Enhancement of the Wolf Damped Coulomb Potential:  Static, Dynamic, and Dielectric Properties of Liquid Water from Molecular Simulation

We show that finite-range alternatives to the standard long-range BKS pair potential for silica might be used in molecular dynamics simulations. We study two such models that can be efficiently simulated since no Ewald summation is required. We first consider the Wolf method, where the Coulomb interactions are truncated at a cutoff distance rc such that the requirement of charge neutrality holds. Various static and dynamic quantities are computed and compared to results from simulations using Ewald summations. We find very good agreement for rc ≈ 10Å. For lower values of rc, the long-range structure is affected which is accompanied by a slight acceleration of dynamic properties. In a second approach, the Coulomb interaction is replaced by an effective Yukawa interaction with two new parameters determined by a force fitting procedure. The same trend as for the Wolf method is seen. However, slightly larger cutoffs have to be used in order to obtain the same accuracy with respect to static and dynamic quantities as for the Wolf method.

“…[19,20,39,44] and references therein). In these studies, screened Coulomb or Yukawa potentials have been considered as alternatives to the Wolf method presented above.…”

Section: Yukawa Screeningmentioning

confidence: 99%

Amorphous silica modeled with truncated and screened Coulomb interactions: A molecular dynamics simulation study

Carré

Berthier

Horbach

et al. 2007

“…However, the critical issue to the short-range treatment is to improve its accuracy and remove the possible artifacts arising in it. [10][11][12][13][14] As one of the approaches to address this issue in a shortrange treatment, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] the zero-multipole (summation) method (ZMM) has been developed. 30 The underlying physical idea is simple, as follows.…”

Section: Introductionmentioning

confidence: 99%

A critical appraisal of the zero-multipole method: Structural, thermodynamic, dielectric, and dynamical properties of a water system

Wang

Nakamura

Fukuda

2016

THE JOURNAL OF CHEMICAL PHYSICS 144, 114503 (2016) A critical appraisal of the zero-multipole method: Structural, thermodynamic, dielectric, and dynamical properties of a water system We performed extensive and strict tests for the reliability of the zero-multipole (summation) method (ZMM), which is a method for estimating the electrostatic interactions among charged particles in a classical physical system, by investigating a set of various physical quantities. This set covers a broad range of water properties, including the thermodynamic properties (pressure, excess chemical potential, constant volume/pressure heat capacity, isothermal compressibility, and thermal expansion coefficient), dielectric properties (dielectric constant and Kirkwood-G factor), dynamical properties (diffusion constant and viscosity), and the structural property (radial distribution function). We selected a bulk water system, the most important solvent, and applied the widely used TIP3P model to this test. In result, the ZMM works well for almost all cases, compared with the smooth particle mesh Ewald (SPME) method that was carefully optimized. In particular, at cut-off radius of 1.2 nm, the recommended choices of ZMM parameters for the TIP3P system are α ≤ 1 nm −1 for the splitting parameter and l = 2 or l = 3 for the order of the multipole moment. We discussed the origin of the deviations of the ZMM and found that they are intimately related to the deviations of the equilibrated densities between the ZMM and SPME, while the magnitude of the density deviations is very small. C 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

“…[11][12][13] Recently, substantial efforts have been put forward to develop reliable electrostatic treatments that take advantage of the efficiency of the cutoff-based schemes with an aim to remove the charge-dependent artifacts. 6,[14][15][16][17] This is achieved a) Electronic mail: jpu@iupui.edu in some methods by using a counter-charge term, which in effect makes the cutoff sphere neutral. Examples of this kind include, the simple zero-charge (ZC) method 6, 18 wherein a single correction term is added to the normal cutoff summation and the Wolf method 6 wherein an additional damping factor is further applied.…”

Section: Introductionmentioning

confidence: 99%

Assessing the accuracy of the isotropic periodic sum method through Madelung energy computation

Ojeda-May

2014

We tested the isotropic periodic sum (IPS) method for computing Madelung energies of ionic crystals. The performance of the method, both in its nonpolar (IPSn) and polar (IPSp) forms, was compared with that of the zero-charge and Wolf potentials [D. Wolf, P. Keblinski, S. R. Phillpot, and J. Eggebrecht, J. Chem. Phys. 110, 8254 (1999)]. The results show that the IPSn and IPSp methods converge the Madelung energy to its reference value with an average deviation of ∼10 −4 and ∼10 −7 energy units, respectively, for a cutoff range of 18-24a (a/2 being the nearest-neighbor ion separation). However, minor oscillations were detected for the IPS methods when deviations of the computed Madelung energies were plotted on a logarithmic scale as a function of the cutoff distance. To remove such oscillations, we introduced a modified IPSn potential in which both the localregion and long-range electrostatic terms are damped, in analogy to the Wolf potential. With the damped-IPSn potential, a smoother convergence was achieved. In addition, we observed a better agreement between the damped-IPSn and IPSp methods, which suggests that damping the IPSn potential is in effect similar to adding a screening potential in IPSp. © 2014 AIP Publishing LLC.