Modified Wolf electrostatic summation: Incorporating an empirical charge overlap

Abstract

The original Wolf sum [D. Wolf et al., J. Chem. Phys. 110 (1999) was modified to account for the effect of charge overlap in an empirical manner in order to correct the direct 1/r coulomb interaction in covalent systems. The resulting modified Wolf sum takes a form that is similar to the original one. More importantly, the inclusion of the charge overlap effect does not introduce any additional systematic error. Thus, the error analysis can be evaluated either analytically for 3D periodic systems or estimated numerically for general cases, which is the same as in the original Wolf sum. Application of this modified Wolf sum to covalent or partially covalent systems such as SiC and SiO 2 shows that it gives a more realistic description of the electrostatic interactions in those systems. Although the Wolf method does not conserve energy in principle, in practice the energy is conserved very well. Thus this method is particular suitable in molecular dynamics simulations.

Lattice dynamics and molecular-dynamics study of quartz using a many-body variable potential

“…The long-range Coulomb term is evaluated using a modified Wolf sum approach. 23,24 An important feature of this potential is that the parameters are allowed to vary as a function of system temperature, which essentially means that the system is able to evolve on a set of adiabatic Born-Oppenheimer surfaces. In most MD studies, a single potential energy surface ͑PES͒ is used in the consideration that any electronic variations are unimportant.…”

Atomic and micro‐structure features of nanoporous aluminosilicate glasses from reactive molecular dynamics simulations

“…where The charge based Madelung terms were treated with the Wolf summation with a universal damping parameter of β(=4.46Å) to estimate the long-range values. 32 The combination of two charge terms q and q d for each atom results in a diffuse charge distribution around the atoms. These chargebased terms were all determined based on an atomic species valency and the ionic charge values for hydrogen: +0.452e for q H and −0.113e for q d H , with charges of other species scale proportionally to the formal charges.…”

“…The charge based Madelung terms were treated with the Wolf summation with a universal damping parameter of β (=4.46Å) to estimate the long‐range values 32 . The combination of two charge terms q and q d for each atom results in a diffuse charge distribution around the atoms.…”

Difusión Selectiva de Hidrocarburos en Zeolitas de Poro Pequeño a Partir de Técnicas de Simulación Molecular

“…Entre estos están los potenciales basados en el modelo de igualación de cargas de Rappé y Goddard, 98 específicamente los potenciales de Demiralp et al 107 y Sefcik et al 99 Algunos otros potenciales desarrollados recientemente no han sido incluidos en este trabajo, debido principalmente a que su implementación en códigos estándar de simulación aún no ha sido llevada a cabo, y por tanto requerirían de su programación directa en códigos existentes. Algunos de estos potenciales son los desarrollados por Tilocca et al 118 o el modelo de la fluctuación de cargas de Tangney y Scandolo, 108,119 Olano y Rick, 120 y Garofalini et al 97,[121][122][123] La tabla 3.1 muestra las principales características de los potenciales seleccionados. La clasificación se da con respecto a: Figura 3.1: Diagrama de fases del cuarzo.…”

“…Este método es muy económico en gasto computacional y es usado como alternativa al método original de Ewald. 97,[121][122][123] La segunda parte de la ecuación de energía potencial 3.4 define los términos en los que puede incluirse la polarizabilidad atómica a partir del modelo CoreShell. Como regla general,únicamente los aniones están divididos en Core and Shell, representando de esta manera un par de cargas puntuales de signo contrario, donde la carga positiva está concentrada en el Núcleo (Core) y la negativa en la corteza electrónica (Shell).…”