DNRF Centre "Glass and Time", IMFUFA, Department of Science, Systems and Models, Roskilde University , Postbox 260, DK-4000 Roskilde, Denmark.
J Phys Chem B. 2012 May 17;116(19):5738-43. doi: 10.1021/jp300750g. Epub 2012 May 2.
In this paper we compare the Wolf method to the shifted forces (SF) method for efficient computer simulation of bulk systems with Coulomb forces, taking results from the Ewald summation and particle mesh Ewald methods as representing the true behavior. We find that for the Hansen-McDonald molten salt model the SF approximation overall reproduces the structural and dynamical properties as accurately as does the Wolf method. It is shown that the optimal Wolf damping parameter depends on the property in focus and that neither the potential energy nor the radial distribution function are useful measures for the convergence of the Wolf method to the Ewald summation method. The SF approximation is also tested for the SPC/Fw model of liquid water at room temperature, showing good agreement with both the Wolf and the particle mesh Ewald methods; this confirms previous findings [Fennell, C. J.; Gezelter, J. D. J. Chem. Phys.2006, 124, 234104]. Besides its conceptual simplicity, the SF approximation implies a speed-up of a factor of 2-3 compared to the Wolf method. We conclude that for the systems studied, whenever the Wolf method gives accurate results, it may be replaced by the simpler and faster SF method.
在本文中，我们将沃尔夫方法与移位力（SF）方法进行了比较，以有效地模拟具有库仑力的体相系统，其中埃瓦尔德求和和粒子网格埃瓦尔德方法的结果代表了真实的行为。我们发现，对于汉森-麦克唐纳熔融盐模型，SF 近似总体上可以像沃尔夫方法一样准确地再现结构和动力学性质。结果表明，最优的沃尔夫阻尼参数取决于关注的性质，而势能或径向分布函数都不是沃尔夫方法收敛到埃瓦尔德求和方法的有用度量。SF 近似还针对室温下的 SPC/Fw 模型的液态水进行了测试，与沃尔夫方法和粒子网格埃瓦尔德方法都吻合得很好；这证实了之前的发现[Fennell，C.J.；Gezelter，J.D. J.Chem.Phys.2006,124,234104]。除了概念上的简单性之外，SF 近似相对于沃尔夫方法提高了 2-3 倍的速度。我们的结论是，对于所研究的系统，只要沃尔夫方法给出了准确的结果，就可以用更简单、更快的 SF 方法来代替它。
