论文标题
微观模拟的宏观表面电荷
Macroscopic surface charges from microscopic simulations
论文作者
论文摘要
如果一个人旨在引起对系统行为的有意义的见解,则在分子模拟中获得准确的平均结构特性应被视为先决条件。对于与电解质溶液接触的带电表面,一个明显的例子是离子沿正常向表面的方向的密度曲线。在这里,我们证明,在模拟中通常使用的平板几何形状中,强加了电位移场$ d $确定带电接口处的吸附离子的集成表面电荷密度。这使我们能够获得宏观表面电荷密度,而与模拟中使用的平板厚度无关。我们还表明,常用的Yeh-Berkowitz方法和“镜面平板”几何形状都施加了消失的整合表面电荷密度。我们提出了相对简单的岩石(111)界面的结果,以及与水解溶液接触的高岭石基础面的更复杂的情况。
Attaining accurate average structural properties in a molecular simulation should be considered a prerequisite if one aims to elicit meaningful insights into a system's behavior. For charged surfaces in contact with an electrolyte solution, an obvious example is the density profile of ions along the direction normal to the surface. Here we demonstrate that, in the slab geometry typically used in simulations, imposing an electric displacement field $D$ determines the integrated surface charge density of adsorbed ions at charged interfaces. This allows us to obtain macroscopic surface charge densities irrespective of the slab thickness used in our simulations. We also show that the commonly used Yeh-Berkowitz method and the 'mirrored slab' geometry both impose vanishing integrated surface charge density. We present results both for relatively simple rocksalt (111) interfaces, and the more complex case of kaolinite's basal faces in contact with aqueous electrolyte solution.