相图不同区域的扩散性。我们的结果表明，该模型显示出异常扩散区域，位于异常密度区域内，被最大密度温度线所包围。此外，我们发现扩散率在临界线上经历了一个动态转变，仅在低压下可归类为脆弱到强的转变。在更高的密度下，在穿过临界线时没有观察到动态转变。因此，这项研究的证据表明，动力学转变与临界性之间的关系可能被摒弃。
