Kale Seyit, Herzfeld Judith
Graduate Program in Biophysics and Structural Biology, Brandeis University, Waltham, MA 02454.
J Chem Theory Comput. 2011 Nov 8;7(11):3620-3624. doi: 10.1021/ct200392u.
We propose a pairwise compensation method for long-range electrostatics, as an alternative to traditional infinite lattice sums. The approach represents the third generation in a series beginning with the shifted potential corresponding to counterions surrounding a cutoff sphere. That simple charge compensation scheme resulted in pairwise potentials that are continuous at the cutoff, but forces that are not. A second-generation approach modified both the potential and the force such that both are continuous at the cutoff. Here we introduce another layer of softening such that the derivative of the force is also continuous at the cutoff. In strongly ionic liquids, this extension removes structural artifacts associated with the earlier pairwise compensation schemes, and provides results that compare well with Ewald sums.
我们提出了一种用于长程静电作用的成对补偿方法，作为传统无限晶格求和方法的替代方案。该方法是从围绕截止球的反离子对应的移位势开始的一系列方法中的第三代。那个简单的电荷补偿方案产生了在截止处连续的成对势，但力不连续。第二代方法对势和力都进行了修改，使得两者在截止处都连续。在这里，我们引入了另一层软化，使得力的导数在截止处也连续。在强离子液体中，这种扩展消除了与早期成对补偿方案相关的结构伪影，并提供了与埃瓦尔德求和相当的结果。
